How to Read a Supplement Facts Label
Every dietary supplement sold in the US carries a Supplement Facts panel. It looks a lot like a Nutrition Facts label, but the lines mean slightly different things. Here's what each one actually tells you.
Serving size and servings per container
Everything below this line is measured per serving — not per capsule, tablet, or scoop, unless the serving size happens to be exactly one of those. A label that says "Serving Size: 2 Capsules" means the amounts listed apply to two capsules taken together, not one. Always check this before comparing two products' dosages side by side — a bottle with a "1 capsule" serving can look artificially cheaper per-dose than one with a "2 capsule" serving if you don't account for it.
"Servings Per Container" tells you how long a bottle actually lasts at the suggested use. Divide the capsule count by the serving size — a 60-capsule bottle at 2 capsules/day is a 30-day supply; the same 60-capsule bottle at 1 capsule/day is a 60-day supply.
%DV — and why it sometimes just says "**"
%DV (Percent Daily Value) shows how much of an established government reference amount one serving provides — this exists for vitamins, minerals, and a handful of other nutrients that have an official Daily Value set by the FDA. For a lot of botanical extracts and specialty ingredients, no such reference value exists at all. When you see a double asterisk (**) with a footnote reading "Daily Value not established," that's not a red flag by itself — it just means nobody has set an official reference amount for that ingredient. It's common, and it applies to most herbal ingredients you'll see across supplement labels generally.
Proprietary blends
Some labels group several ingredients under one heading — like "Proprietary Blend" or "Herbal Blend" — with a single combined weight instead of a separate amount for each ingredient. This is legal and common, but it means you can't tell exactly how much of any one ingredient in that blend you're getting. We've written a separate guide specifically on understanding proprietary blends if you want the full picture.
Other ingredients
Below the main table, "Other Ingredients" lists everything that isn't an active ingredient — things like the capsule shell material (often gelatin or a vegetarian alternative), anti-caking agents like silicon dioxide, or flavoring. These aren't dosed for effect; they're structural or functional parts of the product itself. Worth a glance if you have a specific sensitivity (gelatin, for example, isn't vegan).
What's not on the label
A compliant label tells you what's in the product and how much (or, for blends, how much of the blend as a whole). It won't tell you whether the product works for you personally — that's not what it's for. Manufacturer name, address, and country of origin are also required and usually printed near the bottom of the label, separate from the ingredient table itself.