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Does Melatonin Break a Fast?

It’s common for people to take dietary supplements to stay healthy during intermittent fasting, as they can ensure you get enough nutrients and help improve different areas of your lifestyle, like sleep and energy levels.

One of the most popular supplements among fasting people is melatonin. Although our bodies already make melatonin, supplementation can improve overall sleep quality, making it easier to fall asleep and rest well throughout the night.

But can you take melatonin supplements during your fasting window? Find out in this article.

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What Is Melatonin—And How Does It Help With Insomnia?

Melatonin is a natural hormone responsible for sleep-wake cycles and the timing of the circadian rhythm—the body’s biological clock.

Although our bodies produce melatonin naturally, some people use supplements to relieve certain sleep disorders, such as insomnia and irregular sleep patterns. These supplements may also help relieve symptoms of jet lag and shift work.

Melatonin is especially important for people who practice intermittent fasting. Let’s look at how this eating pattern can cause trouble sleeping.

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Insomnia and intermittent fasting

Many people use time-restricted eating as a way to reset their circadian rhythm and sleep better. However, this strategy may not work on everyone, especially during the first days of fasting, while your body adapts to this new routine:

  • Fasting may cause your natural melatonin levels to drop. Since this hormone is responsible for sleep quality, you may experience insomnia and general sleep problems.
  • Restricting calories can increase cortisol (stress hormone) levels. Excessive cortisol can make you feel anxious and awake at night, contributing to sleep deprivation.

Additionally, eating at irregular times can cause fluctuations in body temperature, mood, and digestion—changes that may also disrupt your sleep at night.

Whether fasting or not, taking melatonin supplements can help you get back to a healthy sleep cycle. Synthetic melatonin, while not FDA-approved, is often used as a first-line treatment for insomnia.

Does Melatonin Break a Fast?

Consuming any amount of calories during the fasting window technically breaks the fast, as calories trigger an insulin response. However, certain products, like calorie-free beverages, black coffee, and tea, are permitted even during your fasting period since they do not have any calories.

Some supplements may break your fast, depending on their nutritional content. Melatonin, however, has no nutritional value. It is calorie-free and contains no fats, proteins, or carbohydrates. As a result, it does not provoke an insulin response, which means that melatonin does not break the fast and can be taken without concern during the fasting window.

How about melatonin gummies?

Now, you’re probably wondering—will melatonin gummies break a fast?

Melatonin gummies typically contain artificial flavors, sugar, and other sweeteners to enhance the taste. Due to the presence of sugar and other ingredients, gummies usually contain calories and carbs.

Although they taste good, gummies will likely raise your insulin levels and break your fast. 

Of course, certain brands offer sugar-free melatonin gummies. However, you must always read the label carefully to ensure all ingredients are safe and that they don’t contain any added sugars.

If you want to succeed with intermittent fasting, it’s best to play it safe and stick to melatonin pills.

4 Benefits of Taking Melatonin While Fasting

Melatonin has many benefits that may improve your overall health and well-being, especially if you’re fasting. This supplement is worth adding to your routine as it doesn’t break the fast.

Let’s dig into the top 4 benefits of melatonin supplements.

1. Supports good quality sleep

Melatonin has been shown to improve sleep habits, helping you relax and prepare for a good night’s rest.

Studies indicate that melatonin supplements can improve sleep quality and address circadian rhythm disturbances in patients with insomnia. Even small doses taken before bedtime promote healthy sleep cycles in individuals with delayed sleep-wake phase disorder (DSWPD).

Obtaining sufficient quality sleep is essential to maintaining energy and staying active throughout the day, particularly if you practice intermittent fasting.

2. Helps you feel full of energy

Intermittent fasting increases energy levels in the long run. However, it is normal to feel tired and sluggish as your body gets used to abstaining from food, especially during the first days.

Taking melatonin can aid in achieving quality sleep, which in turn helps you maintain energy during fasting periods.

Aside from promoting sleep, melatonin can also:

These benefits not only help you feel more energized and active, but they also contribute to weight loss.

3. Reduce symptoms of seasonal depression

Sunlight plays a critical role in melatonin production and circadian rhythms, which means that seasonal light changes significantly impact the quality of our sleep, often leading to seasonal affective disorder (SAD) or seasonal depressive disorder.

Because melatonin helps regulate the internal clock, it may also reduce symptoms associated with seasonal depression.

4. May help in the treatment of GERD

Research shows that melatonin may help treat gastroesophageal reflux disease (GERD) by inhibiting gastric acid secretion.

Sleep disturbances are closely related to GERD, but good sleep quality can support treatment and also improve symptoms.

Does Melatonin Cause Any Side Effects?

Melatonin is generally well-tolerated, but like any other synthetic supplement, it may cause adverse effects.

Common side effects of short-term melatonin use include:

If you’re unsure how melatonin affects you, consult your doctor and seek medical supervision before taking it or trying other over-the-counter medications.

How to Use Melatonin Properly

Taking melatonin correctly is crucial to minimize the risk of adverse effects. Consider the following tips to get the best results from your fasting experience.


When using melatonin to aid sleep, it’s best to take it up to two hours before bedtime. Once you’ve taken your pills, remember to avoid screens and engage in relaxing activities to ease your way into a restful sleep.

Taking melatonin on an empty stomach

This supplement is more effectively absorbed when taken on an empty stomach. If melatonin causes side effects like stomach cramps or discomfort, put a heating pad on your stomach area to help alleviate them.


Melatonin pills are available over the counter in doses ranging from 1 to 10 milligrams and higher. Although there is no official recommendation for intermittent fasting, a melatonin dose between 0.5 and 5 milligrams is effective for healthy adults.

The correct dosage can vary from person to person. For safety, always follow the recommendations on the medicine package.

DoFasting Makes Fasting Easy

Intermittent fasting is a great practice that can positively transform your life. People fast for therapeutic and medical reasons, to promote fat burning for weight loss, and to improve overall health. This eating habit involves limiting food intake to designated eating windows to lead the body into a state of ketosis, in which it burns stored fat for fuel.

If you’ve never fasted before, you can begin with the 12:12 fast, in which you abstain from food for 12 hours and are allowed to eat for another 12 hours. Once your body adapts, you can progress to more advanced fasting methods like the 16:8 and 14:10 plans.

Before jumping into your first intermittent fasting adventure, consider using the DoFasting app. It includes fasting tips, expert guidance, trackers, recipes, and recommended exercises—everything you need for a smooth fasting experience in one convenient app.

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So, does melatonin break a fast?

Taking melatonin pills won’t break a fast, as they don’t contain calories or nutrients that would raise your insulin levels. You can continue to enjoy the health benefits of intermittent fasting and achieve the best results for weight loss.

Remember that liquid or gummy forms of melatonin may contain sugar and other additives that can break your fast. To get the best benefits, opt for the pill form of melatonin.


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This is an evidence-based article that includes scientific citations. DoFasting’s professional writers and editors prepared the content, which a team of medical experts verified to be accurate.

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