Is it dangerous to take melatonin every day?

What is melatonin?

What role does melatonin play in sleep?

Melatonin is a hormone secreted directly into the bloodstream by the pineal gland (a small cone-shaped area in the centre of the brain, also known as the epiphysis cerebri).

It helps to stabilise circadian rhythms and regulate certain physiological processes such as sleep and food intake.

Once in the bloodstream, it activates a number of vascular receptors and supports a state of ‘quiet wakefulness’ conducive to falling asleep, by lowering body temperature and reducing the secretion of cortisol (the stress hormone).

Melatonin production increases sharply at the end of the day, as natural light starts to fade. This is the signal that the ‘normal’ time to go to bed is approaching.

Its concentration in the blood continues to increase, reaching a peak at around 3am or 4am, before returning to minimum levels after sunrise, at around 8am.

Why take melatonin?

Although melatonin is produced naturally by the body, many people who experience disturbed sleep (insomnia, jetlag, night shift work, circadian rhythm disorders…) choose to take a melatonin supplement to boost their levels of this hormone at the right moment, in order to fall asleep faster and readjust their biological clock (1-2).

Melatonin supplementation may be helpful for those who regularly spend time looking at screens in the evening, as the light intensity of digital devices affects melatonin secretion and delays the circadian clock.

Are there any risks associated with taking melatonin?

Can you expect to suffer side-effects from taking melatonin?

In healthy individuals, taking melatonin in the afternoon or early evening can produce feelings of fatigue, lack of energy, drowsiness, and the desire to sleep, effects which are mostly consistent and desired.

If too much melatonin is taken, these effects can persist the following day (with a residual presence in the blood), but they usually disappear when supplementation ceases.

If melatonin is taken earlier in the day, there’s a risk of disrupting the sleep-wake cycle (which may also be the desired effect in the case of jet-lag).

Unlike benzodiazepines, melatonin supplementation will not, in principle, lead to any changes in sleep architecture at the maximum dose recommended (2mg a day for an adult), at least when taken for short periods.

What are the potential effects over the long-term?

Although most of melatonin’s known adverse effects and potential interactions are not serious, and preliminary studies on its long-term impact are reassuring, it is not advisable to take it for long periods, as research data is still limited (3).

This is particularly so for at-risk population groups, such as women who are pregnant or breastfeeding, children, and adolescents (a potential effect on puberty has yet to be ruled out), those suffering from auto-immune inflammatory diseases, epilepsy, asthma, mood, behaviour or personality disorders, as well as those on long-term medication (including antidepressants).

Several possible risks from persistent, daily use still need to be completely ruled out: an unlikely bone fragility effect, a potential effect on growth (4) and a possible link to depression (5).

However, except in the case of repeated, very high-dose use (hundreds of mg a day), melatonin is not associated with any impact on the liver or heart, and neither does it promote weight gain (6).

Short-term use of melatonin: our tips for safe and effective supplementation

For the time being, the advice is to take melatonin supplements on a short-term basis, for a few days to a few weeks (usually 1-2 months maximum), the time it takes to ‘recalibrate’.

In addition to this model, occasional, isolated use is also possible.

Be sure to seek advice from a health professional if necessary.

Is melatonin a drug?

Melatonin is different from other hormones. In contrast to the majority of molecules with endocrine functions, it is not subject to negative feedback (no risk of addiction).

In other words, long-term supplementation with melatonin does not lead to atrophy of the pineal gland nor a reduction in endogenous production (7-9).

Once melatonin supplementation ceases, there is no rebound insomnia effect, nor withdrawal syndrome (10). Melatonin is therefore not a drug.

How should melatonin supplements be taken?

Dose and time of day

The melatonin dose recommended is between 1mg and 2mg a day (as offered by Melatonin 1mg, 2 tablets of which provide 2mg of melatonin a day).

In terms of the right time to take it, some recommend 2 hours before bed to facilitate a gradual build-up of the ‘sleep hormone’, while others advise 15 minutes to an hour before bed, believing that we absorb melatonin more rapidly … If in doubt, follow the instructions on the label.

Other forms of melatonin

Melatonin can also be taken in the form of a spray (such as the product Melatonin Spray) to promote its entry into the bloodstream via the oral mucosa and thus maximise its absorption.

You can also take specific sleep formulations in which melatonin is combined with other natural compounds (such as Advanced Sleep Formula rich in relaxing plant extracts).