NSF Certified for Sport

NSF Certified for Sport is a third-party certification that verifies a product matches its label and screens for banned substances and contaminants, backed by facility audits. It is one of the most recognized marks in the supplement aisle and, like Informed Sport, costs the brand real money and invites inspection — which is exactly why publishing it is a signal worth weighting. When two products are otherwise close on the dollars-per-20g math, certification is a reasonable tiebreaker, and our reviews treat it that way.