Melatonin

Natural hormone that regulates sleep-wake cycles, supports circadian rhythm, and provides antioxidant protection

Scientific nameN-acetyl-5-methoxytryptamine FormulaC13H16N2O2 Molecular weight232.28 g/mol CAS73-31-4

50 absorption score

8 safety / 10

10 USD per month

6 documented interactions

Check it against something

Evidence level B

Melatonin with:

78 out of 100

Works better together Compatible. Timing differs, so follow each supplement's own window.

Check it against your whole stack →

What it does

mechanism and evidence for each claim

Improved sleep onset and quality

Reduces time to fall asleep and improves overall sleep quality

Binds to melatonin receptors in brain to promote sleepiness Evidence A-grade 30 minutes to 2 hours

Jet lag and shift work support

Helps reset circadian rhythm and reduce jet lag symptoms

Resynchronizes internal body clock with external light-dark cycles Evidence A-grade 1-3 days for jet lag

Circadian rhythm regulation

Supports healthy sleep-wake cycles and circadian timing

Acts as primary circadian rhythm signal from pineal gland Evidence A-grade 1-2 weeks for rhythm adjustment

Antioxidant and neuroprotective effects

Provides powerful antioxidant protection and brain health support

Directly scavenges free radicals and enhances antioxidant enzymes Evidence B-grade Ongoing with regular use

Immune system support

May enhance immune function and reduce inflammation

Modulates immune cell activity and cytokine production Evidence C-grade 2-8 weeks

Others take these for the same thing

Same goal, different mechanism — check any of them against this one

Ashwagandha Stress management & energy 300-600mg A 75% Magnesium Glycinate Superior absorption sleep & muscle support 200-600 mg A 90% L-Theanine Calm focus & stress relief 100-400mg B 90% Boron - Essential Trace Mineral for Bone and Hormone Health Bone health & hormone support 3-10mg daily B 85% Glycine Sleep quality & collagen support 3-10g A 95% GABA (Gamma-Aminobutyric Acid) Natural relaxation & anxiety relief 250-1000mg C 30%

Every pair we checked

12 combinations scored by the engine

Melatonin + Caffeine Caffeine opposes melatonin's sleep-promoting effects Needs attention 40

Melatonin + Creatine Monohydrate No documented interaction either way No known interaction 70

Melatonin + Vitamin D3 No documented interaction either way No known interaction 70

Melatonin + Calcium Carbonate No documented interaction either way No known interaction 70

Melatonin + Whey Protein No documented interaction either way No known interaction 70

Melatonin + Lactase No documented interaction either way No known interaction 70

Melatonin + Bovine Collagen No documented interaction either way No known interaction 70

Melatonin + DHA No documented interaction either way No known interaction 70

Melatonin + Turmeric No documented interaction either way No known interaction 70

Melatonin + Magnesium Oxide Enhanced relaxation and sleep quality Works better together 78

Melatonin + L-Theanine Enhanced relaxation without sedation Works better together 78

Melatonin + Valerian Root Enhanced sleep promotion Works better together 83

Dosage

30 60 minutes before bed

Daily0.5-3mg

Sleep onset0.5-3mg before bedtime

Jet lag0.5-3mg at destination bedtime

Circadian adjustment0.3-1mg timed appropriately

Antioxidant1-3mg (higher doses for this purpose)

When to expect it

First Effects30 minutes to 2 hours for sleep onset

Peak Benefits1-2 weeks for sustained sleep improvement

Deficiency DevelopmentImmediate return of sleep issues when stopped

Toxicity OnsetVery rare, mainly daytime sedation

How to measure it

$100-200

MarkerSalivary melatonin levels or urinary 6-sulfatoxymelatonin

OptimalPeak at night: 10-80 pg/mL, Low during day: <10 pg/mL

Deficient belowBlunted nighttime rise or low peak levels

FrequencyOnly for circadian rhythm assessment - not routine

What people actually reported to the FDA

CAERS, 370 reports naming it as the suspect

Most reported effects

Dizziness 36

Nausea 34

Insomnia 30

Diarrhoea 29

Dyspnoea 29

Named as the suspect 370 reports of 661 that mention it at all

Serious outcome 86% hospitalisation, emergency room or worse

Other Serious or Important Medical Event242

Hospitalization86

Visited Emergency Room70

Reports are voluntary and unverified — they record what someone experienced while taking something, not what the compound caused. Counts skew towards products people take a lot of, and a serious outcome is more likely to be reported than a mild one, so these are not rates. How we filter them →

What actually reaches you

The label counts the carrier, your body does not

Absorption Moderate 50 of 100 · middle of the range for this compound

Delivered daily 0.9 mg

Cost per 10 mg delivered $3.81 comparative — uses the absorption score, not a measured percentage

