Sleep · Pineal indoleamine · OTC supplement / compounded
Melatonin: circadian signal and mitochondrial antioxidant.
Melatonin is the pineal hormone that signals 'night' to every cell in the body. Beyond sleep onset, it is one of the most potent endogenous antioxidants, concentrated in mitochondria where it scavenges free radicals at the source of ATP production. Production declines steeply with age — making physician-guided supplementation a foundational longevity move.
What Melatonin is
Melatonin (N-acetyl-5-methoxytryptamine) is an indoleamine hormone synthesized from serotonin in the pineal gland (and, in smaller amounts, in the gut, retina, and mitochondria).
Its release is governed by the suprachiasmatic nucleus (SCN) — rising after dark, peaking around 2–4am, and falling before dawn. This is the chemical signal that tells every cell in your body it is night.
Production drops significantly with age — the pineal gland calcifies and SCN output dampens. A 70-year-old typically produces a fraction of the melatonin they produced at 20. This decline correlates with sleep fragmentation, oxidative stress, and many age-related disease processes.
How it works
Melatonin binds MT1 and MT2 receptors in the SCN and across peripheral tissues, entraining the circadian clock and promoting sleep onset. MT1 suppresses SCN neuronal firing (sleep promotion); MT2 phase-shifts the clock (jet lag, shift work).
It also acts independently of receptors as a potent antioxidant — it crosses every membrane (including the mitochondrial inner membrane and blood-brain barrier) and directly neutralizes reactive oxygen species and reactive nitrogen species.
Crucially, melatonin is concentrated in mitochondria at levels far exceeding plasma — making it the body's primary mitochondrial antioxidant. This is the basis for the growing interest in higher-dose melatonin for longevity, neuroprotection, and metabolic disease.
What patients use it for
Sleep onset and maintenance
Low doses (0.3–3 mg) entrain circadian rhythm and reduce sleep latency. Higher doses do not work better for sleep specifically.
Jet lag and shift work
MT2 phase-shifting effect makes melatonin the best-studied intervention for circadian misalignment.
Mitochondrial antioxidant defense
Concentrated in mitochondria; directly neutralizes free radicals at the site of ATP production.
Anti-aging research signal
Mechanism overlap with mitochondrial decline and oxidative aging has placed melatonin at the center of multiple longevity-research programs.
Evidence summary
Auld F et al. (Sleep Med Rev, 2017) meta-analysis confirmed melatonin's effectiveness for primary insomnia, delayed sleep phase syndrome, and jet lag.
Reiter RJ et al. (Cellular and Molecular Life Sciences, 2017) reviewed melatonin's role as a mitochondrial antioxidant.
Karasek M (Exp Gerontol, 2004) — foundational review of age-related melatonin decline.
FDA Generally Recognized as Safe (GRAS) status for dietary use at standard doses provides long-standing safety data.
Dosing and clinical context
General clinical context only. Kindr Health physicians determine the appropriate dose and protocol for each patient based on history and labs. This is not a prescription or dosing recommendation.
Lower is better for sleep: 0.3–3 mg taken 30–60 minutes before bed is sufficient for circadian entrainment in most adults.
Higher doses (5–20 mg) are sometimes used for antioxidant / longevity protocols — these should be physician-supervised given the wakefulness paradox and morning grogginess risk.
Available OTC; compounded sustained-release and injectable forms are available under physician prescription.
Safety and contraindications
Very well tolerated. Most-reported: morning grogginess (especially at higher doses), vivid dreams, headache.
Theoretical caution: melatonin suppresses reproductive hormones (one of its non-sleep effects) — minimal practical concern at standard adult doses but documented at very high chronic doses in animal models.
Drug interactions: warfarin (mild INR effects), fluvoxamine (raises melatonin levels), immunosuppressants.
Contraindications: autoimmune disease (theoretical immune activation), pregnancy/lactation (insufficient data at supratherapeutic doses).
Who it's typically considered for
- Adults with delayed sleep phase, sleep fragmentation, or age-related sleep decline
- Travelers and shift workers managing circadian misalignment
- Longevity-oriented patients pursuing mitochondrial antioxidant protocols
- Adults titrating off Z-drugs or benzodiazepines for sleep
Frequently asked questions
How much melatonin should I take?
For sleep, start at 0.3–1 mg, 30–60 min before bed. Most adults do not need more. Higher doses (5–20 mg) are sometimes used for antioxidant purposes — discuss with your physician.
Will melatonin make me dependent?
No. Melatonin does not produce dependence or tolerance the way benzodiazepines or Z-drugs do.
Why does my melatonin make me groggy?
Usually a dose-too-high issue. Try the lowest dose that works — many people overshoot.
Melatonin and longevity?
Mechanistically compelling (mitochondrial antioxidant, circadian regulation, immune modulation). RCT evidence in healthy adults for longevity endpoints is limited but growing.
Is melatonin a hormone?
Yes — it is the pineal indoleamine hormone. In the U.S. it is sold OTC; in most of Europe it is prescription-only.
Can I take melatonin every night?
Yes — long-term use at standard doses has good safety data. Cycling is not necessary the way it is for some sleep medications.
Sources
- Auld F et al. Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders. Sleep Med Rev (2017). — pubmed.ncbi.nlm.nih.gov/27692973
- Reiter RJ et al. Melatonin as an antioxidant: under promises but over delivers. J Pineal Res (2016). — pubmed.ncbi.nlm.nih.gov/26514237
- Karasek M. Melatonin, human aging, and age-related diseases. Exp Gerontol (2004). — pubmed.ncbi.nlm.nih.gov/15582288
Considering Melatonin?
A Kindr Health physician reviews every longevity intake — peptides are prescribed only when medically indicated based on your history and labs. There is no charge for the initial review.
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Medically reviewed by Dr. Ana Lisa Carr, MD, MBA
Board-Certified Family Medicine Physician · Lead Provider / Medical Reviewer
NPI 1689841744 · Last reviewed: May 10, 2026
Last reviewed May 10, 2026. Compounded medications are prepared by FDA-registered 503A pharmacies and are not FDA-approved drug products. Prescriptions require a clinical evaluation; a Kindr Health physician determines eligibility. Not for use in pregnancy. This page provides educational information and is not medical advice.