Reading Labels

How to Read a Supplement Facts Panel

The panel is a legally structured document. Once you know what each part is required to tell you, the gaps become obvious.

Check serving size against servings per container, demand per-ingredient doses, and treat proprietary blends as missing information rather than a trade secret.

Serving size is where comparisons go wrong

Everything else on the panel is expressed per serving, so the serving size sets the scale for the whole document. A formula whose serving is two scoops looks identical on a per-serving basis to one whose serving is a single scoop, while costing twice as much per use and emptying the tub twice as fast.

Multiply out before comparing: servings per container times price per container gives cost per serving, and that is the only number worth putting side by side.

Proprietary blends are missing information

When ingredients appear under a named blend with a single total weight, the manufacturer is permitted to withhold the individual amounts. Ingredients within the blend must be listed in descending order by weight, which tells you the ranking and nothing about the magnitude.

This means a 5 g blend led by citrulline could contain 4.5 g of citrulline and traces of everything else, or 1 g of citrulline and a crowd of near-zero extras. Both are legal, and both print the same panel.

Treat a blend as information the label chose not to give you. Sometimes the reason is genuine formulation IP. More often, the disclosed version would be unflattering — because a brand with generous doses has every commercial incentive to print them.

What % Daily Value does and does not cover

Percent Daily Value compares the amount per serving to an established reference intake. It exists for vitamins and minerals, and it is genuinely useful for spotting a multivitamin delivering 2000% of something.

Many sports-nutrition ingredients — creatine, beta-alanine, citrulline — have no established Daily Value, so the column shows a dagger and a footnote. That is not a gap in the label; there is simply no reference figure to cite. Judge those ingredients against the research doses instead.

The regulatory baseline, stated plainly

In the United States, supplements are regulated as food rather than as drugs. Manufacturers are responsible for their own safety and labelling compliance, and there is no requirement to demonstrate efficacy to a regulator before selling a product. Enforcement is largely after the fact.

This is why third-party certification does real work. NSF Certified for Sport, Informed Sport and USP each verify that contents match the label and screen for contaminants and banned substances. None of them certifies that a product works — they certify that it contains what it claims to.

For anyone subject to drug testing, third-party certification is not optional diligence. Contamination of unverified supplements with undeclared substances is well documented, and the consequences land on the athlete.