supplementOTC supplementPrescription-only in the UK, EU and Australia
MelatoninBenefits, Dosage & Interactions
Melatonin is the hormone that signals biological night. Immediate-release tablets deliver a spike that fades within a few hours, which mainly helps with falling asleep. Research on Melatonin focuses on sleep quality. It is typically taken in the evening. The reported plasma half-life is about 0.75 hours, which shapes dosing frequency.
How much Melatonin do people take?
The pooled trials used amounts from 0.5 mg to 10 mg, with no clear dose-response for sleep onset. Route reported: Oral. Frequency reported: Once, before bedtime. These are amounts documented in the cited studies and labels for Melatonin — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
See the full reported protocol and its sourcesResearched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Evidence: Strong — 4 human randomized trials published.
Evidence strengthStrong · 4/4
PreclinicalStrong human evidence
4 human randomized trials published.
Quick answer
Melatonin is the hormone that signals biological night. Immediate-release tablets deliver a spike that fades within a few hours, which mainly helps with falling asleep. Extended-release forms spread delivery across the night to better mimic natural secretion, and are studied for staying asleep and for adults over 55, where natural output declines. Both shift circadian timing more than they sedate.
- What it is
- Hormone produced by the pineal gland in darkness
- Immediate release
- Peaks in under an hour; aimed at sleep onset
- Extended release
- Releases over several hours; aimed at sleep maintenance
- Half-life
- Roughly 30–60 minutes for immediate-release forms
- Studied amounts
- Commonly 0.5–5 mg; higher is not reliably better in trials
- Regulatory status
- Supplement in the U.S.; prescription-only in much of Europe
Compiled by DoseRoutine from public sources including NIH/MedlinePlus, the FDA label, Mayo Clinic and PubChem. Educational information, not medical advice.
Plasma half-life
~0.75 h
Typical timing
in the evening
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
- Reported amounts
- The pooled trials used amounts from 0.5 mg to 10 mg, with no clear dose-response for sleep onset[1]
- Route studied
- Oral[1]
- Frequency
- Once, before bedtime[1]
- Cycle length
- Trial durations ranged from days to weeks[1]
- Half-life
- Approximately 40–60 minutes for immediate-release melatonin[1]
- Storage
- Room temperature, away from light[1]
Reported for Melatonin in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Melatonin entry is written from. Each number matches an inline marker above.
- [1]Meta-analysis: melatonin for the treatment of primary sleep disordersFerracioli-Oda E, Qawasmi A, Bloch MH · PLoS One · 2013 · Peer-reviewed · PMID 23691095
References & Evidence
Sources on this page that document Melatonin dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Melatonin studied for?
What is Melatonin?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Melatonin is a hormone primarily produced by the pineal gland in the brain. It plays a crucial role in regulating the body's sleep-wake cycle, also known as the circadian rhythm. Melatonin production naturally increases in the evening, signaling to the body that it's time to prepare for sleep, and decreases in the morning. As a dietary supplement, melatonin is widely used to address various sleep-related issues, including insomnia, jet lag, and shift work disorder. It is available over-the-counter in various forms, such as pills, capsules, liquids, and chewables. While generally considered safe for short-term use, its efficacy and long-term safety continue to be subjects of scientific research. (NIH ODS)
What does the research say about Melatonin?
Tap a section to expand.
Melatonin exerts its effects primarily by binding to specific melatonin receptors (MT1 and MT2) located in the suprachiasmatic nucleus (SCN) of the brain, which is the body's central circadian clock. Activation of MT1 receptors contributes to the onset of sleep (sleep-promoting effects), while activation of MT2 receptors is involved in shifting the circadian rhythm (phase-shifting effects). By activating these receptors, exogenous melatonin can modulate the SCN's activity, thereby reinforcing the natural sleep-wake cycle and promoting drowsiness. Additionally, melatonin possesses antioxidant properties and can influence other physiological processes, although its primary role in supplementation is related to sleep regulation. (PubChem, DrugBank)
Source for this section: Sources for How does Melatonin work?: Jumps to this entry in the sources and references list at the end of the page.
