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Shedding Light on the Risks
& Benefits of Medications
Shedding Light on the Risks
& Benefits of Medications
From Ashwagandha to St. John’s Wort: The Risks Behind 5 Trending Supplements
Like prescription drugs, supplements have side effects — but without FDA oversight, consumers are often left to assess the risks on their own.
March 27, 2025
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Their bottles line drugstore aisles. Their ads interrupt your favorite podcast. Chances are, you have a few supplements in your kitchen cabinet right now. Maybe they’re already running through your bloodstream.
Dietary supplements are a booming industry—and their popularity keeps rising. According to Grandview Research, the supplement market is valued at $177 billion worldwide—and this is projected to balloon to more than $325 billion by 2030. Today, nearly three-quarters of adults in the United States occasionally take supplements, with 55% identifying as regular users.
While supplements are often framed as upside-only additives for your overall health, the Food and Drug Administration (FDA) does not have the authority to approve them before they hit the market. This means that supplement claims aren’t always backed by credible data, and the products aren’t tested for safety the way drugs are. As a result, benefits can be overpromised, while risks may only become apparent after widespread use.
Real Cases of Supplements With Dangerous Side Effects
“We know that the FDA does not require that supplements be tested before being sold, so the testing happens on the consumers, and it is the consumers who have the responsibility of identifying dangerous and faulty supplements,” says Mahtab Jafari, PharmD., professor of pharmaceutical sciences, in her book The Truth About Dietary Supplements.
For example, the weight-loss supplement ephedra was banned in 2004 only after reports of serious side effects, including heart attacks and induced psychosis, some even resulting in death. Similarly, comfrey, an herbal supplement used for digestive issues and joint pain, was banned in 2001 after it was linked to liver damage.
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These aren’t isolated cases. Many supplements that cause severe side effects remain on the market. In fact, a 2015 study found that adverse events from supplements are responsible for 23,000 ER visits a year.
“Many patients believe supplements are ‘natural’ and therefore harmless, but this isn’t true,” says Ana Reisdorf, a registered dietitian and creator of the healthy-eating blog, The Food Trends. “A common misunderstanding is assuming more is better, which can lead to toxicity or negative health effects.”
While many supplements can be beneficial for issues such as vitamin and mineral deficiencies, their risks — just like medications — should be weighed alongside their benefits.
5 Common Supplements and Their Surprising Side Effects
Here are some of today’s most popular supplements, along with potential side effects you may not be aware of.
Ashwagandha
What is it?: Made from the root of an evergreen shrub, ashwagandha has been used for centuries in Ayurvedic and Unani alternative-medicine systems.
Benefits: Clinical studies have found that ashwagandha may be helpful in treating stress and anxiety. In a recent meta-analysis of 12 eligible papers, researchers found that supplementation with ashwagandha reduced stress when taken at a dose of 300-600 mg/d and reduced anxiety at a dose of 12,000 mg/d. However, due to a lack of scrutiny in the studies, the authors of the meta- analysis noted the that the evidence shouldn’t be considered strong.
Risks: Side effects are typically mild (stomach upset or nausea) and the National Center for Complementary and Integrative Health says that the root may be safe when used for up to three months. However, there have been limited reports of liver injury for individuals taking the supplement for even short amounts of time (one week to four months). In all cases of healthy individuals, the liver problems self-corrected when the supplement was stopped. Patients with preexisting liver issues, on the other hand, have experienced acute liver injury.
“You have to be thoughtful here,” says Alison Acerra, a registered dietitian nutritionist and MedShadow Health and Medical Advisory Panelist. “If you’ve had elevated [liver function tests] in the past or have some sort of liver dysfunction, ashwagandha is going to be more risky — but it’s not very common.”
Additional research suggests that ashwagandha can also have an impact on thyroid function. Research has found that adults taking a dose of 300 mg/d for eight weeks saw evidence of elevated thyroid activity. Acerra says, “It could be potentially helpful for someone with hypothyroidism but detrimental for someone with hyperthyroidism.”
Ashwagandha may influence sex hormones, with some reports suggesting it can increase testosterone in men. In 2024, Denmark banned ashwagandha due to concerns about its effects on reproductive hormones, though critics argue that the decision lacks strong scientific backing. Despite the debate, the National Center for Complementary and Integrative Health advises against its use for those who are pregnant or breastfeeding.
Melatonin
What is it?: Melatonin is a naturally occurring hormone that helps to regulate our sleep-wake cycles. The brain releases the hormone in low light or darkness to prepare for sleep. Melatonin supplements contain a synthetic form of this hormone.
Benefits: Melatonin has been shown to have some benefits for adults with specific sleep disorders, including jet lag and delayed sleep-wake phase disorder. One 2015 meta-review also found that melatonin may be as effective as midazolam (a prescription benzodiazepine) at reducing anxiety before surgery. Melatonin may also improve sleep for children with conditions including autism spectrum disorder, ADHD, atopic dermatitis, and chronic sleep-onset insomnia.
Risks: While melatonin is considered safe in the short term, little is known about the long-term effects of taking this synthetic hormone. Research shows that melatonin may reduce fertility in women, especially when taken at high doses. It can also exacerbate depression in some people and may worsen symptoms of bleeding disorders and high blood pressure.
