Melatonin: A Science-Based Guide
What is melatonin?
Melatonin is a hormone produced by the pineal gland in the brain. It plays a key role in the circadian rhythm — the body's internal clock that regulates the sleep-wake cycle.
Melatonin production is directly linked to the light-dark cycle. When darkness falls, melatonin production increases, signalling to the body that it is time to rest. In the presence of light, melatonin production decreases. This natural process helps the body adapt to the day-night rhythm.
In Estonia's climate, where daylight is scarce during winter and summer nights barely get dark, natural melatonin production may be disrupted. Long dark winters and bright summer nights create unusual lighting conditions that can affect the body's internal clock.
As a supplement, melatonin is available in tablets, capsules, and drops. In the European Union, only EFSA (European Food Safety Authority) approved health claims may be used in the marketing of melatonin supplements.
How does it work?
Melatonin production begins in the brain, in the pineal gland. The process works as follows: the suprachiasmatic nucleus (SCN) in the brain receives information about light levels from the retina. When darkness falls, the SCN sends a signal to the pineal gland, which begins producing melatonin from the amino acid tryptophan via its intermediate product serotonin.
The produced melatonin is released into the bloodstream and reaches various tissues. Melatonin binds to specific receptors — MT1 and MT2. MT1 receptors are involved in inducing drowsiness, while MT2 receptors participate in synchronising the body's circadian rhythm.
Melatonin levels in the blood are highest at night, typically around 2-4 AM, and drop in the morning with exposure to light. This natural rhythm can be disrupted by crossing time zones (jet lag), shift work, or unusual lighting conditions.
Melatonin taken as a supplement mimics the action of the body's natural melatonin by binding to the same MT1 and MT2 receptors.
Supported benefits (EFSA-approved claims only)
The following benefits are based on health claims authorised under Commission Regulation (EU) No 432/2012. Melatonin has only two approved health claims:
Jet lag
- Melatonin contributes to the alleviation of subjective feelings of jet lag — this is an EFSA-approved claim under Regulation (EU) No 432/2012. The claim is valid when at least 0.5 mg of melatonin is consumed close to bedtime on the first day of travel and on the following days after arrival at the destination.
Time to fall asleep
- Melatonin contributes to the reduction of time taken to fall asleep — this is an EFSA-approved claim under Regulation (EU) No 432/2012. The claim is valid when 1 mg of melatonin is consumed close to bedtime.
Important note: Claims such as "improves sleep quality", "helps you sleep better", "treats insomnia", "regulates sleep cycle", or "natural sleep aid" are not permitted. These are either unsubstantiated, overly broad, or medical claims that may not be used for food supplements.
How to take it
Melatonin is taken close to bedtime, as specified in the conditions of the EFSA-approved health claims.
Guidelines:
- Always follow the recommended daily serving stated on the label — do not exceed it
- For alleviating jet lag: at least 0.5 mg close to bedtime on the first day of travel and on the following days after arrival at the destination
- For reducing the time taken to fall asleep: 1 mg close to bedtime
- Take melatonin 30-60 minutes before your planned bedtime
- Avoid bright light (especially blue light from screens) after taking melatonin
- There is no benefit to taking melatonin during the day or in the morning, as this may interfere with the natural circadian rhythm
Northern climate note: Estonia's long dark winters and bright summer nights create unusual lighting conditions. In winter, darkness may arrive as early as the mid-afternoon; in summer, it may not get properly dark at all. These conditions can affect the body's natural melatonin production and circadian rhythm.
Who should use it?
A melatonin supplement may be relevant for:
- Travellers crossing time zones — people who fly long distances and experience jet lag. Melatonin contributes to the alleviation of subjective feelings of jet lag (EFSA-approved claim, at least 0.5 mg close to bedtime).
- People who wish to reduce the time taken to fall asleep — those who may take longer than usual to fall asleep. Melatonin contributes to the reduction of time taken to fall asleep (EFSA-approved claim, 1 mg close to bedtime).
- Residents of Estonia and Nordic countries — long dark winters and bright summer nights create unusual lighting conditions that can affect the body's natural circadian rhythm. In winter, darkness comes early; in summer, darkness may not arrive at all — these are conditions where the body's day-night rhythm may need support.
Who should NOT use it?
Melatonin supplementation is not recommended for the following groups:
- Pregnant and breastfeeding women — safety data are insufficient. Consult your doctor
- Children and adolescents — melatonin is intended for adults. Use in children should be discussed with a doctor
- People with autoimmune diseases — melatonin may influence immune system processes. Consult your doctor
- People taking blood-thinning medications (e.g., warfarin) — potential interactions. Consult your doctor
- People taking epilepsy medications — potential interactions. Consult your doctor
- People taking sedatives or sleeping pills — melatonin should not be combined without medical approval
- People operating heavy machinery or driving — melatonin may cause drowsiness. Do not take immediately before activities requiring alertness
When in doubt, always consult your doctor or pharmacist.
Frequently Asked Questions
Is melatonin habit-forming?
Melatonin is not known to be an addictive substance. It is not classified as a narcotic or psychotropic substance. However, it is advisable to use melatonin thoughtfully and according to the instructions on the label, rather than as a long-term daily habit without a specific need.
What is the correct dose?
The EFSA-approved claims apply at the following doses: at least 0.5 mg for alleviating jet lag and 1 mg for reducing the time taken to fall asleep, both taken close to bedtime. Always follow the recommended dosage on the label and do not exceed it.
When should I take melatonin?
Melatonin is taken close to bedtime. The optimal time is 30-60 minutes before your planned sleep time. For jet lag, start taking it on the first day of travel and continue on the following days after arrival at the destination.
Can I take melatonin every night?
Melatonin is a food supplement, not a medicine. The EFSA-approved claims do not define a maximum duration of use. However, it is advisable to use melatonin thoughtfully. If difficulty falling asleep persists, consult your doctor to identify possible underlying causes.
Can I combine melatonin with other supplements?
Melatonin can generally be combined with common supplements such as vitamins and minerals. However, caution is needed when combining with medications — especially blood-thinning medications, epilepsy medications, sedatives, and sleeping pills. Always consult your doctor if you are taking any medications.
Does melatonin have side effects?
Melatonin is generally well tolerated. Some people may experience drowsiness (which is an expected effect), headache, or gastrointestinal discomfort. If side effects occur, discuss them with your doctor. Do not drive or operate machinery immediately after taking melatonin.
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