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Sleep / Circadian

Melatonin · Melatonin

The circadian rhythm hormone; low doses (0.3 to 1 mg) work best.

A
Evidence grade
Replicated human RCTs with hard endpoints
Strongest study
Tier 2 · 2 linked studies

Short answer

Take much less than the label suggests. US 5 mg tablets are massive overdoses; European Rx melatonin is 0.5 to 2 mg.

Product and dose overview

Melatonin (Melatonin) is a sleep / circadian with evidence grade A, meaning it is well-supported by replicated human trials. We track 1 products containing Melatonin. Typical doses range from 0.5 to 0.5 mg per serving. The top-ranked product scores 5.3 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $34.99 per month.

Evidence grade: A Products in database: 1 Category: Sleep / Circadian

Top Melatonin products

ProductBrandDosePrice/mo3rd-party testedScore
Seed PM-02 Sleep + RestoreSeed Health0.5 mg$34.99Yes5.3

Scores are editorial judgments, not a scientific standard. See how we score.

What it is

A hormone your pineal gland makes at night to signal 'time to sleep'. Levels drop with age.

Why people take it

0.3 to 1 mg 30 min before bed reliably helps with sleep onset and jet lag. Higher doses (5 to 10 mg) often make sleep worse and cause morning grogginess.

Our verdict

Take much less than the label suggests. US 5 mg tablets are massive overdoses; European Rx melatonin is 0.5 to 2 mg.

Structure & class

N-acetyl-5-methoxytryptamine. Pineal indoleamine.

Mechanism & clinical data

Meta-analyses confirm improvement in sleep onset latency (Ferracioli-Oda 2013). Higher doses (>3 mg) cause supraphysiological plasma levels linked to next-day dysphoria.

Pharmacokinetics

~40 min immediate release; longer with prolonged release.

Dose & forms

Trial dose
0.5 mg
/ day
Range in trials
0.3 to 2 mg
/ day
Common forms
Sublingual (fast onset), Prolonged release (Circadin®), Standard tablet

What to watch out for

Rx in EU, OTC in US. US dietary-supplement melatonin is often mislabeled by 3 to 4× the stated dose (2017 audit).

Safety limits and interactions

When a product exceeds the UL or contains an ingredient with clinically significant interactions, a "Review advised" flag appears on its product page and links here.

Known drug interactions
Metabolized by CYP1A2 — caution with potent CYP1A2 inhibitors (e.g., fluvoxamine). Increases sedation when combined with benzodiazepines, zolpidem, or eszopiclone. May increase prothrombin time/INR with warfarin (case reports of increased bleeding). Can reduce effectiveness of extended-release nifedipine and immunosuppressants used after organ transplant.
Safety note
No formal UL; maximum dose has not been defined in trials, though EFSA and the American Academy of Sleep Medicine recommend maximum doses of 1 mg and 2 mg respectively. Considered relatively safe, but higher doses (>10 mg/day) increase minor adverse effects such as drowsiness, headache, and dizziness.

Source: https://www.ncbi.nlm.nih.gov/books/NBK534823/

Where this dose comes from

The trial dose above is our editorial pick from the published human trials for this ingredient. We choose the dose that the best-available studies used on the endpoint most relevant to longevity. The range shows the lowest and highest doses tested in published trials. The landmark studies below are the papers we read to set it. You can click through and check our work.

When new trials publish, our automated sweeps flag them. If a new study materially changes the dose, we update it through editorial review and record the old dose, new dose, and the triggering study in every affected product's recommendation history. The dose is never changed automatically.

Regulatory status

EUPrescription drug ≥2 mg; food supplement 0.5 to 1.9 mg
USDietary supplement
UKPrescription drug
CANHP

Timeline

Regulatory events, evidence grade changes, and key research milestones for Melatonin, most recent first. Studies link to the paper; regulatory entries name and link the responsible authority.

