Trying to decipher supplement facts and information on vitamin labels can be complicated. Manufacturers have to pack unfamiliar abbreviations, acronyms, and seals of approval on small labels to provide as much information as possible about different, complex products. That’s why we’ve put together a quick guide about U.S. supplement labels that answers all the questions we could think of.

blonde woman holding two supplement bottles smiling

Have confidence in the supplements you recommend, by understanding supplement labels.

Dietary supplement regulations

In the US, The Food & Drug Administration (FDA) regulates and provides supplement fact and label guidelines (1).

Supplement facts vs nutritional facts

There are no established daily values for supplements. The FDA oversees both traditional foods and dietary supplements. Each falls into a separate category and have different label requirements (2). The difference isn’t obvious. Items like protein bars or green tea appear in both groups. Dietary supplements have nutritional labeling in the form of “supplement facts” panel, which lays out all the ingredients found in a supplement, but supplements do not have any established daily values due to lack of research and testing.

On supplement labels, ingredients are listed in descending order by weight.

What is serving size?

This is the recommended amount to take. Keep in mind since there are no established daily values for most of what you find in some supplements, you are putting your faith in the supplement company to suggest an appropriate serving size. Theoretically, the company should conduct its own testing on ingredients, but the FDA is not in charge of giving formal approval for any research. Just remember that supplement serving sizes are estimations, so it’s always a good idea to talk to your doctor about what the best serving size is for you.

What’s the amount per serving?

Most often broken down by Milligrams (mg) or Micrograms (mcg). Amount per serving allows you to evaluate the potency of particular ingredients, and see how much of a critical element there really is. For example, at the top of a multivitamin supplement, you will see an amount per serving shown. And then below the serving, you can see the multivitamin broken down into different nutritional components such as iron.

What is the percent daily value and DV?

A guide to the nutrients found in one serving. The Breakdown: Percent Daily value, known as DV for short, is set according to the Dietary Reference Intakes (DRIs) (3), which are set by The Food and Board of the Institute of Medicine of the National Academy of Sciences (4). For example, if the label lists 20 percent for magnesium, it means that one serving provides 20 percent of the magnesium you need each day. DVs are based on 2,000-calorie diets. Remember, its always a good idea to scale your requirements based on your calorie intake to meet your personal health goals.

What is ‘standardized’?

Look for this when taking herbal supplements. A standardized herbal supplement has extracts of herbs that have been chemically tested and confirmed to contain a minimum dosage of all known active constituents of the given herb. Standardized herbs normally go through an intricate process to manufacture, and the extracts must be analyzed. With non-standardized herbs, on the other hand, there is no way to determine their actual potency. The herb is used as-is without modification.

person holding supplement bottle

There is no way to guarantee the potency of a herb that is not standardized and packaged.

What is a proprietary blend?

A mix of several ingredients are present in a supplement, but there are no exact numbers. According to the FDA, this means that the manufacturer has combined several ingredients into a special blend. The ingredients are listed, and in order of the amount the product contains, but the manufacturer doesn’t need to say how much of each element is found. Consumer Reports (5) recommends consumers be wary of proprietary blends since they can contain a dangerous amount of certain ingredients.

What are calories and empty calories?

Calories are a measurement of how much energy you get from a serving of a supplement. When supplements have empty calories, it means they have very few vitamins or minerals, phytochemicals, or little fiber.

Possible Allergens

You will find a possible allergen(s) listed under ‘additional ingredients’, ‘other ingredients’, or ‘contains.’ The Food Allergen Labeling and Consumer Protection Act (FALCPA) requires that products labeled for supplements one or more eight major food allergens must explicitly state the presence of the allergen(s). The FDA further requires that a product passes several lab-based tests to substantiate any allergen-free claims.

What are excipients?

Excipients are another term for additional ingredients. An excipient is an element, other than the active ingredients found in a supplement or drug. The formulation of many supplements actually requires the combination of active ingredients with some additional non-dietary ingredients during the manufacturing process (6) in order to create the finished product. For example, starch is often used (7) as an excipient for extended-release tablets. You can see a list of examples of excipients and their functions here.

Storage and expiration date

Not all supplements have expiration dates, but some do. The FDA’s Good Manufacturing Practices doesn’t require expiration dates on supplement labels, but if there is one, that is because the company has decided to put it there. To be able to set an expiration date, the company must provide supporting data on the stability of supplement ingredients in various environmental conditions over time to the FDA.

The supplement industry has an estimated 90,000 plus products on the market.

What are FDA approved facilities

The FDA doesn’t ‘approve’ facilities. Having an ‘FDA Approved facility’ does not mean much. This is because the FDA as an organization does not ‘approve’ facilities that produce supplements and vitamins. The FDA provides guidelines for how manufacturers should do things, such as, preventing cross-contamination and maintaining a sanitary workspace. The FDA as an agency inspects just a handful of manufacturers, and there’s no official seal in place guaranteeing that rules have been followed.

What does ‘USP verified’ mean?

The U.S. Pharmacopeia (USP),, and NSF International are organizations known for certifying products. Seals from organizations such as the three listed above don’t guarantee value or test every batch of supplements from manufacturers but are a sign that the product most likely contains the amount of the ingredients listed on the label. More importantly, it means the product is not contaminated with dangerous substances, such as bacteria, arsenic, or lead. According to Consumer Reports (8), companies producing supplements must pay to get supplements tested and certified, which is why only a small amount of the dietary supplements on the market carry the seals.

Looking for disclaimers

“This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.” Supplements can make claims on labels such as “supports metabolism or boosts energy,” but don’t need to provide any evidence for claims related to their products’ ability to improve bodily structure or function. The statement quoted above is required by the Dietary Supplement Health Education Act of 1994 (DSHEA) (9) on any products that make claims about how their product affects the function or bodily structure. In other words, this statement means the claims you often see haven’t been approved by the FDA.

patient and practitioner explaining supplement bottle

It’s always a good idea to talk to your physician about the dosage of a supplement.

Further education

We’ve put together a list of trusted supplement resources that may be helpful. You can also always visit the FDA website by searching (10) their Supplement Labeling Guide: Nutrition Labeling if you are looking for further information.

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