Acerra says that while she recommends melatonin to some patients (especially menopausal women) to help with sleep, it’s best to uncover the root cause of the sleep issues before treating them with a medication or supplement. “I think we want to be really cautious that we’re not ‘band-aiding’ an issue,” she says.
St. John’s Wort
What is it?: The medicinal use of this flowering plant dates back to ancient Greece. Historically, St. John’s wort (Hypericum perforatum) has been used to treat a number of conditions including kidney disease and depression.
Benefits: Some studies have shown St. John’s wort to be more effective than a placebo (which is to say, taking nothing) and possibly effective in easing some symptoms of depression. It may also help relieve premenstrual syndrome (PMS) symptoms, including cramping and mood swings, as well as symptoms related to menopause (hot flashes and depression). However, in all cases, researchers point out that what’s sold on the market can vary in their pharmaceutical makeup and that a study’s results apply only to the products tested for that study.
Risks: St. John’s wort carries a number of known side effects, including increased sensitivity to sun, making both the skin and the eyes more susceptible to sun damage. Other adverse effects include insomnia, increased anxiety, digestive distress, headache, and fatigue.
Men who take St. John’s wort may experience issues around sex, including reduced libido and erectile dysfunction. But Courtney Pelitera, a registered dietician with Top Nutrition Coaching, says that one of the biggest risks in taking St. John’s wort is not knowing how it will interact with other medications, both over-the-counter and prescription. “St. John’s Wort has many medication interactions, including warfarin, contraceptive medications, allergy medications, omeprazole, Xanax, and antidepressants,” she says.
Kava
What is it?: Made from the roots of a plant native to the South Pacific, kava is known to have sedative properties and psychoactive effects. Kava is sold as a pill, powder, tincture, or beverage.
Benefits: Some studies show that kava may be effective for generalized anxiety disorder (GAD). However, a recent double-blind, randomized, placebo-controlled study found no benefit over the course of 16 weeks. Kava is also used to improve sleep, but there’s limited research that it’s even effective for treating insomnia.
Risks: While kava is sometimes promoted as a “safe” alternative to alcohol, it’s been associated with liver toxicity. In fact, in 2002, the FDA issued an advisory that kava supplements are linked to cirrhosis, hepatitis, and liver failure. This is mainly because Kava has been found to reduce glutathione, an important antioxidant that helps protect the liver, while also slowing the enzymes that break down harmful substances. For that reason, using kava and alcohol together is warned against as the combination can greatly increase the risk of liver damage.
Even though kava is still readily sold as a dietary supplement, the FDA states that it is not generally recognized as safe (GRAS). Other adverse effects include vision impairment, rashes, nausea, and seizures.
Vitamin D
What is it?: Vitamin D is an essential fat-soluble vitamin that’s available in foods including eggs, seafood, and liver. It’s also a hormone produced naturally by our exposure to the sun. Available in supplement form, it’s one of the most widely used vitamins in the United States, long believed to help support bone and heart health.
Benefits: While our bodies do need vitamin D to maintain strong bones, taking vitamin D in supplement form may not actually improve bone health. In 2024, the U.S. Preventive Services Task Force published a draft recommendation stating that vitamin D supplements have no real benefit when it comes to the prevention of fractures in older adults.
One potential benefit is improved immunity. “We have vitamin D receptors all over the body,” says Acerra, “and it does seem to be helpful for the immune system.” Indeed, studies have found that vitamin D may have protective effects against respiratory infections in the general population (especially for those deficient in the vitamin) and certain strains of the flu virus in children.
Risks: In rare cases, taking excessively high doses of vitamin D (doses exceeding 10,000 IU/day), can be toxic, with symptoms ranging from weakness and fatigue to cardiac arrhythmia and coma. For context, the recommended daily amount of vitamin D for the general public, ages one to 70, including pregnant and breastfeeding women, is 600 IU/day, according to the National Institutes of Health. In 2021, U.S. poison control centers reported more than 11,000 instances of vitamin D toxicity, with the majority of cases being children 12 and under.
An excess of vitamin D can also make the intestines absorb too much calcium. This can lead to kidney stones, calcium deposits in the heart and lungs, weakness, and disorientation. If you do choose to supplement with vitamin D, some experts recommend a formulation that combines vitamin D with vitamin K2 to help avoid this issue. “Vitamin K2 can help by moving calcium out of the arteries and into the bones,” says Acerra.
Supplements and Medication Interactions
Most people who take supplements usually don’t consider them as serious or important as their prescription medications. This probably accounts for why some 75% of adults in this country don’t think to disclose their supplement use to their doctors. However, the FDA warns that mixing certain supplements with a variety of medications can be dangerous.
“It’s crucial to consult a healthcare provider before combining supplements with medications,” says Mascha Davis, a registered dietitian nutritionist and author of Eat Your Vitamins. Davis explains that even a simple calcium supplement, for example, can block antibiotic absorption, thereby reducing its ability to fight infection.
How to Find Quality Supplements
According to the National Institutes of Health (NIH), dietary supplements may be appropriate for those who don’t get sufficient nutrients from their diet. However, “the best way to ensure you are taking the correct supplements in an appropriate dose is to get bloodwork done and have your labs properly evaluated by a doctor or registered dietitian,” says Pelitera.
