Proprietary Blends: Supplements with Hidden Risks

Proprietary Blends: Supplements with Hidden Risks
Proprietary Blends: Supplements with Hidden Risks

As a breast cancer survivor with a neurological disease, Catherine Moriarty takes a single-ingredient pill for vitamin D, another for iron, and a multivitamin – all with clear labeling.

“I’m interested in stuff with anti-inflammatory properties. I only buy products with full disclosure of ingredients,” she says. “ It’s important to know what I’m putting into my body and so that I have the ability to gauge my response to different ingredients. I don’t ever buy or use products unless I have a full understanding of what they are.”

Supplements that have a mixture of ingredients are called proprietary blends — which are not required to list all the ingredients or the amounts of what vitamins and supplements are in the mixture. Moriarty won’t buy proprietary blends.

“It makes me not trust the product or the company,” said the 42-year-old Northampton, Massachusetts mother of a 7-year-old son. “It seems like it’s a way for companies to dodge telling you exactly what is in there,” she said.

“It’s ridiculous, “ said Nancy Dell, a registered dietician nutritionist in Feeding Hills, Massachusetts. “Anyone could make a proprietary blend,” she said. “They’re supposed to list the ingredients in order, most to least, but they don’t always do that. It’s like buying a can of nuts. It says mixed nuts and it’s mostly peanuts.”

She said they might be effective but not safe. For example, there might be stimulants in the blend, but not listed on the label could raise a person’s blood pressure or interact with other medications.

Also, she said, they can be expensive, and, “that might be dangerous for your pocketbook.”

She mostly sees these problems in anti-inflammatories, fitness products such as those intended to build muscle, anti-aging or weight-loss products. 

Proprietary Blends Can Hide Ingredient Amounts

According to, “The major problem with ‘proprietary formulas,’ as well as with proprietary ‘blends’ and ‘complexes,’ is that they permit manufacturers to withhold important information about what’s really in a product. Furthermore, the formula may change over time without you necessarily knowing.”

The FDA states that manufacturers of supplements (and food) must list the names and quantities of dietary ingredients present in the product, the “serving size” and the “servings per container.” But companies that label their products “proprietary blend” only have to list the total amount of the formulation, not the amount of each. The FDA’s code of regulations requires that “Dietary ingredients contained in the proprietary blend shall be declared in descending order of predominance by weight, in a column or linear fashion, and indented under the term ‘Proprietary Blend’ or other appropriately descriptive term or fanciful name.”

Paul Claybrook, a certified nutritionist in Kennewick, Washington, explained in an email, “When a product has a proprietary blend, it essentially means that they won’t tell you how much of each ingredient is in it in order to protect their ‘formula’ and/or for marketing purposes.  If they were forced to list the exact amounts of each ingredient, copycats could simply make the same product. 

“Sometimes particular ratios of ingredients make for better products. For example, one ‘proprietary blend’ of several ingredients in one energy drink may prove more effective than the exact same ingredients, but in different quantities, in another.

“The downside for the consumer, of course, is that we don’t know exactly what we are getting.”

Chicago-based Registered Dietitian Amanda A. Kostro Miller noted, “Unfortunately most over-the-counter products like supplements are not tightly regulated by the FDA. So, this can call into question the potency and concentration. Also, there tends to be a lack of substantial evidence pertaining to a supplement’s blend of ingredients.”

But Lana Dvorkin Camiel, professor and director of the Center for Drug Information and Natural Products at the Massachusetts College of Pharmacy and Health Sciences, is not against proprietary blends as a rule. “It’s about the reputation of the company,” she said. “Going with a good company is more important than avoiding proprietary blends. Highly responsible companies will not mess with things.”

She understands why companies make proprietary blends. While drug companies can test and patent a product, those using natural products cannot, “because mother nature does not allow a company to patent the product.”

When looking at these labels, the consumers can get some idea by choosing based on what is highest and lowest; for example, she said, if a product has caffeine and you want less of it, you would look for a product that has it at the bottom of the list. 

Beth Lambert, CEO of Herbalist and Alchemist, in Washington, New Jersey, said that proprietary blends made by a trusted manufacturer can lead to better results and “formulas targeted more to specific conditions.”

She said, however, that some companies concoct a “kitchen sink” formula that does not make sense and does not work well. Examples include: “Too many over-stimulating herbs in a formula for long-term use, and herbs that are not tonics (e.g. goldenseal, celandine) included in a tonic formula.”

But, she said, “There really aren’t many downsides to a well-crafted formula. Most systems of Traditional Medicine use herbs in formulas. It is the choice of herbs and how they work together that can really make it effective…We must disclose ingredients, but not disclosing the amounts is the only protection given to the intellectual property of a formulator.”