Figure 1From: The acute effect of beta-guanidinopropionic acid versus creatine or placebo in healthy men (ABC Trial): study protocol for a randomized controlled trialStructural analogy between creatine and beta-guanidinopropionic acid. Legend: Creatine (a) and beta-guanidinopropionic acid (b) have an identical molecular formula (C4H9N3O2), but creatine is methylated on its tertiary nitrogen, while in beta-guanidinopropionic acid, the methyl group is positioned in the carbon chain [16].Back to article page