Reading a Supplement Label Without Getting Lost

Every legal dietary supplement sold in the United States must carry a Supplement Facts panel — the nutritional information box regulated by the FDA. It is distinct from a standard Nutrition Facts label found on food. Look for it on the back or side of the container. Everything else on the label — health claims, marketing language, imagery — is secondary to what this panel tells you.

At the top of the Supplement Facts panel, you will find the serving size — this might be one capsule, two tablets, one scoop, or something else entirely. Every number on the rest of the label corresponds to this amount, not the full bottle. Directly below, servings per container tells you how many doses you are actually getting. Multiply these two figures together to understand how long the product will last.

The body of the panel lists each ingredient, its amount per serving (in milligrams, micrograms, IU, or other units), and its % Daily Value (%DV) where applicable. The %DV reflects how much of a nutrient one serving provides relative to a general reference intake for a 2,000-calorie diet — a population-level baseline, not a personal prescription. Some nutrients, particularly herbal extracts, will show a dash (—) in the %DV column because no established daily reference value exists for them.

For a deeper look at how %DV works across packaged foods, see what the Nutrition Facts label is actually telling you.

Some products group multiple ingredients under a single proprietary blend name, listing only the total combined weight of the blend rather than individual amounts. While this practice is legal, it prevents you from knowing whether each component is present in a meaningful dose. Ingredients within a blend must still be listed in descending order by weight, so the first ingredient is the most abundant — but you still cannot tell by how much.

Below the Supplement Facts panel, manufacturers must list other ingredients — fillers, binders, coatings, colorants, and preservatives used in the manufacturing process. Common examples include cellulose (a plant-based capsule material), silicon dioxide (an anti-caking agent), and various dyes. If you have allergies, sensitivities, or dietary restrictions — for example, avoiding gelatin, gluten, or certain dyes — this section is essential reading.

Supplement labels may include one of several types of regulated claims. A structure/function claim — the most common type — describes how an ingredient may support a normal body function (e.g., 'supports immune health'). These claims do not require FDA approval, but the manufacturer must notify the FDA and include a disclaimer stating the claim has not been evaluated by the FDA and that the product is not intended to diagnose, treat, cure, or prevent any disease. Look for that disclaimer — its absence is a compliance problem. Be skeptical of language that sounds like a disease treatment claim, which is held to a much higher regulatory standard.

Because supplements are not pre-approved for safety or potency, independent organizations such as NSF International, the U.S. Pharmacopeia (USP), and ConsumerLab offer voluntary testing and certification programs. A seal from one of these organizations indicates the product was tested to verify that it contains what the label claims, in the stated amounts, and is free from specified contaminants. It does not confirm that the supplement will produce any particular health effect. For more guidance on evaluating supplement quality before purchasing, see our supplement safety checklist.