If you do need a dietary supplement, Davis recommends discussing your options with a healthcare professional who can help you choose a high-quality option. In her practice, Davis looks for third-party-testing certifications, such as ConsumerLab, US Pharmacopeia (USP), and the National Science Foundation (NSF), all of which indicate that the product has been tested for potency and purity. She also examines the label to avoid supplement products with harmful additives or artificial dyes.
While supplements can support health, they can also pose unexpected risks when taken incorrectly, which includes mixing with medications or taken in doses that are too high for what you need. Since supplements do not have the benefit of FDA oversight, it’s up to consumers to do their own research. Check for certifications, read up on the different brands, and most importantly, talk to a healthcare professional before randomly adding any supplement to your routine to make sure it’s right for you.
- Grand View Research. (n.d.). Dietary supplements market size & trends. Grand View Research.
- Council for Responsible Nutrition. (2023, October 18). Three-quarters of Americans take dietary supplements.
- U.S. Food and Drug Administration. (2024, February 21). Questions and answers on dietary supplements. FDA.
- U.S. Food and Drug Administration. (2024, March 28). Label claims for conventional foods and dietary supplements. FDA.
- Mph, T. J. K. M. (2021). Banned, but not forgotten: a case of Ephedrine-Induced psychosis. Psychiatrist.com.
- FTC announces a second case focusing on safety risks of Comfrey products promoted via internet. (2001, July 13). Federal Trade Commission.
- Office of Dietary Supplements – Dietary supplements: What you need to know. (n.d.).
- Geller, A. I., Shehab, N., Weidle, N. J., Lovegrove, M. C., Wolpert, B. J., Timbo, B. B., Mozersky, R. P., & Budnitz, D. S. (2015). Emergency department visits for adverse events related to dietary supplements. New England Journal of Medicine, 373(16), 1531–1540.
- Office of Dietary Supplements – Ashwagandha: Is it helpful for stress, anxiety, or sleep? (n.d.).
- Akhgarjand, C., Asoudeh, F., Bagheri, A., et al. (2022). Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials. Phytotherapy research : PTR, 36(11), 4115–4124.
- National Center for Complementary and Integrative Health. (2023, March). Ashwagandha. National Institutes of Health.
- Office of Dietary Supplements. (2024, December 5). Ashwagandha: Health professional fact sheet. National Institutes of Health.
- Sharma, A. K., Basu, I., & Singh, S. (2018). Efficacy and safety of Ashwagandha root extract in subclinical hypothyroid patients: A double-blind, randomized placebo-controlled trial. Journal of Alternative and Complementary Medicine (New York, N.Y.), 24(3), 243–248.
- Lopresti, A. L., Drummond, P. D., & Smith, S. J. (2019). A randomized, double-blind, placebo-controlled, crossover study examining the hormonal and vitality effects of Ashwagandha in aging, overweight males. American Journal of Men’s Health, 13(2), 1557988319835985.
- Patwardhan, B., Chaturvedi, S., Tillu, G., Deshpande, S., & Hegde, B. M. (2024). Danish ban on Ashwagandha: Truth, evidence, ethics, and regulations. Journal of Ayurveda and Integrative Medicine, 15(4), 101028.
- National Center for Complementary and Integrative Health. (2024, May). Melatonin: What you need to know. National Institutes of Health.
- Hansen, M. V., Halladin, N. L., Rosenberg, J., Gögenur, I., & Møller, A. M. (2015). Melatonin for pre- and postoperative anxiety in adults. The Cochrane Database of Systematic Reviews, 2015(4), CD009861
- Skrzelowski, M., Brookhaus, A., Shea, L. A., & Berlau, D. J. (2021). Melatonin use in pediatrics: Evaluating the discrepancy in evidence based on country and regulations regarding production. The Journal of Pediatric Pharmacology and Therapeutics, 26(1), 4–20.
- MedlinePlus. (2024, July 9). Melatonin. U.S. National Library of Medicine.
- Treister-Goltzman, Y., & Peleg, R. (2021). Melatonin and the health of menopausal women: A systematic review. Journal of Pineal Research, 71(2), e12743.
- National Center for Complementary and Integrative Health. (2020, October). St. John’s wort. National Institutes of Health
- Linde, K., Berner, M. M., & Kriston, L. (2008). St John’s wort for major depression. The Cochrane Database of Systematic Reviews, 2008(4), CD000448.
- Rapaport, M. H., Nierenberg, A. A., Howland, R., Dording, C., Schettler, P. J., & Mischoulon, D. (2011). The treatment of minor depression with St. John’s Wort or citalopram: Failure to show benefit over placebo. Journal of Psychiatric Research, 45(7), 931–941.
- Canning, S., Waterman, M., Orsi, N., Ayres, J., Simpson, N., & Dye, L. (2010). The efficacy of Hypericum perforatum (St John’s wort) for the treatment of premenstrual syndrome: A randomized, double-blind, placebo-controlled trial. CNS Drugs, 24(3), 207–225.
- Abdi, F., Mobedi, H., Mosaffa, N., & Dolatian, M. (2020). The effect of Hypericum perforatum on postmenopausal symptoms: A randomized clinical trial. Phytomedicine, 68, 153179.
