6 Drugs That Can Cause Hair Loss

6 Drugs That Cause Hair Loss
6 Drugs That Cause Hair Loss
Emma Yasinski
Emma Yasinski Staff Writer
Last updated:

By the time Imali Chislett was diagnosed with ulcerative colitis, her hair had already been falling out for four months. It came out in clumps as she brushed her fingers through her hair, and when she tried to braid it. Soon, her scalp became sore, too. The illness, which affects the intestines, made it difficult for her to absorb nutrients from the food she was eating and she’d become severely iron deficient, which can cause hair loss. Unfortunately, treatment didn’t restore her strands. Since July 2023, she’s been receiving infusions of a powerful immunosuppressant drug, infliximab, which she says has lessened, but not stopped, her hair loss. She now wears a wig.

There are many reasons for hair loss. It’s common with the hormonal changes associated with aging, of course. Many men experience male-pattern hair loss (characterized by a receding hairline or thinning at the crown of the head) as they get older. Women also experience hair loss with age, which typically looks like thinning hair all over, and a widening part. Though it’s usually associated with middle age, hair loss can happen when you’re as young as in your 20s. The age at which you start losing your hair is often genetic; look to your parents for clues as to whether your hair loss is normal!

If your hair loss doesn’t follow the typical pattern associated with aging—for example if you’re losing small clumps of hair in an indistinguishable pattern—there could be many other reasons for it. Most causes are temporary or can be managed with treatment. Some of the reasons include:

  • Physical or emotional stress: Hair loss may follow a serious illness, or life stressor such as losing your job.
  • Pregnancy: Mothers may lose clumps of hair for up to a year after pregnancy.
  • Alopecia areata: an autoimmune disease.
  • Vitamin deficiencies: such as iron (like Chislett had) or vitamin D.
  • Thyroid disease or other hormonal conditions such as polycystic ovarian syndrome (PCOS.)
  • Side effects of medications

Is My Medicine Making My Hair Fall Out?

Hair growth and loss is a delicate process, and there are many ways it can be disrupted. Typically, adults shed about 50-100 hairs per day, but while we may notice those hairs in our drain, we usually don’t miss them on our heads because we’re always growing more hair to replace them.

However, medications can attack our hair follicles, causing more than usual to fall out. Medications can also send signals that slow the growth of new hair, making the hair we typically lose seem much more dramatic. If you suspect that your drugs could be causing hair loss, it’s important to speak with your healthcare provider. There may be alternative medications or other strategies to help replenish your locks.

Here’s how some common medications can cause hair loss.


It’s no secret that this common cancer treatment can cause baldness. It can take several months up to a year to even start growing your hair back after treatment. Chemotherapy is not a very targeted treatment; because cancer cells grow faster than many other cells in your body, chemotherapy is designed to fight any rapidly-growing cells. Unfortunately, the cells that make up your hair tend to grow pretty quickly and thus, chemotherapy sometimes weakens them too, so much that your hair breaks or falls out.

If you’re undergoing chemotherapy and concerned about hair loss, one option to limit the damage is wearing a cold cap on your head during treatments. This reduces the extent to which chemo infiltrates your hair.

Jo-Ann Messing, who has been treated for cancer twice, used the cold cap the second time. In the first instance, she lost her hair.

“It really is a horrendous experience to wake up in the middle of the night and look at yourself in the mirror and see no hair, no eyebrows,” she says.

Using the cap was worth it to lose less of her hair, she says. Still, she emphasized that the cold cap was not a quick, easy fix. The treatments take longer because you need to wear the cap for a while before and after, plus it can cool your whole body. You’ll need to bundle up in blankets.


Experts aren’t exactly sure how the drugs cause hair loss. It could be that they interfere with hormones such as melatonin, which tell your hair when to grow, when to stop, and when to fall out. One large study found bupropion is more likely to cause hair loss than other antidepressants.

Valproic Acid

Valproic Acid is an antiseizure drug that is sometimes prescribed for bipolar disorder and migraines. One study found that about 9% of people who used valproic acid reported experiencing hair loss.

The higher your dose, the more likely you are to experience hair loss. Experts recommend starting on a low dose and gradually increasing it to lower the likelihood of hair loss. One way that the drug causes hair loss may be through causing a deficiency in biotin. Taking biotin supplements may help you keep more hair, according to small studies in children and animals.

Weight Loss Drugs

In clinical trials of new weight loss drugs Wegovy and Zepbound, 3 to 6% of patients reported hair loss. However, experts suggest that this may not be related to the drugs themselves, but the fact that you’re rapidly losing weight.

There are lots of ways that weight loss, with or without medications, which can cause hair loss. Quick weight loss can stress your body, or excessive dieting can cause vitamin deficiencies that can weaken your hair. Researchers told NBC News that most people started growing their hair back shortly after their weight loss plateaued. Check out MedShadow’s Weight Loss Drug Side Effect Tracker for up to date information on these new treatments.


Methotrexate is an immunosuppressant, which dampens your immune activity to treat autoimmune conditions characterized by an overactive immune system, such as rheumatoid arthritis. However, it’s also a chemotherapeutic drug. It’s less likely to cause hair loss when it’s used in lower doses to treat autoimmune disorders than the higher doses typically required to treat cancer, because it’s used in lower doses, but it can still cause some hair loss.

In a small study on patients who were prescribed methotrexate to treat uveitis (eye inflammation), African Americans were more likely to experience hair loss than patients of other races (14% compared to 6.6%).


A large study found that 3.2 to 5.7% of patients who took isotretinoin capsules for acne experienced hair loss. Those on a dose higher than 0.5 milligrams were more likely to report the side effect of the medication than those who used a lower dose. The longer you take the drug, the more likely you are to lose some hair. Isotretinoin is derived from vitamin A, which is known to play a role in regulating your hair growth cycle.

Stay Informed About Side Effects

This is not an exhaustive list of every drug that can cause hair loss. If you’ve noticed more hairs in your sink or thinning spots on your scalp, and you think it may be a side effect of your medication, be sure to ask your healthcare provider. They may be able to recommend supplements, dietary adjustments, or alternative drugs so you don’t have to live with hair loss. When deciding on how to treat your hair loss, be cautious with medications, like Propecia, which may come with their own set of side effects.

DISCLAIMER: MedShadow provides information and resources related to medications, their effects, and potential side effects. However, it is important to note that we are not a substitute for professional medical advice, diagnosis, or treatment. The content on our site is intended for educational and informational purposes only. Individuals dealing with medical conditions or symptoms should seek guidance from a licensed healthcare professional, such as a physician or pharmacist, who can provide personalized medical advice tailored to their specific circumstances.

While we strive to ensure the accuracy and reliability of the information presented on MedShadow, we cannot guarantee its completeness or suitability for any particular individual's medical needs. Therefore, we strongly encourage users to consult with qualified healthcare professionals regarding any health-related concerns or decisions. By accessing and using MedShadow, you acknowledge and agree that the information provided on the site is not a substitute for professional medical advice and that you should always consult with a qualified healthcare provider for any medical concerns.

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