Works better with

3 documented

Magnesium

Enhanced relaxation and sleep quality

Complementary effects on nervous system relaxation · level B

L Theanine

Enhanced relaxation without sedation

Complementary calming effects through different pathways · level B

Valerian Root

Enhanced sleep promotion

Complementary sleep-promoting mechanisms · level C

What not to take with Melatonin

3 documented

Caffeine

Caffeine opposes melatonin's sleep-promoting effects

Adenosine receptor antagonism opposes sleep drive · major significance

Blue Light Exposure

Blue light suppresses natural melatonin production

Light exposure inhibits pineal melatonin synthesis · major significance

Alcohol

Alcohol disrupts sleep quality despite initial sedation

Interferes with sleep architecture and REM sleep · moderate significance

Medication interactions

Discuss these with a pharmacist before combining

blood-thinners-warfarin Moderate

May increase bleeding risk

What to do: Monitor INR closely

immunosuppressants Moderate

May enhance immune function countering drug effects

What to do: Monitor immune function

diabetes-medications Minor

May affect blood glucose control

What to do: Monitor blood glucose

Available forms

bioavailability compared

Immediate Release Melatonin 50

Immediate Release Melatonin: Highly effective, Natural hormone, Inexpensive, Fast acting

Food sources

before you supplement

Tart cherries Small amounts of natural melatonin · 40

Walnuts and almonds Trace amounts · 30

Tomatoes and grapes Very small amounts · 25

Supplements 0.3-10mg per dose · 50

Too little

deficiency signs

Difficulty falling asleep (sleep onset insomnia)
Poor sleep quality and frequent awakenings
Jet lag and circadian rhythm disorders
Delayed sleep phase syndrome
Increased oxidative stress
Immune system dysfunction
Seasonal affective disorder symptoms

Too much

toxicity signs

Generally safe but potential side effects:
Daytime drowsiness and grogginess
Vivid dreams or nightmares
Headaches in some individuals
Potential hormonal effects with high doses

Who benefits most

insomnia-sleep-disorders

Highly effective for sleep onset insomnia and sleep quality

0.5-3mg 30-60 minutes before desired sleep time

jet-lag-travelers

Excellent for resetting circadian rhythm and reducing jet lag

0.5-3mg at destination bedtime

shift-workers

Helps adapt to changing sleep schedules

0.5-3mg before desired sleep period

aging-adults

Compensates for natural decline in melatonin production

0.5-2mg before bedtime

delayed-sleep-phase

Helps advance sleep timing for night owls

0.5-3mg 5-6 hours before current sleep time

Where to buy it

compare forms first

Look for Melatonin at 0.5-3mg per serving. The form that matters here is Immediate Release Melatonin.

Find on Amazon

Affiliate link — we may earn a commission at no cost to you.

What else affects it

Beyond other supplements

Alcohol

Alcohol disrupts sleep quality despite initial sedation

Interferes with sleep architecture and REM sleep

How it works

Binds to MT1 and MT2 melatonin receptors in suprachiasmatic nucleus
Promotes sleepiness and reduces core body temperature
Synchronizes circadian rhythms with light-dark cycles
Acts as powerful antioxidant protecting cells from oxidative damage
Modulates immune system function and inflammation
Influences reproductive hormone cycles

Key findings

what the evidence supports

Highly effective for sleep onset insomnia and circadian rhythm disorders
Excellent for jet lag and shift work sleep disorders
Lower doses (0.3-1mg) often as effective as higher doses
Generally safe but timing and dose are critical for effectiveness

Sources: NIH Examine.com · data reviewed 2026-08-02

Compiled by Denis, who maintains this database and holds no medical qualification — every figure here is sourced or derived, never asserted. How we calculate it →

Common questions

What are the benefits of Melatonin?

Documented effects: Improved sleep onset and quality; Jet lag and shift work support; Circadian rhythm regulation; Antioxidant and neuroprotective effects. Reduces time to fall asleep and improves overall sleep quality

How much Melatonin should you take per day?

The common daily range is 0.5-3mg. By goal — sleep onset: 0.5-3mg before bedtime; jet lag: 0.5-3mg at destination bedtime; circadian adjustment: 0.3-1mg timed appropriately; antioxidant: 1-3mg (higher doses for this purpose).

When is the best time to take Melatonin?

30 60 minutes before bed. First effects are typically reported within 30 minutes to 2 hours for sleep onset.

What are the side effects of Melatonin?

At excessive doses: Generally safe but potential side effects:, Daytime drowsiness and grogginess, Vivid dreams or nightmares, Headaches in some individuals, Potential hormonal effects with high doses. Safety rating at normal doses is 8 out of 10.

What should you not take with Melatonin?

Separate it from Caffeine, Blue Light Exposure, Alcohol by two to four hours. Caffeine opposes melatonin's sleep-promoting effects

Does Melatonin interact with medications?

Documented interactions with blood-thinners-warfarin, immunosuppressants, diabetes-medications. Discuss these with a pharmacist before combining.

How do you know if you need Melatonin?

The marker is Salivary melatonin levels or urinary 6-sulfatoxymelatonin, optimal range Peak at night: 10-80 pg/mL, Low during day: <10 pg/mL. Common deficiency signs: Difficulty falling asleep (sleep onset insomnia), Poor sleep quality and frequent awakenings, Jet lag and circadian rhythm disorders, Delayed sleep phase syndrome.

Taken for

28 Sleep & Stress

Melatonin · Magnesium Glycinate · Ashwagandha

27 Hormones

Melatonin · Vitamin B6 (Pyridoxine HCl) · Vitamin B6 (P5P)