- He, Y. Y., Chignell, C. F., Miller, D. S., Andley, U. P., & Roberts, J. E. (2004). Phototoxicity in human lens epithelial cells promoted by St. John’s Wort. Photochemistry and Photobiology, 80(3), 583–586.
- Alzahrani, M. A., Ofisan, S. B., Alshumaymiri, N. I., Alghuwainem, M., Altamimi, M., Alali, A. Y., Rabie, M., AboSkena, A. K., Almaymuni, K., Almannie, R., & Binsaleh, S. (2023). Effect of St. John’s Wort (Hypericum perforatum L.) on male sexual and reproductive health: A narrative review. Biomedicines, 11(10), 2800.
- University of Colorado Anschutz Medical Campus. (2025, January 4). Kava for Dry January? A look at the alcohol alternative. Department of Medicine.
- Savage, K. M., Stough, C. K., Byrne, G. J., Scholey, A., Bousman, C., Murphy, J., Macdonald, P., Suo, C., Hughes, M., Thomas, S., Teschke, R., Xing, C., & Sarris, J. (2015). Kava for the treatment of generalised anxiety disorder (K-GAD): Study protocol for a randomised controlled trial. Trials, 16, 493
- Sarris, J., Byrne, G. J., Bousman, C. A., Cribb, L., Savage, K. M., Holmes, O., Murphy, J., Macdonald, P., Short, A., Nazareth, S., Jennings, E., Thomas, S. R., Ogden, E., Chamoli, S., Scholey, A., & Stough, C. (2020). Kava for generalised anxiety disorder: A 16-week double-blind, randomised, placebo-controlled study. The Australian and New Zealand Journal of Psychiatry, 54(3), 288–297.
- Shinomiya, K., Inoue, T., Utsu, Y., Tokunaga, S., Masuoka, T., Ohmori, A., & Kamei, C. (2005). Effects of kava-kava extract on the sleep-wake cycle in sleep-disturbed rats. Psychopharmacology, 180(3), 564–569.
- UCLA Health. (2018, September 18). Ask the doctors: What are the risks and benefits of kava? UCLA Health News & Insights.
- Office of Dietary Supplements. (n.d.). Kava. National Institutes of Health.
- Alcohol and Drug Foundation. (2025, March 7). Kava
- U.S. Food and Drug Administration. (2020, August 11). Dietary supplement ingredient advisory list. FDA
- California Department of Public Health. (2024, May 21). Kava fact sheet.
- MedlinePlus. (n.d.). Vitamin D. U.S. National Library of Medicine.
- National Center for Health Statistics. (2023). Dietary supplement use among U.S. adults, 2017–March 2020. Centers for Disease Control and Prevention.
- U.S. Preventive Services Task Force. (2024, December 17). Vitamin D and calcium supplementation for the primary prevention of falls and fractures in community-dwelling adults: Draft recommendation.
- Office of Dietary Supplements. (2022, November 8). Vitamin D: Fact sheet for consumers. National Institutes of Health.
- Centers for Disease Control and Prevention. (2020). Trends in dietary supplement use among US adults from 2007 to 2016. Preventing Chronic Disease, 17, E138.
- Bolland, M. J., Grey, A., Gamble, G. D., & Reid, I. R. (2017). Calcium and vitamin D supplements and health outcomes: A reanalysis of the Women’s Health Initiative (WHI). BMJ, 356, i6583.
- Urashima, M., Segawa, T., Okazaki, M., Kurihara, M., Wada, Y., & Ida, H. (2010). Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. American Journal of Clinical Nutrition, 91(5), 1255–1260.
- Marcinowska-Suchowierska, E., Kupisz-Urbańska, M., Łukaszkiewicz, J., Płudowski, P., & Jones, G. (2018). Vitamin D toxicity—A clinical perspective. Frontiers in Endocrinology, 9, 550.
- Asif, A., & Farooq, N. (2023, May 24). Vitamin D toxicity. In StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing
- Gummin, D. D., Mowry, J. B., Beuhler, M. C., Spyker, D. A., Rivers, L. J., Feldman, R., Brown, K., Pham, P. T., Bronstein, A. C., & Weber, J. A. (2022). 2021 Annual Report of the National Poison Data System (NPDS) from America’s Poison Centers: 39th Annual Report. Clinical Toxicology, 60(12), 1381–1643.
- MedlinePlus. (2023, January 19). Vitamin D deficiency. U.S. National Library of Medicine.
