How to Read Supplement Labels: 7 Checks Before You Buy

Read the serving size and the servings per container before anything else. A pre-workout that lists "2 scoops" as a serving and 40 scoops per tub is a 20-day product at the directed dose; a protein powder that lists 30 g of protein per "2 scoops" delivers 15 g per scoop. Every dose on the panel is per serving, so a serving-size trick rescales the whole label at once.

Compare each listed amount with the evidence-based dose: creatine 3 to 5 g, caffeine 3 to 6 mg per kg, beta-alanine 3.2 to 6.4 g per day, citrulline 3 g or more, protein 0.4 g per kg per feeding. A product can list a Tier 1 ingredient and still be useless if the number beside it is a fraction of the trial dose. The current C4 Original, for example, lists 1 g of creatine nitrate (about 0.7 g of creatine) against a 3 g minimum; our C4 ingredients audit walks through every line.

A blend lists a total weight and the ingredients in descending order, nothing more. The first ingredient could be almost the entire blend and the last a token milligram. Jagim's survey found an average of 8 blended ingredients per top-100 pre-workout; the original Jack3d hid five ingredients, including the stimulant DMAA, in a 4.2 g blend. If the manufacturer will not tell you the dose, treat the ingredient as absent for evidence purposes and decide whether the disclosed ingredients alone justify the price.

"Creatine" can be monohydrate (hundreds of trials) or nitrate, HCL and ethyl ester (a handful, and the ester performed worse). "Magnesium" can be glycinate (well absorbed) or oxide (mostly laxative). "Protein" can be whey isolate or a collagen blend that contributes no leucine. The form is printed in parentheses after the ingredient name; the research dose applies to the studied form, not to the family. Our creatine HCL vs monohydrate analysis is the worked example.

The "Other ingredients" line lists everything that is not an active: sweeteners, flavors, fillers, oils, emulsifiers, capsule shells. It is where you find the maltodextrin that turns a "lean" protein into a carbohydrate product, the sugar alcohols that explain digestive upset, and the fat replacer that makes a 150-calorie bar possible. The David protein bar review shows how much of a product's story sits on that one line.

Informed Choice, Informed Sport, NSF Certified for Sport and USP Verified are the seals that mean an independent laboratory tested the product or batch for contaminants and banned substances. They matter because contamination is real: Geyer's 634-sample study found undeclared steroids in 14.8 percent of supplements, and the IOC consensus statement treats certification as the minimum standard for athletes. Every genuine certifier maintains a searchable product database; a seal you cannot find there is a graphic, not a certification.

"Clinically dosed" has no legal definition. "Pharmaceutical grade" describes nothing about a food supplement. "Supports" and "promotes" are structure-function claims that by law must carry the disclaimer that the FDA has not evaluated them. And a plant-sounding name can be a synthetic stimulant: "geranium extract" was DMAA, and later products used other botanical aliases for amphetamine-like compounds that Cohen and colleagues identified in analytical studies. An ingredient you cannot find in a pharmacology reference is a reason to look harder, not to trust the label more.