Supplements reach shelves without FDA approval, but they are not unregulated — here is what the FDA and NIH say manufacturers actually have to do, before and after a product goes on sale.
Creatine is one of the few supplements with strong evidence behind it — for short-duration strength and power, in trained and untrained adults alike — and weaker evidence for the newer claims on its label frontier.
Synthetic stimulants and plant-derived beta-2 agonists keep appearing in supplements labeled as natural — and both sport and regulators treat them as prohibited or unlawful.
From a 2004 IOC-lab study finding undeclared prohormones in about 15 percent of samples to modern stimulant adulteration, contamination is documented, category-specific and manageable.
Recent pooled analyses put beta-alanine's benefit near 2.85 percent — concentrated in efforts lasting about one to ten minutes.
US rules require a proprietary blend to list its ingredients by weight order and its total weight — but not a single individual amount.