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<p>Their bottles line drugstore aisles. Their ads interrupt your favorite podcast. Chances are, you have a few supplements in your kitchen cabinet right now. Maybe they’re already running through your bloodstream.</p>
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<p>Dietary supplements are a booming industry—and their popularity keeps rising. According to Grandview Research, the supplement market is valued at <a href="https://www.grandviewresearch.com/industry-analysis/dietary-supplements-market-report#:~:text=Dietary%20Supplements%20Market%20Size%20%26%20Trends,9.1%25%20from%202024%20to%202030." target="_blank" rel="noreferrer noopener">$177 billion worldwide</a>—and this is projected to balloon to more than $325 billion by 2030. Today, nearly <a href="https://www.crnusa.org/newsroom/three-quarters-americans-take-dietary-supplements-most-users-agree-they-are-essential?utm_source=chatgpt.com" target="_blank" rel="noreferrer noopener">three-quarters of adults</a> in the United States occasionally take supplements, with <a href="https://www.crnusa.org/newsroom/three-quarters-americans-take-dietary-supplements-most-users-agree-they-are-essential?utm_source=chatgpt.com" target="_blank" rel="noreferrer noopener">55% identifying as regular users</a>.</p>
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<p>While supplements are often framed as upside-only additives for your overall health, the Food and Drug Administration (FDA) <a href="https://www.fda.gov/food/information-consumers-using-dietary-supplements/questions-and-answers-dietary-supplements" target="_blank" rel="noreferrer noopener">does not have the authority to approve them</a> before they hit the market. This means that supplement claims <a href="https://www.fda.gov/food/nutrition-food-labeling-and-critical-foods/label-claims-conventional-foods-and-dietary-supplements" target="_blank" rel="noreferrer noopener">aren’t always backed by credible data</a>, and the products aren’t tested for safety the way drugs are. As a result, benefits can be overpromised, while risks may only become apparent after widespread use.</p>
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<h2 class="wp-block-heading">Real Cases of Supplements With Dangerous Side Effects</h2>
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<p>“We know that the FDA does not require that supplements be tested before being sold, so the testing happens on the consumers, and it is the consumers who have the responsibility of identifying dangerous and faulty supplements,” says <a href="https://faculty.sites.uci.edu/jafarilab/dr-mahtab-jafari-edit/" target="_blank" rel="noreferrer noopener">Mahtab Jafari</a>, PharmD., professor of pharmaceutical sciences, in her book <em>The Truth About Dietary Supplements</em>.</p>
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<p>For example, the weight-loss supplement <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC474739/" target="_blank" rel="noreferrer noopener">ephedra was banned in 2004</a> only after reports of serious side effects, including heart attacks and induced psychosis, some even resulting in death. Similarly, comfrey, an herbal supplement used for digestive issues and joint pain, was <a href="https://www.ftc.gov/news-events/news/press-releases/2001/07/ftc-announces-second-case-focusing-safety-risks-comfrey-products-promoted-internet" target="_blank" rel="noreferrer noopener">banned in 2001 </a>after it was linked to liver damage.</p>
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<p>These aren’t isolated cases. Many supplements that cause severe side effects <a href="https://ods.od.nih.gov/factsheets/WYNTK-Consumer/" target="_blank" rel="noreferrer noopener">remain on the market</a>. In fact, a 2015 study found that adverse events from supplements are responsible for <a href="https://www.nejm.org/doi/full/10.1056/nejmsa1504267" target="_blank" rel="noreferrer noopener">23,000 ER visits a year</a>.</p>
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<p>“Many patients believe supplements are ‘natural’ and therefore harmless, but this isn’t true,” says Ana Reisdorf, a registered dietitian and creator of the healthy-eating blog, The Food Trends. “A common misunderstanding is assuming more is better, which can lead to toxicity or negative health effects.”</p>
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<p>While many supplements can be beneficial for issues such as vitamin and mineral deficiencies, their risks — just like medications — should be weighed alongside their benefits.</p>
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<h2 class="wp-block-heading">5 Common Supplements and Their Surprising Side Effects</h2>
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<p>Here are some of today’s most popular supplements, along with potential side effects you may not be aware of.</p>
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<h3 class="wp-block-heading">Ashwagandha</h3>
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<p><strong>What is it?:</strong> Made from the root of an evergreen shrub, ashwagandha has been used for centuries in <a href="https://ods.od.nih.gov/factsheets/Ashwagandha-HealthProfessional/" target="_blank" rel="noreferrer noopener">Ayurvedic and Unani alternative-medicine</a> systems.</p>
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<p><strong>Benefits</strong>: Clinical studies have found that ashwagandha may be helpful in treating stress and anxiety. In a recent <a href="https://www.researchgate.net/publication/362948981_Does_Ashwagandha_supplementation_have_a_beneficial_effect_on_the_management_of_anxiety_and_stress_A_systematic_review_and_meta-analysis_of_randomized_controlled_trials" target="_blank" rel="noreferrer noopener">meta-analysis of 12 eligible papers</a>, researchers found that supplementation with ashwagandha reduced stress when taken at a dose of 300-600 mg/d and reduced anxiety at a dose of 12,000 mg/d. However, due to a lack of scrutiny in the studies, the authors of the meta- analysis noted the that the evidence shouldn’t be considered strong.</p>
