Evidence Level
Moderate
Alpha-lipoic acid has one of the longest clinical track records among longevity-adjacent supplements. The SYDNEY 2 trial (Ziegler et al., 2006) is the landmark study, a multicenter RCT demonstrating clear benefits for diabetic neuropathy at 600mg daily. Ansar et al. (2011) confirmed blood sugar benefits. Shay et al. (2009) published a comprehensive review establishing ALA's role as a mitochondrial cofactor and universal antioxidant. The R-enantiomer versus racemic debate is important — R-ALA is the naturally occurring, more potent form, and stabilized Na-R-ALA addresses the polymerization instability of pure R-ALA. ALA's ability to regenerate other antioxidants makes it a cornerstone of comprehensive antioxidant protocols.