N-(p-Coumaroyl) Serotonin, a polyphenol isolated from the seeds of safflower, exhibits antioxidant, cardioprotective effects after ischemia, and antitumor activity. It may improve vascular distensibility and reduce cardiovascular risk. N-(p-Coumaroyl) Serotonin ameliorates atherosclerosis and distensibility of the aortic wall in vivo, and is commonly used in atherosclerosis research.

5-Hydroxytryptophan (NSC-92523) is a metabolite of tryptophan and a direct precursor of serotonin. It is a substrate of aromatic amino acid decarboxylase and can be used to induce depression models.