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<p><strong>Risks</strong>: Side effects are typically mild (<a href="https://www.nccih.nih.gov/health/ashwagandha" target="_blank" rel="noreferrer noopener">stomach upset or nausea</a>) and the <a href="https://www.nccih.nih.gov/health/ashwagandha" target="_blank" rel="noreferrer noopener">National Center for Complementary and Integrative Health</a> says that the root may be safe when used for up to three months. However, there have been limited reports of <a href="https://ods.od.nih.gov/factsheets/Ashwagandha-HealthProfessional/#en24" target="_blank" rel="noreferrer noopener">liver injury </a>for individuals taking the supplement for even short amounts of time (one week to four months). In all cases of healthy individuals, the liver problems self-corrected when the supplement was stopped. Patients with <a href="https://ods.od.nih.gov/factsheets/Ashwagandha-HealthProfessional/#en24" target="_blank" rel="noreferrer noopener">preexisting liver issues</a>, on the other hand, have experienced acute liver injury.</p>
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<p>“You have to be thoughtful here,” says Alison Acerra, a registered dietitian nutritionist and <a href="https://medshadow.org/associates/alison-acerra-ms-rdn/" target="_blank" rel="noreferrer noopener">MedShadow Health and Medical Advisory </a>Panelist. “If you’ve had elevated [liver function tests] in the past or have some sort of liver dysfunction, ashwagandha is going to be more risky — but it’s not very common.”</p>
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<p>Additional research suggests that ashwagandha can also have an impact on thyroid function. <a href="https://pubmed.ncbi.nlm.nih.gov/28829155/" target="_blank" rel="noreferrer noopener">Research has found that adults</a> taking a dose of 300 mg/d for eight weeks saw evidence of elevated thyroid activity. Acerra says, “It could be potentially helpful for someone with hypothyroidism but detrimental for someone with hyperthyroidism.”</p>
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<p>Ashwagandha may influence sex hormones, with some reports suggesting it can <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC6438434/" target="_blank" rel="noreferrer noopener">increase testosterone in men</a>. In 2024, <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC11403136/" target="_blank" rel="noreferrer noopener">Denmark banned ashwagandha</a> due to concerns about its effects on reproductive hormones, though critics argue that the decision lacks strong scientific backing. Despite the debate, the <a href="https://www.nccih.nih.gov/health/ashwagandha#:~:text=In%20some%20individuals%2C%20ashwagandha%20preparations,not%20be%20used%20while%20breastfeeding." target="_blank" rel="noreferrer noopener">National Center for Complementary and Integrative Health</a> advises against its use for those who are pregnant or breastfeeding.</p>
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<h3 class="wp-block-heading">Melatonin</h3>
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<p><strong>What is it?</strong>: Melatonin is a naturally occurring hormone that helps to <a href="https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know#:~:text=Melatonin%20dietary%20supplements%20can%20be,often%20they're%20made%20synthetically." target="_blank" rel="noreferrer noopener">regulate our sleep-wake cycles</a>. The brain releases the hormone in low light or darkness to prepare for sleep. Melatonin supplements contain a synthetic form of this hormone.</p>
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<p><strong>Benefits</strong>: Melatonin has been shown to have some benefits for <a href="https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know#:~:text=Melatonin%20dietary%20supplements%20can%20be,often%20they're%20made%20synthetically." target="_blank" rel="noreferrer noopener">adults with specific sleep disorders</a>, including jet lag and delayed sleep-wake phase disorder. One <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC6464333/" target="_blank" rel="noreferrer noopener">2015 meta-review</a> also found that melatonin may be as effective as midazolam (a prescription benzodiazepine) at reducing anxiety before surgery. <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC7792147/" target="_blank" rel="noreferrer noopener">Melatonin may also improve sleep for children</a> with conditions including autism spectrum disorder, ADHD, atopic dermatitis, and chronic sleep-onset insomnia.</p>
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<p><strong>Risks</strong>: While melatonin is considered safe in the short term, little is known about the long-term effects of taking this synthetic hormone. <a href="https://medlineplus.gov/druginfo/natural/940.html" target="_blank" rel="noreferrer noopener">Research shows</a> that melatonin may reduce fertility in women, especially when taken at high doses. It can also exacerbate depression in some people and may worsen symptoms of bleeding disorders and high blood pressure.</p>
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<p>Acerra says that while she recommends melatonin to some patients (<a href="https://pubmed.ncbi.nlm.nih.gov/33969545/" target="_blank" rel="noreferrer noopener">especially menopausal women</a>) to help with sleep, it’s best to uncover the root cause of the sleep issues before treating them with a medication or supplement. “I think we want to be really cautious that we’re not ‘band-aiding’ an issue,” she says.</p>
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<h3 class="wp-block-heading">St. John’s Wort</h3>
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<p><strong>What is it</strong>?: The medicinal use of this flowering plant dates back to ancient Greece. Historically, St. John’s wort (Hypericum perforatum) has been used to treat a number of conditions including <a href="https://www.nccih.nih.gov/health/st-johns-wort" target="_blank" rel="noreferrer noopener">kidney disease and depression</a>.</p>