Melatonin is primarily used for its potential to improve sleep and address circadian rhythm disturbances:
* **Insomnia:** Research suggests melatonin may be beneficial for certain types of insomnia, particularly primary insomnia in older adults. It may help reduce sleep latency (time it takes to fall asleep) and improve overall sleep quality. (Cochrane)
* **Jet Lag:** Taking melatonin can help resynchronize the body's internal clock with the new time zone, thereby reducing symptoms of jet lag, such as daytime fatigue, malaise, and reduced performance. (MedlinePlus)
* **Shift Work Disorder:** Individuals working rotating or night shifts often experience disrupted sleep patterns. Melatonin may help improve sleep efficiency and reduce daytime napping in some shift workers. (Cochrane)
* **Delayed Sleep-Wake Phase Disorder:** This condition involves a consistent delay in sleep and wake times compared to societal norms. Melatonin supplementation, taken at an appropriate time, can help shift the sleep-wake cycle earlier. (MedlinePlus)
* **Sleep Problems in Children with Neurodevelopmental Disorders:** Melatonin is sometimes used under medical supervision to help improve sleep in children and adolescents with conditions such as autism spectrum disorder and attention-deficit/hyperactivity disorder (ADHD), who often experience sleep difficulties. (Cochrane)
These benefits are generally observed with short-term use, and individual responses can vary. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Multiple systematic reviews and meta-analyses support melatonin's efficacy for certain sleep disorders. A Cochrane review on melatonin for sleep disorders in children and adolescents found that it significantly reduced sleep onset latency and increased total sleep time. Another Cochrane review on melatonin for jet lag concluded that it is effective in preventing or reducing jet lag, particularly when traveling across five or more time zones. For primary insomnia, particularly in older adults, some studies indicate modest benefits in improving sleep initiation and quality. The NIH ODS notes that while melatonin can be helpful for some sleep issues, more research is needed to fully understand its long-term effects and optimal dosing strategies for various conditions. Most studies rely on self-reported sleep quality and objective measures like actigraphy or polysomnography, though the latter is less common in supplemental research. (Cochrane, NIH ODS, MedlinePlus)
While generally considered safe for short-term use, melatonin can cause side effects in some individuals. Common side effects may include:
* Drowsiness or sleepiness (can persist into the next day)
* Dizziness
* Headache
* Nausea
Less common side effects can include:
* Irritability or mood changes
* Mild anxiety
* Stomach cramps
* Temporary feelings of depression
* Nightmares or vivid dreams
If you experience severe or persistent side effects, discontinue use and consult a healthcare professional. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Individuals should exercise caution when using melatonin, especially before operating machinery, driving, or performing tasks that require alertness, as it can cause drowsiness. Pregnant or breastfeeding individuals should consult a healthcare provider before using melatonin, as there is insufficient evidence regarding its safety in these populations. People with autoimmune diseases, seizure disorders, depression, or diabetes should also seek medical advice before use, as melatonin may interact with their conditions or medications. It is not recommended for children without medical supervision. Always use the lowest effective dose for the shortest duration necessary. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Melatonin is generally contraindicated in individuals with known hypersensitivity or allergy to melatonin or any ingredient in the formulation. Due to its potential to induce drowsiness, it should be used with extreme caution or avoided by individuals who must remain alert for critical tasks. Though not an absolute contraindication, certain conditions and medications warrant careful consideration and professional medical advice before using melatonin. These include severe liver or kidney impairment, or individuals taking immunosuppressants like cyclosporine. (EMA SmPC)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Melatonin can interact with several medications and substances, potentially altering their effects or increasing the risk of side effects. It is generally advised to avoid mixing melatonin with:
* **Anticoagulants/Antiplatelet drugs:** Melatonin may increase the risk of bleeding. Examples include warfarin, aspirin, clopidogrel, and NSAIDs.
* **Immunosuppressants:** Melatonin might stimulate immune function, potentially interfering with the effects of immunosuppressant medications like cyclosporine.
* **Seizure threshold lowering drugs:** Melatonin may lower the seizure threshold, potentially increasing the risk of seizures in susceptible individuals or those on seizure medications.
* **Diabetes medications:** Melatonin may affect blood sugar levels, requiring careful monitoring if used concurrently with antidiabetic drugs.
* **Contraceptive drugs:** Some hormonal contraceptives may increase endogenous melatonin production, potentially leading to additive effects.
