How to read supplement labels: a plain-spoken guide
By Plum Supplements · 9 min read
To read a supplement label, skip the front and go to the Supplement Facts panel. Check the serving size first, then each ingredient's amount and % Daily Value, then whether any blend lists only a total weight. Finish with the other ingredients line, the warnings, and the manufacturer's contact details.
Why is the front of the bottle not enough?
The front of a supplement bottle is the brand's billboard. It is allowed to feature the most flattering number, use a large font, and lead with a benefit. The Supplement Facts panel on the back follows a standardized format required by the FDA, which makes it the one place you can compare two products on equal terms. Learning to read it takes about five minutes and pays off every time you shop.
What is a Supplement Facts panel?
It is the boxed table on the back or side of every dietary supplement sold in the United States. It always includes a serving size, servings per container, a list of dietary ingredients with amounts, and a % Daily Value where one has been established. Ingredients without a Daily Value are marked with an asterisk or the words "Daily Value not established."
| Section | What it tells you | What to check |
|---|---|---|
| Serving size | How many capsules, softgels, or gummies equal one dose | Is the advertised amount in one unit or several? |
| Servings per container | How long the bottle lasts | Use it to work out cost per serving |
| Amount per serving | The weight of each dietary ingredient | Look for the form in parentheses |
| % Daily Value | How the amount compares with daily reference intake | Very high percentages are worth a second look |
| Other ingredients | Capsule, fillers, flavors, colors | Allergens and anything you avoid |
What are serving size tricks?
The most common trick is not dishonest, it is just easy to miss. A bottle advertising "1,000 mg" on the front may require three or four capsules to reach it. Another variation is a 60 capsule bottle with a two capsule serving, which is a 30 day supply, not 60.
- Find the serving size at the top of the panel.
- Divide total capsules by the serving size to get the true number of servings.
- Divide the price by the number of servings for cost per serving.
- Compare products on that cost per serving, not price per bottle.
How do you read % Daily Value?
The Daily Value is a reference amount set by the FDA for nutrients like vitamins and minerals. The % DV shows how much of that reference one serving provides. 100 percent is not a target or a limit, it is a benchmark. Some nutrients, like biotin, are commonly sold at amounts far above 100 percent, which is why you will see figures in the thousands.
% DV is not the same as a safe upper limit. Some nutrients have tolerable upper intake levels set separately by the National Academies. If you take several products, add up overlapping nutrients.
What are proprietary blends?
A proprietary blend groups several ingredients under one name and lists a single total weight, with the ingredients in descending order by weight but without individual amounts. Brands use blends to protect a formula, but it means you cannot tell how much of any one ingredient you are getting.
We list each ingredient's amount wherever our labels allow. Where a product uses a blend, as our Probiotic does with its 375 mg probiotic blend and 100 mg prebiotic fiber blend, we show the total blend amount and every ingredient listed on the label, and we say plainly that per-ingredient amounts are not specified.
See how that looks on the Probiotic 40 Billion with Prebiotics page.
What does the "Other ingredients" line tell you?
Everything in the product that is not a listed dietary ingredient appears here: capsule shells like vegetable cellulose or gelatin, flow agents like rice flour or magnesium stearate, sweeteners and flavors in gummies, and antioxidants like mixed tocopherols in fish oil. These are usually unremarkable, but this is where to look for allergens, animal-derived ingredients, colors, and sugar.
What about claims and warnings?
Supplements may make structure/function claims, such as "supports relaxation," but they cannot claim to diagnose, treat, cure, or prevent a disease. Any structure/function claim must be accompanied by the FDA disclaimer. Warnings, such as advice to consult a physician if you take medication, are worth reading every time.
A quick checklist for any supplement label
- Serving size and true number of servings.
- Amount and form of each active ingredient.
- % Daily Value, and any overlap with other products you take.
- Blends: is each ingredient's amount listed?
- Other ingredients and allergens.
- Warnings and the FDA disclaimer.
- A manufacturer or distributor you can contact, and testing you can view.
Want to practice? Every Plum product page prints the full Supplement Facts panel, so you can read the label before you buy.
Frequently asked questions
What is the most important part of a supplement label?
The Supplement Facts panel, starting with the serving size. It tells you how many capsules make up the listed amounts, which changes how long a bottle lasts and what it really costs. Then check each ingredient's amount and form, any blends, and the other ingredients line.
What does % Daily Value mean on supplements?
It shows how much of an FDA reference amount one serving provides. 100 percent is a benchmark, not a requirement or a safety limit. Some ingredients have no Daily Value and are marked as not established. If you take several products, add up overlapping nutrients.
Are proprietary blends bad?
Not necessarily, but they tell you less. A proprietary blend lists a total weight and its ingredients in descending order, without individual amounts, so you cannot see exactly how much of each ingredient you get. Labels that list every amount are easier to evaluate.
What are other ingredients in supplements?
They are non-active components such as the capsule shell, flow agents like rice flour or magnesium stearate, flavors and sweeteners in gummies, and antioxidants in oils. They are usually minor, but this line is where you check for allergens, animal-derived ingredients, colors, and added sugar.
Why do supplement labels have an FDA disclaimer?
Federal rules require it whenever a supplement makes a structure/function claim, such as supports relaxation. It states that the FDA has not evaluated the claim and that the product is not intended to diagnose, treat, cure, or prevent any disease.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.