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<p><strong>Benefits</strong>: <a href="https://pubmed.ncbi.nlm.nih.gov/18843608/" target="_blank" rel="noreferrer noopener">Some studies</a> have shown St. John’s wort to be more effective than a placebo (which is to say, taking nothing) and possibly effective in easing some symptoms of depression. It may also help <a href="https://pubmed.ncbi.nlm.nih.gov/20155996/" target="_blank" rel="noreferrer noopener">relieve premenstrual syndrome</a> (PMS) symptoms, including cramping and mood swings, as well as <a href="https://www.sciencedirect.com/science/article/abs/pii/S0965229919305631" target="_blank" rel="noreferrer noopener">symptoms related to menopause</a> (hot flashes and depression). However, in all cases, researchers point out that what’s sold on the market can vary in their pharmaceutical makeup and that a study’s results apply only to the products tested for that study.</p>
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<p><strong>Risks</strong>: St. John’s wort carries a number of known side effects, including increased <a href="https://pubmed.ncbi.nlm.nih.gov/15623347/" target="_blank" rel="noreferrer noopener">sensitivity to sun</a>, making both the skin and the eyes more susceptible to sun damage. <a href="https://pubmed.ncbi.nlm.nih.gov/20155996/" target="_blank" rel="noreferrer noopener">Other adverse effects</a> include insomnia, increased anxiety, digestive distress, headache, and fatigue.</p>
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<p>Men who take St. John’s wort may experience <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC10604084/#:~:text=These%20studies%20demonstrate%20variability%20in,delayed%20orgasm%2C%20and%20erectile%20dysfunction." target="_blank" rel="noreferrer noopener">issues around sex</a>, including reduced libido and erectile dysfunction. But Courtney Pelitera, a registered dietician with Top Nutrition Coaching, says that one of the biggest risks in taking St. John’s wort is not knowing how it will interact with other medications, both over-the-counter and prescription. “St. John’s Wort has many medication interactions, including <a href="https://medshadow.org/can-i-take-fish-oil-with-warfarin/#:~:text=Saouma.,have%20had%20a%20heart%20attack." target="_blank" rel="noreferrer noopener">warfarin</a>, contraceptive medications, allergy medications, omeprazole, Xanax, and <a href="https://medshadow.org/antidepressants-post-ssri-sexual-dysfunction-protection/" target="_blank" rel="noreferrer noopener">antidepressants</a>,” she says.</p>
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<h3 class="wp-block-heading">Kava</h3>
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<p><strong>What is it?:</strong> Made from the roots of a plant native to the South Pacific, kava is known to have sedative properties and <a href="https://news.cuanschutz.edu/department-of-medicine/kava-dry-january-alcohol-alternative" target="_blank" rel="noreferrer noopener">psychoactive effects</a>. Kava is sold as a pill, powder, tincture, or beverage.</p>
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<p><strong>Benefits</strong>: Some studies show that kava may be effective for <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC4630875/" target="_blank" rel="noreferrer noopener">generalized anxiety disorder (GAD)</a>. However, a recent double-blind, randomized, placebo-controlled <a href="https://pubmed.ncbi.nlm.nih.gov/31813230/" target="_blank" rel="noreferrer noopener">study found no benefit</a> over the course of 16 weeks. Kava is also used to improve sleep, but there’s <a href="https://pubmed.ncbi.nlm.nih.gov/15700178/" target="_blank" rel="noreferrer noopener">limited research</a> that it’s even effective for treating insomnia.</p>
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<p><strong>Risks</strong>: While kava is sometimes promoted as a “safe” alternative to alcohol, it’s been associated with <a href="https://www.uclahealth.org/news/article/ask-the-doctors-what-are-the-risks-and-benefits-of-kava#:~:text=There%20are%20many%20reasons%20for,alcohol%20in%20addition%20to%20kava." target="_blank" rel="noreferrer noopener">liver toxicity</a>. In fact, in 2002, the <a href="https://ods.od.nih.gov/HealthInformation/kava.aspx#:~:text=The%20FDA%20reported%20that%20kava,adverse%20events%20in%20other%20countries." target="_blank" rel="noreferrer noopener">FDA issued an advisory</a> that kava supplements are linked to cirrhosis, hepatitis, and liver failure. This is mainly because <a href="https://www.uclahealth.org/news/article/ask-the-doctors-what-are-the-risks-and-benefits-of-kava#:~:text=There%20are%20many%20reasons%20for,alcohol%20in%20addition%20to%20kava." target="_blank" rel="noreferrer noopener">Kava has been found</a> to reduce glutathione, an important antioxidant that helps protect the liver, while also slowing the enzymes that break down harmful substances. For that reason, using kava and alcohol together is warned against as the combination can <a href="https://adf.org.au/drug-facts/kava/" target="_blank" rel="noreferrer noopener">greatly increase the risk</a> of liver damage.</p>
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<p>Even though kava is still readily sold as a dietary supplement, the FDA states that it is not <a href="https://www.fda.gov/food/generally-recognized-safe-gras/post-market-determinations-use-substance-not-gras?utm_source=chatgpt.com" target="_blank" rel="noreferrer noopener">generally recognized as safe (GRAS)</a>. <a href="https://www.cdph.ca.gov/Programs/CEH/DFDCS/CDPH%20Document%20Library/FDB/FoodSafetyProgram/KavaFactSheet.pdf" target="_blank" rel="noreferrer noopener">Other adverse effects</a> include vision impairment, rashes, nausea, and seizures.</p>
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<h3 class="wp-block-heading">Vitamin D</h3>
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<p><strong>What is it?</strong>: Vitamin D is an essential fat-soluble vitamin that’s <a href="https://medlineplus.gov/vitamind.html" target="_blank" rel="noreferrer noopener">available in foods</a> including eggs, seafood, and liver. It’s also a hormone produced naturally by our exposure to the sun. Available in supplement form, it’s one of the <a href="https://www.cdc.gov/nchs/data/nhsr/nhsr183.pdf" target="_blank" rel="noreferrer noopener">most widely used vitamins</a> in the United States, long believed to help support bone and heart health.</p>