* **Sedatives/CNS depressants:** Combining melatonin with alcohol, benzodiazepines (e.g., alprazolam, diazepam), or other sedatives can enhance drowsiness and central nervous system depression. (Mayo Clinic, MedlinePlus)
Always inform your healthcare provider about all supplements and medications you are taking to identify potential interactions. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Melatonin is typically taken shortly before bedtime. The precise timing can vary depending on the condition being addressed. For general sleep onset, it is commonly advised to take melatonin 30 minutes to 2 hours before the desired sleep time. For jet lag, timing is critical and often involves taking it close to the target bedtime in the new time zone. For delayed sleep-wake phase disorder, it might be taken several hours before bedtime to help shift the circadian rhythm earlier. For controlled or prescription-grade formulations, the timing and dosage must be set by a licensed clinician based on individual needs and the specific sleep disorder. Melatonin can be taken with or without food. (MedlinePlus)
Source for this section: Sources for When should you take Melatonin?: Jumps to this entry in the sources and references list at the end of the page.
Put it into practice
Reading about Melatonin is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Melatonin?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any glp1 + supplement | Note | Category ruleConfidence: theoretical | GLP-1 medications slow stomach emptying, changing how/when oral supplements absorb; rapid weight loss raises the importance of protein and micronutrients.Source pending | Time oral supplements when nausea is lowest; prioritize protein and micronutrients; discuss with your provider. |
| Any supplement + medication | Note | Category ruleConfidence: theoretical | Some supplements change how the body processes medications (absorption, liver enzymes, or additive effects).Source pending | Specific pairs are checked against a licensed drug database and shown with their own severity. Always confirm with your provider or pharmacist. |
| Zolpidem | Note | Compound pairConfidence: theoretical | Additive sedation possible.Source pending | Start at low melatonin dose (0.3–1 mg) when combined with prescription sedatives. |
| Eszopiclone | Note | Compound pairConfidence: theoretical | Additive sedation possible.Source pending | Start at low melatonin dose (0.3–1 mg) when combined with prescription sedatives. |
| Suvorexant | Note | Compound pairConfidence: theoretical | Additive sedation possible.Source pending | Start at low melatonin dose (0.3–1 mg) when combined with prescription sedatives. |
| Trazodone | Note | Compound pairConfidence: theoretical | Additive sedation possible.Source pending | Start at low melatonin dose (0.3–1 mg) when combined with prescription sedatives. |
| Mirtazapine | Note | Compound pairConfidence: theoretical | Additive sedation possible.Source pending | Start at low melatonin dose (0.3–1 mg) when combined with prescription sedatives. |
| Diphenhydramine | Note | Compound pairConfidence: theoretical | Additive sedation possible.Source pending | Start at low melatonin dose (0.3–1 mg) when combined with prescription sedatives. |
Frequently asked questions about Melatonin
Most research on melatonin's safety has focused on short-term use (up to a few months). While generally considered safe for short periods, less is known about the long-term effects of daily melatonin supplementation. It's advisable to discuss long-term use with a healthcare professional. (NIH ODS)
Melatonin is not considered to be habit-forming in the way many prescription sleep medications are. However, some individuals may feel reliant on it to fall asleep. It's best to use it intermittently or for specific needs rather than as a permanent solution without professional guidance. (Mayo Clinic)
The appropriate dose of melatonin can vary widely depending on the individual, the condition being treated, and the specific product. For supplemental use, common doses range from 0.3 mg to 5 mg, though some products contain higher amounts. Starting with the lowest effective dose is often recommended. For prescription-grade melatonin in certain countries, the dose is user-directed and must be set by a licensed clinician. It's always best to consult a healthcare provider for personalized dosing advice. (MedlinePlus)
No, melatonin does not work for everyone. Its effectiveness can vary based on individual physiology, the specific sleep problem, and the cause of sleep disturbance. It tends to be more effective for issues related to circadian rhythm disruption (like jet lag or delayed sleep phase) or in older adults with reduced natural melatonin production. (Cochrane)
As a supplement, Melatonin can overlap with other supplements, prescription medicines, hormones and peptides. Because Melatonin is usually taken in the evening, most avoidable conflicts come from what else lands in that same window. With a reported plasma half-life near 0.75 hours, separating doses can change the picture as much as removing one. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Melatonin with no sign-up.
