Melatonin Research Guide: Circadian Neurohormone & Antioxidant
Melatonin is the pineal neurohormone that entrains circadian rhythm — and one of the most potent endogenous free-radical scavengers in the mammalian body.
What is Melatonin?
Melatonin is a lipophilic indoleamine hormone synthesized in pinealocytes from tryptophan via serotonin. Its plasma concentration follows a circadian rhythm entrained by retinal light input to the suprachiasmatic nucleus.
Mechanism of action
Receptor-mediated: MT1 and MT2 are GPCRs whose activation is linked to circadian phase-shifting, vasoconstriction, and immunomodulation.
Receptor-independent: melatonin directly quenches hydroxyl radicals, peroxynitrite, and singlet oxygen — one of the most potent endogenous free-radical scavengers characterized.
Sourcing & purity
Research-grade material should be ≥99% pure by HPLC with peptide content confirmed via mass spectrometry. Redline Bio material ships with batch documentation; independent third-party COAs are published on the lab reports page as testing returns.
Compliance reminder
Sold and distributed for laboratory research use only. Not approved by the FDA for human consumption, diagnosis, treatment, or cure of any disease. Researchers are responsible for compliance with all applicable institutional, state, and federal regulations.
Frequently asked questions
What is Melatonin?
Melatonin (N-acetyl-5-methoxytryptamine) is an indoleamine synthesized primarily in the pineal gland from tryptophan via serotonin. Its secretion is entrained to the light-dark cycle by the suprachiasmatic nucleus.
Mechanism?
Melatonin binds two G-protein-coupled receptors — MT1 (MTNR1A) and MT2 (MTNR1B) — that mediate circadian phase-shifting. It also acts as a potent direct antioxidant, scavenging hydroxyl radicals and peroxynitrite receptor-independently.