Being an informed supplement consumer starts with being able to decode what's actually on the label. The supplement industry has developed several labelling conventions that sound scientific but often obscure rather than clarify what you're actually getting. This guide teaches you to read labels critically.
The Supplement Facts Panel
Every supplement must display a Supplement Facts panel — analogous to the Nutrition Facts panel on food. Key elements: Serving size: All quantities listed are per serving. If the serving size is 3 capsules and you take 1, you're getting one-third of every listed amount. Servings per container: Divide the container size by serving size to understand how long it lasts. Daily Value %: Useful for vitamins/minerals but irrelevant for performance supplements (no DV exists for creatine or curcumin).
Proprietary Blends: The Biggest Red Flag
A proprietary blend lists a group of ingredients with a total combined weight but no individual ingredient quantities. Example: "Performance Matrix (L-Citrulline, Beta-Alanine, L-Arginine) 2400mg." You cannot determine if any ingredient is at an effective dose. L-Citrulline requires 6000mg for meaningful effect; if the entire blend is only 2400mg, it's impossible for L-Citrulline to be effectively dosed. Proprietary blends allow manufacturers to include trace amounts of popular ingredients while billing them as key components.
Reading Active vs Elemental Doses
For minerals, the form matters. "Magnesium glycinate 1000mg" contains only ~14% elemental magnesium — so the actual magnesium content is 140mg. Always look for the elemental amount listed in parentheses, or calculate it yourself based on the form's elemental percentage. Similarly, "curcumin extract (standardised to 95% curcuminoids)" means 95% of the listed weight is active — this is important for dosing calculations.
Third-Party Testing Seals
Look for: NSF Certified for Sport — gold standard, tests for 270+ banned substances plus label accuracy. Informed Sport / Informed Choice — similar rigour, used widely in UK and European markets. USP Verified — verifies ingredient identity and potency but does not test for WADA banned substances. GMP facility only — says nothing about the specific product's testing. No seal — relies entirely on manufacturer self-reporting.