Whether Melatonin fits alongside testosterone replacement therapy depends on the protocol — dose, ester and ancillaries such as HCG or anastrozole — and on current bloodwork. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
"Peptides" is not one category — healing peptides, GLP-1 agonists, growth-hormone secretagogues and melanocortins each behave differently next to Melatonin. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
A short plasma half-life of roughly 0.75 hours is why protocols often split Melatonin across the day rather than using a single dose. It is typically taken in the evening. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
Because Melatonin clears quickly (plasma half-life around 0.75 hours), a missed dose leaves a real gap in exposure rather than being buffered by what is still in your system. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Melatonin the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
Better for a different problem. Immediate release targets trouble falling asleep; extended release is designed for people who wake during the night, because blood levels are held up for longer. Trials of prolonged-release melatonin in adults over 55 show modest improvements in sleep quality and morning alertness. Neither form is a sedative in the way a sleeping pill is. This is educational information, not medical advice.
Generally no. Studies repeatedly find low amounts, often well under a milligram, produce circadian shifts comparable to much larger ones, while larger amounts increase next-day grogginess and headache. Many commercial products contain several times what has been tested, and independent analyses have found labeled content is frequently inaccurate. This is educational information, not medical advice.
Short and medium-term use has a reassuring safety record in adults, with headache, vivid dreams and next-morning drowsiness the usual complaints. Long-term nightly use has less data, particularly in children and adolescents, where hormone-timing effects are still being studied. Ongoing use for chronic insomnia is normally discussed with a clinician, since cognitive behavioral therapy for insomnia has stronger evidence. This is educational information, not medical advice.
The pooled trials used amounts from 0.5 mg to 10 mg, with no clear dose-response for sleep onset. Route reported: Oral. Frequency reported: Once, before bedtime. These are amounts documented in the cited studies and labels for Melatonin — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
Which studies looked at Melatonin?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Effect of melatonin supplementation on sleep quality: a systematic review and meta-analysis of randomized controlled trials(opens PubMed in a new tab)J Neurol · 2022 · PMID 33417003 · https://pubmed.ncbi.nlm.nih.gov/33417003/
- 2.Optimizing the Time and Dose of Melatonin as a Sleep-Promoting Drug: A Systematic Review of Randomized Controlled Trials and Dose-Response Meta-Analysis(opens PubMed in a new tab)J Pineal Res · 2024 · PMID 38888087 · https://pubmed.ncbi.nlm.nih.gov/38888087/
- 3.Efficacy of melatonin for chronic insomnia: Systematic reviews and meta-analyses(opens PubMed in a new tab)Sleep Med Rev · 2022 · PMID 36179487 · https://pubmed.ncbi.nlm.nih.gov/36179487/
- 4.Clinical pharmacokinetics of melatonin: a systematic review(opens PubMed in a new tab)Eur J Clin Pharmacol · 2015 · PMID 26008214 · https://pubmed.ncbi.nlm.nih.gov/26008214/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 896(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/896
Verify at
Publisher search links for Melatonin. These are places to check the information — they are not citations, so they are not numbered.
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- Mayo Clinic(publisher search, opens in a new tab)Mayo Clinic · publisher search
- European Medicines Agency(publisher search, opens in a new tab)European Medicines Agency · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed labeling archive(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Melatonin?
Plain-text summary, safe to quote verbatim:
Melatonin is the hormone that signals biological night. Immediate-release tablets deliver a spike that fades within a few hours, which mainly helps with falling asleep. Research on Melatonin focuses on sleep quality. It is typically taken in the evening. The reported plasma half-life is about 0.75 hours, which shapes dosing frequency.
Source: DoseRoutine — https://doseroutine.com/library/melatonin
Melatonin cheat sheet
DoseRoutine cheat sheet · Supplement
Melatonin
Melatonin is the hormone that signals biological night. Immediate-release tablets deliver a spike that fades within a few hours, which mainly helps with falling asleep.
Evidence
Strong
4 human randomized trials published.
Studied range
The pooled trials used amounts from 0.5 mg to 10 mg, with no clear dose-response for sleep onset
Route
Oral
Frequency studied
Once, before bedtime
Half-life
~0.75 h
Timing
in the evening
Storage
Room temperature, away from light
OTC supplementPrescription-only in the UK, EU and AustraliaSleep
Key references
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/melatonin
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Melatonin — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/melatonin
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