Does melatonin cause weight gain?


Does melatonin cause weight gain?

Melatonin is primarily known for its benefits in regulating sleep. It is often used to treat sleep disorders, such as insomnia, or to adapt to time changes, such as jet lag. However, a common question remains: can melatonin influence weight gain? Some research suggests an indirect link between melatonin and body weight, but results vary depending on individuals and conditions of use.

 

1. Indirect effect of melatonin on weight regulation

Although melatonin is primarily used for its effects on sleep, its influence on body weight appears to be indirect. By promoting restful and quality sleep, melatonin plays a role in regulating several hormones that control appetite. Two key hormones are particularly concerned: leptin and ghrelin.

  • Leptin is a hormone produced by fat cells and its role is to signal to the brain that the body has sufficient energy reserves. When we sleep well, leptin production is optimized, which helps us regulate our appetite naturally, limiting excessive food cravings.

  • Ghrelin, meanwhile, is nicknamed the "hunger hormone." It stimulates appetite and is produced primarily during periods of wakefulness and sleep deprivation. Poor sleep, especially poor sleep quality, leads to an increase in ghrelin production, which can lead to an increased feeling of hunger, especially at night.

By regulating these hormones, melatonin allows for a better balance between appetite and satiety. Thus, a person who benefits from quality sleep, facilitated by melatonin, may notice a reduction in nocturnal cravings, which could indirectly help prevent weight gain associated with overeating in the evening. This hormonal regulation action can be particularly useful for people who snack frequently due to lack of sleep or stress.

 

2. Specific cases: effects of high and prolonged doses

While melatonin can indeed have an indirect beneficial effect on weight management through its influence on sleep, it is important to note that very high and prolonged doses of melatonin could have opposite effects in some cases. Some studies have suggested that excessive melatonin intake could negatively disrupt hormonal balance, affecting metabolism regulation and, in some cases, contributing to weight gain. However, these results are rare and only concern a small number of people who took large doses over a long period.

The hypothesis that melatonin could affect weight gain in case of overdose is based on the idea that abnormally high levels of this hormone could disrupt the activity of certain endocrine glands, such as the thyroid gland, which plays a key role in metabolism. One hypothesis is that this could lead to a slowdown in metabolism, which in turn could promote weight gain. However, these effects are still largely theoretical and require additional research to be confirmed.

 

3. Lifestyle and weight gain

It is important to emphasize that weight gain is primarily influenced by lifestyle factors. Poor lifestyle habits, including an unbalanced diet, lack of physical exercise, and irregular sleep patterns, are much more likely to lead to weight gain than melatonin intake itself. Eating habits play a major role in weight management and physical exercise remains a key factor in maintaining a healthy metabolism.

Melatonin itself cannot be considered a trigger for weight gain. On the contrary, improved sleep quality due to melatonin could be beneficial for weight management by improving hormonal regulation, particularly regarding hunger hormones. This can help individuals better control their food cravings and avoid overeating, especially in the evening.

It should also be noted that research shows that lack of sleep is linked to increased weight gain, particularly due to the disruption of ghrelin and leptin levels. Therefore, by allowing deeper and more restful sleep, melatonin can help restore this hormonal balance and, indirectly, prevent weight gain.


Melatonin, when used correctly, is not directly linked to weight gain. On the other hand, its positive impact on sleep and the regulation of hunger hormones can indeed help better manage appetite and avoid nocturnal snacking, which could prevent excessive weight gain. However, high and prolonged doses of melatonin could potentially have negative effects on metabolism in rare cases. Ultimately, weight gain depends much more on lifestyle habits, such as a balanced diet and physical exercise, than on the use of melatonin itself. As with any supplement, it is important to consult a healthcare professional before incorporating melatonin into your routine, especially if you have concerns about weight management.

 

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To learn more about its metabolic effects: Does melatonin cause fatigue the next day?

For its link with blood pressure: Does melatonin raise blood pressure?

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