Amino acid l-lysine tested for hormone effects in healthy volunteers

This study looked at whether L-lysine, a common amino acid, changes levels of aldosterone and cortisol—hormones that control salt balance and stress. Twenty healthy men took L-lysine or a placebo for 13 days, then switched. Researchers measured hormone responses to standing, a drug, and a low-salt diet. The goal was to understand basic hormone control, not to treat any disease.