Supplement Label Decoder

Paste the Supplement Facts panel from any brand. We check every ingredient against the amounts used in published human research and the official safe upper limits, and flag doses hidden inside proprietary blends. It runs in your browser — nothing you paste leaves your device.

How to read a supplement label in 60 seconds

1. Find the amount of each active ingredient. A transparent label gives a number in mg, g, or mcg next to every ingredient. If several ingredients share one weight under a “blend,” “matrix,” or “complex,” the individual doses are hidden.

2. Compare each amount with the research. Most ingredients only show effects in studies at a particular dose — creatine at about 3–5 g a day, for example. A pre-workout with 1 g of beta-alanine looks good on the front of the tub and does far less than the 3.2–6.4 g used in trials.

3. Check the upper limits. More is not better for vitamins and minerals. Vitamin B6 above 100 mg a day, niacin above 35 mg from supplements, and zinc above 40 mg are past the official upper limits for adults.

4. Add up the stimulants. Caffeine hides under many names (anhydrous, di-caffeine malate, green coffee, guarana, green tea). Add every product you take in a day.

Ingredient reference

The amounts studied in human research and official upper limits for the ingredients the decoder knows, with the source for each. Grades describe how consistent the human evidence is: strong (consistent reviews), moderate (several mostly positive trials), limited (few, small, or mixed trials), weak (mostly negative or animal-only).

Questions

What does “proprietary blend” mean on a supplement label?

A proprietary blend lists several ingredients under one combined weight without saying how much of each is inside. It's legal, but you can't tell whether any single ingredient is present at the amount used in research — a blend of 1,000 mg could be almost entirely the cheapest ingredient.

What is an upper limit (UL)?

The Tolerable Upper Intake Level is the most of a nutrient most healthy adults can take every day without a likely risk of harm, set by the National Academies and published by the NIH Office of Dietary Supplements. Some ULs apply only to supplements and fortified foods (for example magnesium, folic acid, and niacin).

How much caffeine is too much?

The FDA says up to 400 mg a day is generally not associated with negative effects in healthy adults. Sensitivity varies, and pregnancy, heart conditions, and some medications change that number — check every product you take, since caffeine adds up across pre-workouts, fat burners, and coffee.

Is “more than studied amounts” dangerous?

Not necessarily. It means the dose is higher than what published trials used, so there's less evidence about benefit or tolerance at that level. Compare it with the upper limit, and ask your doctor if you're unsure.

Do you store what I paste?

No. The decoder runs entirely in your browser; nothing you paste is sent to a server. A shared results link carries the label text in the part of the address after “#”, which browsers don't send to websites.

How this works

Every number comes from a public source we link to: NIH Office of Dietary Supplements fact sheets, FDA guidance, International Society of Sports Nutrition position stands, and systematic reviews indexed in PubMed. The decoder compares the amount on the label (times your servings a day) with the range used in human trials and with the adult upper limit. It does not judge product quality, purity, or whether a supplement is right for you. Last reviewed 2026-10-23.

This tool provides general information from published research and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Supplements are not intended to diagnose, treat, cure, or prevent any disease. Talk with your doctor or pharmacist before starting a supplement, especially if you are pregnant or nursing, take medication, or have a medical condition.