  • 2025-06 Regulatory confirmed
    EU classifies melatonin as prescription drug at doses >=2 mg
    In the EU, melatonin is classified as a prescription drug at doses of 2 mg or higher. Lower doses (0.5 to 1.9 mg) remain available as food supplements. The UK treats melatonin as a prescription drug entirely. The US allows melatonin as a dietary supplement without a prescription.
    Source →
  • 2025-04 Regulatory single source
    EU Court sharpens the bar for botanical health claims
    A Court of Justice of the European Union ruling in April 2025 further tightened the requirements for how botanical ingredients (herbs, plant extracts) can be marketed with health claims in the EU, effectively removing much of the flexibility of the on-hold list.
  • 2024-06 Regulatory confirmed
    EU heads of food safety agencies prioritize melatonin for restriction
    The HoA Working Group on Food Supplements identified melatonin among 12 substances prioritized for Article 8 restriction. French and Norwegian national risk assessments raised concerns about headaches, dizziness, drowsiness, and cardiovascular, neurological, digestive and psychological symptoms at supplement doses.
    Source →
  • 2024-06 Regulatory confirmed
    EU report identifies 117 supplement substances as potential health risks
    The HoA Working Group on Food Supplements (26 European countries) published its first report evaluating 117 substances used in food supplements. Of these, 65 were assessed as likely novel foods, 6 were already regulated, 34 had insufficient data, and 12 were prioritized for Article 8 restriction under Regulation (EC) No 1925/2006. The 12 priority substances include ashwagandha, curcumin, melatonin, piperine, St. John's wort, coumarin, p-synephrine, maca, holy basil, Melaleuca, black cohosh, and L-tryptophan. The report drew on 1,500 RASFF alerts reviewed between 2017 and mid-2022.
    Source →
  • 2024 Research milestone
    HoA 2024 (BVL/NVWA, EU)
    26-country EU working group prioritized melatonin for Article 8 restriction. French and Norwegian risk assessments raised concerns about headaches, dizziness, drowsiness, and cardiovascular, neurological, digestive and psychological symptoms.
    Source →
  • 2013 Research milestone
    Ferracioli-Oda 2013 (PLOS ONE)
    Meta-analysis: melatonin reduces sleep onset latency and improves total sleep time.
    Source →
  • 2006-12 Regulatory confirmed
    EU Health Claims Regulation adopted
    Regulation (EC) No 1924/2006 laid down harmonised rules for nutrition and health claims made on foods, including supplements. Only claims listed in the EU Register of authorised claims can be used. Rejected botanical claims are held in a separate on-hold list.
    Source →
  • 1997 Regulatory confirmed
    EU introduces the Novel Food Regulation
    Regulation (EC) No 258/97 required any food or food ingredient without a history of consumption in the EU before 15 May 1997 to be authorised before being placed on the market. This is the framework that captures NMN, spermidine as a supplement ingredient, urolithin A, and many other longevity actives.
    Source →
2026 evidence refresh

Melatonin modestly shortens sleep onset in RCTs, but a 2025 observational study linking long-term nightly use to nearly double the risk of heart failure and death has raised new questions marketing has not addressed.

Verified 2026-07-12. We update this section as new peer-reviewed trials land.

Human RCT base
25
peer-reviewed randomised trials
Largest single trial
n = 1683
A meta-analysis of RCTs found melatonin significantly reduced sleep onset latency and increased total sleep time versus placebo, with modest effect sizes in adults with primary sleep complaints. source

Best-supported claim

Melatonin's most established human benefit is a modest reduction in the time it takes to fall asleep. Ferracioli-Oda et al.'s meta-analysis of randomized controlled trials found melatonin significantly reduced sleep onset latency by about 7 minutes and increased total sleep time versus placebo in adults with primary sleep disorders (https://pubmed.ncbi.nlm.nih.gov/23691095/). It is also well established for treating jet lag and shift-work-related circadian misalignment, with Cochrane-reviewed trials showing benefit when timed correctly relative to the target sleep window.

Not supported by the evidence base

Melatonin is marketed as a harmless nightly sleep aid, but a 2025 American Heart Association-presented observational study following patients using melatonin for at least a year found those with chronic insomnia who used melatonin long-term had nearly double the risk of new-onset heart failure (hazard ratio 1.90) and more than double the risk of death from any cause (hazard ratio 2.06) compared to non-users, even after adjustment for other factors (https://newsroom.heart.org/news/melatonin-may-be-tied-to-increased-risk-of-heart-failure-death). This is observational data, not a randomized trial, so it cannot prove melatonin causes these outcomes, but it directly contradicts marketing framing melatonin as risk-free for long-term nightly use, and the finding has not yet been addressed by most supplement sellers.

Typical dose

0.5-5 mg/day taken 30-60 minutes before bedtime, or lower doses (0.3-1 mg) for jet lag and circadian adjustment

Safety

Melatonin is well tolerated in short-term RCTs, with drowsiness, headache, dizziness, and mild nausea as the most common side effects (https://pubmed.ncbi.nlm.nih.gov/23691095/). The 2025 observational data linking long-term (12+ months) nightly use to increased heart failure and mortality risk has not been confirmed by randomized trials, but given the scale of the finding, people with existing cardiovascular disease should discuss long-term nightly use with a physician rather than assuming it is risk-free (https://newsroom.heart.org/news/melatonin-may-be-tied-to-increased-risk-of-heart-failure-death). Children, pregnant or breastfeeding people, and those with autoimmune conditions should use melatonin only under medical guidance given limited long-term safety data in these groups.

