How Much Melatonin Should You Take for Sleep?

How Melatonin Works in the Body

Melatonin is synthesized from tryptophan via serotonin in the pineal gland, with secretion gated by the suprachiasmatic nucleus (SCN). Endogenous levels begin rising about two hours before habitual bedtime, a marker known as Dim Light Melatonin Onset (DLMO). Plasma concentrations peak between 2 and 4 AM and return to baseline by mid-morning. When taken as a supplement, exogenous melatonin feeds back into MT1 and MT2 receptors in the SCN and downstream tissues, producing both a phase-shifting (chronobiotic) effect and a mild sleep-promoting effect. The phase shift is what matters for jet lag, shift work and Delayed Sleep-Wake Phase Disorder; the mild hypnotic effect is what helps with sleep-onset insomnia.

Low-Dose Therapeutic Range

Brzezinski et al. (Sleep Medicine Reviews, 2005) pooled 17 randomized controlled trials and showed that doses as low as 0.3-1 mg reliably reduce sleep onset latency by about 4 minutes and increase total sleep time by about 13 minutes. Higher doses (3-10 mg) do not produce a larger effect; they simply raise plasma melatonin to supraphysiological levels for longer, increasing next-day grogginess, vivid dreams and headache. The commercial US market sells 3, 5 and 10 mg gummies because consumers equate "more milligrams" with "more effective" — a misconception your clinician should correct.

Pediatric Dosing (Under Medical Supervision)

The American Academy of Pediatrics (AAP) 2021 health advisory recommends melatonin in children only with pediatrician oversight and only after sleep hygiene interventions have failed. Typical dosing: 1-3 mg in children under 6, only when behaviorally medically necessary. For autism spectrum disorder (ASD), the Malow 2012 pediatric protocol uses 1-3 mg starting 30 minutes before bed and titrating slowly; for ADHD-related sleep onset delay, Bendz & Scates (2010) reported benefit with 3-5 mg in older children. Critically: a CDC MMWR analysis showed pediatric melatonin ingestions reported to US poison control centers rose 530% between 2012 and 2021, with most cases involving unintentional gummy overdose in children under 5. Store melatonin like any other medication — out of reach, in a child-resistant container.

Adult and Older-Adult Dosing

For adults with sleep-onset insomnia, 0.5-3 mg of immediate-release melatonin 30-60 minutes before bed is the AASM-endorsed range. For older adults (65+), endogenous melatonin output declines, and sustained-release formulations (such as the EU-approved Circadin, not currently FDA-approved as a drug in the US) at 0.5-2 mg are preferred to mimic the natural nocturnal curve. The FDA has approved two melatonin receptor agonists by prescription: Ramelteon (Rozerem, 8 mg) for sleep-onset insomnia and Tasimelteon (Hetlioz, 20 mg) for Non-24-Hour Sleep-Wake Disorder — these are drugs, not supplements, and have a different regulatory and quality assurance profile than OTC melatonin.

Jet Lag and Shift Work Protocols

For eastbound travel crossing 5+ time zones, AASM recommends 0.5 mg taken 30 minutes before target local bedtime for 4-5 consecutive nights starting the day of arrival. Westbound jet lag is usually self-correcting within 2-3 days and melatonin offers little benefit. Shift workers — particularly permanent night-shift workers — can take 0.5-3 mg before their daytime sleep window to consolidate the sleep period, combined with morning blue-light blocking and bedroom blackout.

Drug Interactions and OTC Quality Concerns

Melatonin interacts with warfarin (potentiates anticoagulation), SSRIs (additive serotonergic effect), oral contraceptives (which inhibit melatonin metabolism via CYP1A2, raising effective plasma levels), antihypertensives (can blunt nocturnal BP dip) and immunosuppressants. Disclose melatonin use to your prescribing clinician.

Because the FDA regulates melatonin as a dietary supplement rather than a drug, manufacturers are not required to verify dose accuracy or screen for contaminants. ConsumerLab.com and US Pharmacopeia (USP) independently test and certify supplement brands; look for the USP Verified mark on the bottle. Avoid gummy formulations marketed to children unless directed by a pediatrician — they are the most common source of accidental pediatric overdose.

Side Effects and Safety

Common side effects at appropriate doses include headache, daytime sleepiness, vivid dreams and mild dizziness. Tolerance and physical dependence have not been demonstrated in short-term studies, but long-term (multi-year) safety data is limited, particularly in children. If you need melatonin nightly for more than 3-4 weeks without improvement, your sleep complaint is unlikely to be circadian — see a sleep medicine physician for a workup that may include actigraphy or polysomnography.