What is it used for?
(Used as a) sleep aid (to help promote sleep) [Source note 2].
Helps increase the total sleep time (aspect of sleep quality) in people suffering from sleep restriction or altered sleep schedule (e.g. shift-work and jet lag) [Source note 3].
Helps (to) prevent and/or reduce the effects of jet lag/minimize jet lag (e.g. daytime fatigue, sleep disturbance) (for people/if travelling by plane easterly across two or more time zones/flying east over two or more time zones) [Source note 4].
Helps (to) speed up/reduce the time it takes to fall asleep (sleep onset latency aspect of sleep quality) in people who fall asleep slowly/with delayed sleep phase disorder [Source note 5].
Helps (to) re-set the body's sleep-wake cycle (aspect of the circadian rhythm) [Source note 6].
Note: The above claims can be combined on the product label (e.g., Helps re-set the body's sleep-wake cycle (aspect of the circadian rhythm) and increase the total sleep time (aspect of sleep quality) in people suffering from sleep restriction or altered sleep schedule).
What this guide covers
Restrictions when this reference is combined with other references (source review category II and III):
Products containing melatonin must not indicate any uses or purposes related to the maintenance/support of good/general health.
Products providing a quantity of melatonin that meets the minimum therapeutic dose must indicate a use or purpose associated with melatonin.
this reference supports the use of melatonin when needed only, for occasional sleeplessness. As such, it is not compatible in combination with ingredients which are required to be taken daily in order to exert a beneficial health effect.
Who does this guide cover?
Adults 18 years and older
How is it taken?
Oral
Which forms are covered?
this reference excludes foods or food-like dosage forms as indicated in the Compendium of references Guidance Document.
Note that this list does not include prolonged-release, extended-release or delayed-release dosage forms.
Quantities
All uses except jet lag
0.1-10 milligrams of melatonin, per day [Source note 7].
Jet lag
0.5-10 milligrams of melatonin, per day [Source note 8].
How is it used?
Take as needed, 30 to 60 minutes before bedtime [Source note 9].
How long is it used?
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
Warnings and precautions
All uses
Ask a healthcare professional before use if you are taking medications for seizure, blood pressure, to suppress the immune system, to affect mental state or increase sedation, steroids or blood thinners [Source note 10].
Ask a healthcare professional before use if you have cardiovascular, immune, liver or kidney disease, seizure disorder, asthma or diabetes [Source note 11].
When using this product avoid taking with alcohol or products that cause drowsiness [Source note 12].
When using this product avoid driving or using machinery for 5 hours [Source note 13].
Ask a healthcare professional if sleeplessness persists for more than 4 weeks (chronic insomnia) [Source note 14].
When should it be avoided?
Do not use if you are pregnant or breastfeeding [Source note 15].
Possible side effects
Stop use if allergy occurs or if you experience headache, confusion, or nausea [Source note 16].
Storage
Must be established in accordance with the requirements described in the applicable product regulations.
Preparation details
Ingredient identity, preparation requirements, and other details that define the scope of this guide.
Ingredients and preparations
| Proper name(s) | Common name(s) | Source information / Source ingredient(s) | Source information / Preparation(s) |
|---|---|---|---|
|
| Melatonin | Synthetic |
References: Proper names: RSC 2023; Buscemi et al. 2004; Common names: RSC 2023; Buscemi et al. 2004; Source information: RSC 2023.
Other ingredients
Must be chosen from the current source ingredient database and must meet the limitations outlined in the database.
Preparation and quality requirements
The finished product specifications must be established in accordance with the requirements described in the source authority source’s product quality guidance.
The active ingredient must comply with the requirements outlined in the source ingredient database.
Guide change history
Updates to this SupplementSafety.org guide.
Minor updates
Updated guide wording, organization, and source presentation. Added our editorial change history.
Initial release
Initial SupplementSafety.org guide prepared from source reference material.
Validation: Not yet completed. Editorial updates do not constitute clinical validation.
Sources
Source information
This guide organizes source material about uses, preparations, amounts, and precautions. Read the conditions alongside each statement; the information may apply only to particular preparations or populations.
The source document includes supporting references. We have not independently summarized or assessed every cited study for this guide.
- Source document version
- December 19, 2025
- Source captured
- Aug 15, 2026
- Editorial work
- Editorial preparation. Independent clinical review has not been recorded for this guide.
Full citations are available through the link above. Verification is required to open them; reading this guide does not require verification.
Taking a medication too?
Explore our supplement–medication interaction checker. Its coverage and review status are shown with the results; a missing finding does not establish that a combination is safe.