How to Read a Supplement Label (and Spot a Proprietary Blend)

The label tells you almost everything you need — if you know where to look. Here’s how to read a Supplement Facts panel and catch the trick most fat-burners use to hide their doses.

The single most useful skill in this category isn’t knowing which ingredient is trendy — it’s being able to read the Supplement Facts panel and tell whether you’re getting a real dose or a marketing sprinkle. It takes about two minutes once you know the parts.

Start with the serving size

Everything on the panel is “per serving,” and the serving is set by the manufacturer — not by you. Check how many servings you’re actually expected to take per day, and how many servings are in the container. A “30-day supply” at two scoops a day is really 15 days if you only take one. The serving size also quietly determines every dose below it.

Then the active ingredients and their amounts

Each active ingredient should be listed with an amount, usually in milligrams (mg) or grams (g). This is where you compare against what research actually uses. For example, our green tea extract page notes the EGCG doses studied for weight; if a product lists far less, expect a smaller effect. The same goes for glucomannan, berberine and others — the ingredient database gives the studied range for each.

The big one: spotting a proprietary blend

Here’s the trick to watch for. A proprietary blend lists several ingredients grouped under one name with a single total weight — for example “Metabolic Blend 550 mg” followed by a list of five ingredients. Crucially, it does not tell you how much of each ingredient is in that 550 mg. The first ingredient might be 500 mg and the rest “fairy dust” amounts — you have no way to know.

The rule of thumb is simple: a label that discloses every individual dose is telling you the truth about what you’re buying; a label that hides amounts inside a blend is asking you to trust it.

Don’t ignore the “other ingredients” line

Below the actives sits “Other Ingredients” — fillers, capsule material, flow agents, sweeteners and allergens. This is where you’ll spot things like gluten, soy, dairy or artificial sweeteners if those matter to you.

Put it together

A trustworthy label, in plain terms, has: a realistic serving size, every active ingredient listed with its own disclosed amount, doses in the ballpark of what research uses, and no critical ingredient buried in a blend. That’s exactly the standard our clarity score measures — and why two products with identical-looking ingredient lists can score very differently. When you’re ready to compare real labels side by side, our comparisons line them up for you.

Frequently asked questions