The word “melatonin” itself evokes the thought of a cozy blanket, a quiet evening, and the soft descent into slumber. It’s nearly synonymous with sleep aids, a well-known go-to supplement for your restless nights and your jet lag recovery. But what if the melatonin’s story goes far beyond counting sheep?
While most people associate melatonin primarily with their sleep, this hormone also plays a vital role in another part of the body: the gut. Many melatonin users are unaware that it influences intestinal health just as much as it regulates sleep.
Did you know that a considerable amount of melatonin is produced not only in the brain but also in the gut? This localized synthesis suggests that melatonin plays a direct and significant role in promoting digestive health.
This article will discuss how melatonin is produced in the gut, how it affects IBS, and how it may help with stomach pain. It will also provide guidance on using melatonin safely and effectively, in a gut-friendly way.
Read More: Can Melatonin Supplements Harm Your Sleep Cycle Long-Term
What Is Melatonin—and Why the Gut Produces So Much of It
Although getting a good night’s sleep is crucial to our health, many of us find it challenging to do so. Your gut health may be the unexpected cause if you’re having trouble falling or staying asleep.
Melatonin, the hormone that controls our sleep-wake cycle, is intriguingly linked to our gut health, according to recent research. Our gut is home to trillions of bacteria, collectively known as the gut microbiome, which play a key role in maintaining a healthy digestive tract.
However, these bacteria also affect our sleep patterns. The gut microbiota affects several aspects of our overall health, including sleep, underscoring its impact beyond the digestive system.
One of the primary ways the gut microbiome regulates melatonin production is by synthesizing tryptophan, a very essential amino acid that serves as a precursor for melatonin. Certain gut bacteria contain the potential to convert tryptophan into serotonin, which can then be further turned into melatonin by the pineal gland.
The stomach, though, is also a key site of melatonin synthesis, with some studies revealing melatonin levels at least 400 times larger than in the pineal gland, another site of melatonin production.
The gut microbiota can alter the activity of the enzymes involved in melatonin production. Some gut bacteria enhance the activity of these enzymes, thereby increasing melatonin production. On the other hand, dysbiosis, an imbalance or disturbance in the gut microbiome, can hinder the body’s production of melatonin, which can lead to sleep disorders.
The Science Behind Melatonin’s Effect on IBS Symptoms

Sleep disturbance is typically observed in people with irritable bowel syndrome (IBS), occurring in 40%. The “bad bowels cause bad dreams” theory is supported by some research, even though the cause-and-effect relationship is unclear.
One such discovery is that IBS patients experience more rapid eye movement (REM) sleep, a period marked by arousal, than non-REM sleep. On the other hand, there is also evidence in favor of the opposite association, that the bowel disruption is a result of poor sleep rather than a cause of it.
The regulation of gastrointestinal motility, the local anti-inflammatory response, and the modulation of visceral sensation are all aspects of gastrointestinal physiology in which melatonin plays a significant role. Melatonin is usually given orally. The US Food and Drug Administration classifies it as a dietary supplement.
Melatonin medication has a considerable margin of safety, yet it may induce modest adverse effects, such as headache, rash, and nightmares. Many experts hail melatonin as a promising therapy option for IBS. Putative roles of melatonin in IBS treatment include analgesic effects, regulation of gastrointestinal motility, and sleep-promoting effects.
Read More: Why People Feel More Anxious in the Morning: Causes, Science & How to Stop It
What Research Says About Melatonin and IBS

Research indicates that the gastrointestinal tract also secretes melatonin, which has potent anti-inflammatory, antioxidant, and intestinal motility-regulating properties. All of these techniques increase the likelihood that melatonin will help IBS sufferers feel better.
Melatonin has been demonstrated to reduce smooth muscle motility, likely by stimulating specific receptors in the GI tract, modulating calcium-activated potassium channels in cells, and blocking nicotinic receptors.
Melatonin may also influence the gut’s visceral sensation. While the specific mechanism is uncertain, studies do demonstrate symptom alleviation in persons with IBS who take melatonin.
Potential Benefits and Risks
This section will examine the advantages and disadvantages of melatonin, emphasizing its ability to promote sleep, reduce anxiety, and alleviate specific pain, and the potential adverse effects some people may experience.
Benefits: Melatonin is well-known for helping people sleep, but it also has other benefits. This hormone can change shape, suggesting it has many biological functions and could benefit your health in many ways. Here are some other good things about melatonin:
Migraine and Headache Treatment: Melatonin may help if you get migraines or headaches a lot. A randomized clinical study found that taking 3 mg of melatonin daily cut the number of migraines in half compared with a placebo.
Reducing Anxiety Before Medical Treatments: Surgery and dentist visits are two examples of medical procedures that might make you anxious. Studies have shown that melatonin can help people relax and lower their stress levels before procedures, which can help ease anxiety.
Pain Relief: Melatonin’s anti-inflammatory properties may help ease pain in some cases. It may not be a potent pain reliever, but it may help with pain, especially inflammation-related pain.
Side Effects: While typically considered harmless, melatonin may induce modest adverse effects in some individuals, including:
- Headache
- Dizziness
- Nausea
- Daytime drowsiness
- Allergic Reaction
How to Use Melatonin Safely for IBS (If Recommended)

There are some ways to determine whether melatonin is safe and works as well as possible:
Professional Advice: Always talk to your doctor or a gastroenterologist before taking any supplements.
Best Time: For the best results, take melatonin 1–2 hours before bed to help control sleep and bowel movements.
Start Low: If you are sensitive to supplements, start with a smaller dose.
Lifestyle Integration: To get the most out of melatonin, you should also practice sleep-promoting habits, like maintaining a regular sleep schedule, eating a high-fiber diet, staying hydrated, and managing stress.
Conclusion
Melatonin is not merely a sleep hormone. The gut produces it in significant quantities, helping regulate inflammation, pain, and digestion. For patients with IBS, this is significant. Melatonin may help relieve stomach pain, cramping, and bloating. Additionally, it might promote more regulated bowel movements and a healthier intestinal lining.
Melatonin, however, does not treat IBS. Its effects vary from person to person, especially depending on whether they have IBS with diarrhea or constipation. That is why you should talk to a doctor before using it.
References
- Faghih Dinevari, M., Jafarzadeh, F., Jabbaripour Sarmadian, A., Abbasian, S., Nikniaz, Z., & Riazi, A. (25 April 2023). The effect of melatonin on irritable bowel syndrome patients with and without sleep disorders: A randomized double‑blinded placebo‑controlled trial study.
- St. John Fisher University. A Review of the Role of Melatonin in Irritable Bowel Syndrome.
- SupplySide. (2005, June 20). Melatonin eases IBS pain.
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