Interactions worth flagging

  • Can enhance sedative effects of benzodiazepines and other sleep medications, increasing drowsiness risk
  • May increase bleeding risk when combined with anticoagulants like warfarin
  • Can reduce the effectiveness of immunosuppressant drugs due to melatonin's immune-stimulating properties
  • May interact with blood pressure medications, altering their effect

Three recent studies to know

  • Melatonin use and risk of incident heart failure and all-cause mortality in adults with chronic insomnia
    Presented at American Heart Association Scientific Sessions / American Heart Association Newsroom 2025 · n = n/a

    Long-term (12+ months) melatonin use in adults with chronic insomnia was associated with nearly double the risk of incident heart failure and more than double the risk of all-cause mortality compared to non-users, in an observational cohort.

    Read study →
  • Melatonin for sleep and cognitive outcomes in older adults with cognitive impairment: a meta-analysis of randomised controlled trials
    Age and Ageing 2025 · n = 516

    Meta-analysis of 10 RCTs in older adults with cognitive impairment found melatonin increased total sleep time by 12.4 minutes and modestly improved MMSE scores, though effects fell short of definitive clinical significance.

    Read study →
  • A Pilot Randomised Controlled Trial of Sublingual Melatonin for Sleep Onset Delay in Children with Foetal Alcohol Spectrum Disorder
    Journal of paediatrics and child health 2025 · n = 8

    A small pilot crossover trial in children with or at risk of foetal alcohol spectrum disorder found sublingual melatonin significantly reduced sleep onset latency and bedtime resistance versus placebo, with no serious adverse events.

    Read study →

Landmark studies

Found in these products (1)

All products in our catalog that contain Melatonin, ranked by our overall score. Ranking is editorial, never paid.

Autophagy
Ingredients listed
6 ingredients listedlargest listed: Probiotics 200 mg
Price per serving
$1.17$34.99 · 30 servings
Testing
3rd-party listed · no public lab certificate

CFU not stored

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 5.3/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

1%
of trial dose
$358.87
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with seed.com
Editorial guides

Buying guides and comparisons

Neighbouring molecules

Related ingredients

See all in Sleep / Circadian →

Molecules in the same class, plus the actives most often formulated alongside Melatonin in our catalogue.

GABADsame categoryRiboflavin (B2)Bstacked together in 1 productPQQCstacked together in 1 productPterostilbeneDstacked together in 1 productProbioticsBstacked together in 1 productQuercetinBstacked together in 1 product
Product shelves
See all in Autophagy (1)

See Melatonin in context: the mechanism it acts through, the biomarker it moves, the products that dose it, and the trials that tested it.

View Melatonin on the Longevity Map →

Frequently asked questions

What is Melatonin?

A hormone your pineal gland makes at night to signal 'time to sleep'. Levels drop with age.

What dose of Melatonin should I take?

The trial dose in published human studies is 0.5 mg per day, with a range of 0.3 to 2 mg per day. Always consult a qualified clinician before starting any supplement.

Is Melatonin safe?

No formal UL; maximum dose has not been defined in trials, though EFSA and the American Academy of Sleep Medicine recommend maximum doses of 1 mg and 2 mg respectively. Considered relatively safe, but higher doses (>10 mg/day) increase minor adverse effects such as drowsiness, headache, and dizziness.

What is the best Melatonin supplement?

We track 1 products containing Melatonin. The top-ranked product scores 5.3 out of 10 on our composite scale, which evaluates dose, evidence, price, third-party testing, and transparency. See the comparison table above. Scores are editorial judgments, not a scientific standard.

What is the evidence grade for Melatonin?

Melatonin has evidence grade A, meaning it is well-supported by replicated human trials. Grade A means replicated human RCTs with hard endpoints. Grade B means human RCTs with biomarker outcomes. Grade C means mixed or small human trials. See our evidence grading methodology.

Independently checked

Data verification

Evidence grade
A
Replicated human RCTs with hard endpoints
Research dose
0.5 mg
Products tracked
1
Updated continuously
Safety signal
No formal UL; maximum dose has not been defined in trials...

Evidence grades are reviewed when new human RCTs are published. Product counts update automatically as new products are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.