Melatonin
Also known as exogenous melatonin, n-acetyl-5-methoxytryptamine
Key takeaways
- Melatonin is effective for ameliorating preoperative and postoperative anxiety in adults (PMID: 33319916).
- Melatonin positively impacts quality of life and symptoms in cancer patients (PMID: 36104141).
- Evidence for melatonin's role in reducing postoperative delirium is not strongly supported (PMID: 36990485).
What the research shows
AI-synthesized from 291 peer-reviewed sources · Updated 2025
Melatonin is a hormone supplement primarily used to regulate sleep-wake cycles and manage related anxiety. Research indicates efficacy in reducing preoperative anxiety and improving quality of life in cancer patients, though results for delirium prevention and insomnia are mixed.
By condition
Preoperative and Postoperative Anxiety
Strong
Meta-analyses indicate melatonin is an effective, low-toxicity alternative to benzodiazepines for reducing anxiety surrounding surgery.
Cancer-related Quality of Life
Moderate
Evidence suggests melatonin can improve quality of life and alleviate certain symptoms in patients with cancer.
Postoperative Delirium
Weak
Recent meta-analyses suggest insufficient or inconsistent evidence to conclude that melatonin significantly reduces the incidence of postoperative delirium.
Insomnia Disorder
Moderate
Network meta-analyses place melatonin as one of several pharmacological options for insomnia, though its comparative efficacy varies.
Dementia-related Sleep Disturbances
Weak
Evidence for the use of pharmacotherapies, including melatonin, for sleep disturbances in dementia remains limited.
Effective doses
Specific dose ranges were not provided in the provided abstracts.
Safety & interactions
Generally considered a low-toxicity alternative to benzodiazepines; however, specific contraindications and drug interactions should be reviewed by a healthcare provider.
Limitations
Many studies focus on specific clinical populations (e.g., surgical or oncology patients), and there is a need for more consistent data regarding long-term insomnia management and delirium prevention.
Top-rated Melatonin products
Ranked by safety score and evidence coverage
Drug–supplement interactions
6 documented interactions
| Drug | Severity | Mechanism | Evidence |
|---|---|---|---|
| Alpelisib | Moderate | Interaction identified from DDInter 2.0 database. Specific drugs: Alpelisib | ddinter-verified |
| Antiplatelet Drugs | Moderate | Interaction identified from DDInter 2.0 database. Specific drugs: Anagrelide | ddinter-verified |
| Fluvoxamine | Moderate | Fluvoxamine inhibits CYP1A2 and CYP2C19, which metabolize melatonin. Combined us | well-established |
| Iron Chelators | Moderate | Interaction identified from DDInter 2.0 database. Specific drugs: Deferasirox | ddinter-verified |
| Sedatives | Moderate | Melatonin has sedative properties that may add to CNS depressant effects. | probable |
| Warfarin | Minor | Melatonin may affect CYP2C9 activity, potentially altering warfarin metabolism. | possible |
How it's sold
Data aggregated from 1,005 product labels
Research evidence
Showing top 10 of 291 sources, sorted by quality
**Siddiqi et al., 2016** | Cochrane Database Syst Rev | Meta Analysis Siddiqi Najma, Harrison Jennifer K, ... Simpkins Samantha A. Interventions for preventing delirium in hospitalised non-ICU patients. Cochrane Database Syst Rev. 2016-Mar-…
BACKGROUND: Anxiety in relation to surgery is a well-known problem. Melatonin offers an alternative treatment to benzodiazepines for ameliorating this condition in the preoperative and postoperative periods. OBJECTIVES: To assess the effect…
**Fan et al., 2022** | BMJ Open | Meta Analysis Fan Rongrong, Bu Xiaofan, ... Li Xuying. Effect of melatonin on quality of life and symptoms in patients with cancer: a systematic review and meta-analysis of randomised controlled trials. BMJ…
**Agarwal et al., 2022** | Cochrane Database Syst Rev | Meta Analysis Agarwal Sri Mahavir, Stogios Nicolette, ... Hahn Margaret. Pharmacological interventions for prevention of weight gain in people with schizophrenia. Cochrane Database Sys…
BACKGROUND: Anxiety in relation to surgery is a well-known problem. Melatonin offers an atoxic alternative to benzodiazepines in ameliorating this condition in the pre- and postoperative period. OBJECTIVES: To assess the effect of melatonin…
**Kampling et al., 2021** | Cochrane Database Syst Rev | Meta Analysis Kampling Hanna, Baumeister Harald, ... Mittag Oskar. Prevention of depression in adults with long-term physical conditions. Cochrane Database Syst Rev. 2021-Mar-05;3(3):…
**De et al., 2022** | Lancet | Systematic Review De Crescenzo Franco, D'Alò Gian Loreto, ... Cipriani Andrea. Comparative effects of pharmacological interventions for the acute and long-term management of insomnia disorder in adults: a syst…
**Barnes et al., 2023** | BMJ Open | Meta Analysis Barnes Jonathan, Sewart Emma, ... Mouton Ronelle. Does melatonin administration reduce the incidence of postoperative delirium in adults? Systematic review and meta-analysis. BMJ Open. 2023…
**Gartlehner et al., 2015** | Cochrane Database Syst Rev | Meta Analysis Gartlehner Gerald, Nussbaumer Barbara, ... Winkler Dietmar. Second-generation antidepressants for preventing seasonal affective disorder in adults. Cochrane Database S…
**Mishu et al., 2021** | Cochrane Database Syst Rev | Meta Analysis Mishu Masuma Pervin, Uphoff Eleonora, ... Siddiqi Najma. Interventions for preventing type 2 diabetes in adults with mental disorders in low- and middle-income countries. C…
Frequently asked questions
What is melatonin and what is it primarily used for?
Melatonin is a hormone supplement primarily used to regulate sleep-wake cycles and manage related anxiety. Research indicates it is effective for reducing preoperative anxiety and improving quality of life in cancer patients, though its efficacy for insomnia and delirium prevention is mixed.
Does melatonin work for preoperative anxiety?
Yes, there is strong evidence that melatonin is an effective, low-toxicity alternative to benzodiazepines for reducing anxiety surrounding surgery. Meta-analyses confirm its efficacy in ameliorating preoperative and postoperative anxiety in adults.
Is melatonin effective for treating insomnia?
There is moderate evidence that melatonin is one of several pharmacological options for insomnia disorder, though its comparative efficacy varies. Network meta-analyses place it among treatment options, but results are not as definitive as for anxiety.
Can melatonin prevent postoperative delirium?
No, the evidence for this is weak. Recent meta-analyses suggest there is insufficient or inconsistent evidence to conclude that melatonin significantly reduces the incidence of postoperative delirium.
What are the safety concerns and drug interactions with melatonin?
Melatonin has moderate interactions with fluvoxamine, which can dramatically increase melatonin levels, and with sedatives, which may cause excessive sedation. It also has a minor possible interaction with warfarin that could alter INR levels. You should review specific contraindications with a healthcare provider.
Who should avoid taking melatonin or use caution?
Individuals taking medications such as fluvoxamine, sedatives, or warfarin should consult a healthcare provider due to potential interactions. Because specific contraindications exist and safety profiles vary, it is important to review personal medical history with a professional before use.
Does melatonin help with dementia-related sleep disturbances?
The evidence for melatonin's use in dementia-related sleep disturbances is weak. Research indicates that evidence for pharmacotherapies, including melatonin, for these specific sleep issues remains limited.