A product label gives you a compact way to compare what is inside a dietary supplement. Start with serving information at the top of the Supplement Facts panel: serving size and servings per container. Amounts listed below are tied to that serving, so compare products only after checking whether a serving is one capsule, several capsules, a scoop, or a packet.
Look at the ingredient and amount columns
Review the names of dietary ingredients and their amounts per serving. The U.S. Food and Drug Administration explains that Supplement Facts panels list serving size, servings per container, dietary ingredients, and ingredient amounts where required. Some nutrients also show a % Daily Value (%DV), a reference for how much one serving contributes to a daily diet.
Check % Daily Value in context
%DV can help you compare the amount in one serving with the established Daily Value. It is not a personal target or a measure of whether a product is right for you. Individual needs can depend on age, diet, health status, and medication use.
Read beyond the panel
Look for the other-ingredients list, serving directions, warnings, net quantity, and manufacturer or distributor contact information. If you have allergies, check the allergen statement on the actual package. Online information can be incomplete or may not reflect a later label update.
Keep questions for a qualified professional
If you use prescription or over-the-counter medicines, are pregnant or nursing, or have a health condition, discuss a supplement with a qualified healthcare professional before using it. The NIH Office of Dietary Supplements offers consumer fact sheets on ingredients and safety topics.
Sources: FDA: Questions and Answers on Dietary Supplements; FDA: Daily Value on Nutrition and Supplement Facts Labels; NIH ODS: Dietary Supplements—What You Need to Know.
This article is general information, not medical advice.