How to read a supplement label

Supplement labels carry more information than they look like they do, and most of it is in a small box on the back. Here is how to read one in about ninety seconds, so the next bottle you pick up makes sense in your hand.

Where is the Supplement Facts panel?

It lives on the back, and it is the regulated part of the bottle. Every real number is in there.

You are looking for three columns: the ingredient, the amount per serving, and the % Daily Value. Once you know where they sit, every label in the shop becomes readable.

Ingredient	Amount per serving	% Daily Value
Vitamin C, as ascorbic acid	180 mg	200%
Vitamin D3, as cholecalciferol	40 mcg	200%
Zinc, as zinc citrate	11 mg	100%

That is what the three columns look like filled in, taken from one of our own labels.

Why does the serving size come first?

This is the line that changes all the maths. A label might list an impressive amount of something per serving, and a serving might be four capsules. If the bottle holds 60, that is fifteen days rather than a month.

So do the arithmetic before you compare prices. Cost per serving is the number worth knowing, and it is rarely the number on the shelf edge.

How are the amounts listed?

Some labels give one combined number for a group of ingredients, listed as something like "Immune Complex, 500 mg". Ingredients inside a group are ordered by weight, so you get a hint about the ranking, but not the individual amounts.

Labels that print a milligram figure beside every single ingredient let you add up your day across everything you take, which is handy if you have a couple of bottles on the go.

How do you compare the dose to the research?

If an ingredient is famous for a particular study, it is worth knowing what dose that study used. A number in the same neighbourhood tells you the label is quoting the research properly.

This cuts both ways, and it applies to us too. We wrote about zinc lozenges and why our capsule is a different thing, because the doses in that research are much larger than an everyday nutritional amount.

Why read the form, not just the name?

"Zinc" is not a full specification. Zinc citrate, zinc oxide and zinc gluconate behave a little differently once they are inside you.

Same with B6, where pyridoxal 5'-phosphate is the active form your body can use directly and pyridoxine HCl gets converted first. Same with folate and magnesium. The form is printed in brackets, and it is one of the more useful things on the panel.

Where was it made?

Look for an actual address, plus the phrases "FDA-registered facility" and "GMP-certified". Not glamorous, genuinely worth having.

What is the front of the bottle for?

The front is where the nice design goes. The back is where the numbers go. Read the back, then admire the front.

Ours are all printed, on every product we make.

If you would rather not do the arithmetic by hand, the percent Daily Value calculator and the label reader both work from the same numbers the label uses.

FAQ

What is the most important line on a supplement label? The serving size. It changes every other number on the panel, including cost per day.

What does % Daily Value mean? How much of the official reference amount for that nutrient one serving provides. It is a reference point, not a personal target.

Why does the form of an ingredient matter? Different forms of the same nutrient, like zinc citrate versus zinc oxide, or P5P versus pyridoxine HCl, absorb and behave differently even at the same milligram amount.

What does it mean if a label lists a "blend" with one combined number? The individual ingredients inside are ordered by weight but not broken out with their own amounts, so you can see the ranking but not the exact split.

Sources

• FDA, Daily Value reference amounts for the Nutrition and Supplement Facts labels
• FDA, Dietary Supplement Labeling Guide

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.