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<p><strong>Benefits</strong>: While our bodies do need vitamin D to maintain strong bones, taking vitamin D in supplement form may not actually improve bone health. In 2024, the U.S. Preventive Services Task Force published a <a href="https://www.uspreventiveservicestaskforce.org/uspstf/draft-recommendation/vitamin-d-calcium-combined-supplementation-primary-prevention-falls-fractures-communitydwelling-adults" target="_blank" rel="noreferrer noopener">draft recommendation</a> stating that vitamin D supplements have no real benefit when it comes to the prevention of fractures in older adults.</p>
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<p>One potential benefit is improved immunity. “We have vitamin D receptors all over the body,” says Acerra, “and it does seem to be helpful for the immune system.” Indeed, studies have found that vitamin D may have protective effects against <a href="https://www.bmj.com/content/356/bmj.i6583" target="_blank" rel="noreferrer noopener">respiratory infections</a> in the general population (especially for those deficient in the vitamin) and <a href="https://www.sciencedirect.com/science/article/pii/S0002916523018324#:~:text=In%20conclusion%2C%20our%20study%20suggests,by%20vitamin%20D3%20supplementation." target="_blank" rel="noreferrer noopener">certain strains of the flu virus</a> in children.</p>
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<p><strong>Risks</strong>: In rare cases, taking excessively high doses of vitamin D (doses exceeding <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC6158375/" target="_blank" rel="noreferrer noopener">10,000 IU/day</a>), <a href="https://www.ncbi.nlm.nih.gov/books/NBK557876/" target="_blank" rel="noreferrer noopener">can be toxic</a>, with symptoms ranging from weakness and fatigue to cardiac arrhythmia and coma. For context, the recommended daily amount of vitamin D for the general public, ages one to 70, including pregnant and breastfeeding women, is <a href="https://ods.od.nih.gov/factsheets/VitaminD-Consumer/" target="_blank" rel="noreferrer noopener">600 IU/day</a>, according to the National Institutes of Health. In 2021, U.S. poison control centers reported more than <a href="https://piper.filecamp.com/uniq/foxfmW1ZMgxnjQTH.pdf" target="_blank" rel="noreferrer noopener">11,000 instances of vitamin D</a> toxicity, with the majority of cases being children 12 and under.</p>
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<p>An excess of vitamin D can also make the <a href="https://medlineplus.gov/ency/article/002405.htm" target="_blank" rel="noreferrer noopener">intestines absorb too much calcium</a>. This can lead to kidney stones, calcium deposits in the heart and lungs, weakness, and disorientation. If you do choose to supplement with vitamin D, some experts recommend a formulation that combines vitamin D with vitamin K2 to help avoid this issue. “Vitamin K2 can help by moving calcium out of the arteries and into the bones,” says Acerra.</p>
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<h2 class="wp-block-heading">Supplements and Medication Interactions</h2>
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<p>Most people who take supplements usually don’t consider them as serious or important as their prescription medications. This probably accounts for why some 75% of adults in this country <a href="https://www.aafp.org/pubs/afp/issues/2017/0715/p101.html" target="_blank" rel="noreferrer noopener">don’t think to disclose their supplement use</a> to their doctors. However, the <a href="https://www.fda.gov/consumers/consumer-updates/mixing-medications-and-dietary-supplements-can-endanger-your-health" target="_blank" rel="noreferrer noopener">FDA warns</a> that mixing certain supplements with a variety of medications can be dangerous.</p>
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<p>“It’s crucial to consult a healthcare provider before combining supplements with medications,” says <a href="https://www.instagram.com/nomadista_nutrition/" target="_blank" rel="noreferrer noopener">Mascha Davis</a>, a registered dietitian nutritionist and author of <em>Eat Your Vitamins</em>. Davis explains that even a simple calcium supplement, for example, can block antibiotic absorption, thereby reducing its ability to fight infection.</p>
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<h2 class="wp-block-heading">How to Find Quality Supplements</h2>
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<p>According to the <a href="https://ods.od.nih.gov/factsheets/WYNTK-Consumer/" target="_blank" rel="noreferrer noopener">National Institutes of Health (NIH)</a>, dietary supplements may be appropriate for those who don’t get sufficient nutrients from their diet. However, “the best way to ensure you are taking the correct supplements in an appropriate dose is to get bloodwork done and have your labs properly evaluated by a doctor or registered dietitian,” says Pelitera.</p>
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<p>If you do need a dietary supplement, Davis recommends discussing your options with a healthcare professional who can help you choose a high-quality option. In her practice, Davis looks for third-party-testing certifications, such as ConsumerLab, US Pharmacopeia (USP), and the National Science Foundation (NSF), all of which indicate that the product has been tested for potency and purity. She also examines the label to avoid supplement products with harmful additives or artificial dyes.</p>
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<p>While supplements can support health, they can also pose unexpected risks when taken incorrectly, which includes mixing with medications or taken in doses that are too high for what you need. Since supplements do not have the benefit of FDA oversight, it’s up to consumers to do their own research. Check for certifications, read up on the different brands, and most importantly, talk to a healthcare professional before randomly adding any supplement to your routine to make sure it’s right for you.</p>
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