Is Melatonin Bad for Your Liver? Its Safety in Liver Function

If you’re concerned about how melatonin might affect your liver, you’re not alone. Many people share this concern when trying to improve their sleep quality. So is melatonin bad for your liver? The good news is that it is generally considered safe for your liver. This naturally-occurring hormone supplement is widely used to support better sleep. Clinical studies show no evidence that melatonin causes liver injury. In fact, new research suggests that it may even help the liver from various conditions.

What is Melatonin and How Does It Work?

Melatonin is a natural hormone that your brain makes. Your pineal gland produces this hormone to control your sleep-wake cycle. When it gets dark, the body releases this hormone in higher amounts to make you feel sleepy. When the sun is up, melatonin levels drop to help you wake up.

Many people take melatonin supplements to sleep better without needing any prescription. In 2012 alone, about 3 million Americans are using this supplement as natural sleep aid. You can find these supplements in most pharmacies and health stores.

Key Facts about Melatonin

• Your body naturally makes 18.5-180 pg/ml that peaks at 3AM

• Supplement doses typically range from 0.1-0.3mg/d low doses

• It works best when taken 30 minutes to 2 hours before bedtime

• The hormone helps reset your internal clock during jet lag or shift work

Melatonin also works as a powerful antioxidant in your body. This means that it can protect your cells from harmful substances like free radicals. Your liver particularly benefits from antioxidants because its function is to process toxins and medications (if you’re taking it).

The supplement form of melatonin is synthetic, which means that the laboratory manufactures it and extracts it from animals. The synthetic version works similar to the natural melatonin. It is considered as a regulated supplement by the Food and Drug Administration (FDA). It does not serve as a medication.

How melatonin affects your body:

• Binds to melatonin receptors in your brain

• Reduces the time it takes to fall asleep

• May improve sleep quality and duration

• Helps regulate circadian rhythms

• Provides antioxidant protection to organs including the liver

There is growing evidence that melatonin has anti-inflammatory and antioxidant properties beyond the sleep benefits you may get. Having these properties can help protect your liver from oxidative stress and inflammation rather than damaging it.

Can Melatonin Cause Liver Damage?

No, there is no evidence that melatonin, when used properly as advised, causes liver damage. It earned a hepatotoxic score of E, which means it is highly unlikely to cause any liver injury.

There may be some minor side effects of melatonin intake but liver damage isn’t one of them. These effects are mild and usually go away once you adjust to the supplement.

Common melatonin side effects (not liver-related):

• Daytime drowsiness or grogginess

• Headaches

• Dizziness

• Nausea or stomach discomfort

• Vivid dreams or nightmares

• Mood changes like irritability

There are also other people who worry about drug interactions with melatonin. This supplement interacts with medication like blood thinners. But these interactions don’t typically affect your liver. However, this may change how the medications work and perhaps would increase bleeding risk.

Medications that may interact with melatonin:

• Blood thinners like warfarin

• Diabetes medications

• Blood pressure medications

• Sedatives and sleep medications

• Some antidepressants

You should always consult your doctor before you start melatonin. Always disclose any medication that you are taking. This is a necessary precaution to ensure your safety but isn’t specifically about liver protection.

The safety profile of melatonin remains excellent even with long-term use. Numerous studies did not reveal any liver injury after melatonin use. It did not also increase the risk of liver problems compared to people who don’t take melatonin.

What Do Studies Say About Melatonin and Liver Injury?

Clinical trials done consistently show that melatonin does not cause harm to your liver. In fact, medical journals talk about its protective effects and its safety. The majority of the studies revolve around melatonin and its effects on liver enzymes. Nonetheless, there has been no established evidence that it can increase liver enzymes.

Key research findings:

• No liver enzyme elevations reported in clinical trials

• Liver function tests remain normal during melatonin treatment

• Long-term studies show no increased liver injury risk

• High-dose melatonin doesn't cause liver toxicity

A study worth noting is the use of melatonin in patients who are about to undergo major surgery. It was found that patients who had melatonin treatment had shorter ICU and total hospital stay. Instead of causing harm, it actually helped the patients recover post-surgery.

Liver enzymes are often used as tools for determining liver health. This includes ALT (alanine transaminase) and AST (aspartate aminotransferase) enzymes. Often, these enzymes increase in the blood when there is liver damage. Body melatonin was shown to be increased in response to liver damage as a regulatory hormone.

Liver enzyme findings in melatonin studies:

• ALT levels remain within normal ranges

• AST levels show no significant increases

• Some studies report improved enzyme profiles

• No cases of drug-induced liver injury documented

These researches span different populations, from healthy adults to people with underlying medical issues like sleep disorders and hypercholesterolemia. Across all these groups, liver safety remains consistent. The broad evidence base supporting melatonin strengthens the claim that melatonin does not cause harm to the liver.

Are There Any Reported Cases of Liver Damage from Melatonin?

No, there were no reported cases of liver damage from melatonin intake, isolated or otherwise. In numerous studies and literature, there has been no evidence that intake of the supplement causes liver damage. Even serious adverse effects are rare, occurring in just 0.1% of people.

The few side effects reported were minor and unrelated to liver function. The safety monitoring systems have been tracking supplements and medications for adverse events. These systems have not identified melatonin as the cause of any liver injury or problem. This absence of reports is significant given melatonin's widespread use across millions of people.

Why liver damage cases are unlikely:

• Melatonin doesn't undergo significant liver metabolism

• The supplement has a short half-life in your body

• Your liver naturally produces and processes melatonin

• No toxic metabolites are created during breakdown

If you have an existing liver problem, it is understandable that you’d worry about taking any supplements. While it is prudent to exercise caution, melatonin has proven to be safe across different populations. But medical supervision is still recommended for people with serious liver conditions.

The lack of documented or isolated cases of liver damage in decades made this supplement safe. The excellent safety record offers reassurance that people can use melatonin supplements for its beneficial effects. However, individual responses are varied, which means you have to discuss with your doctor if you wish to use this supplement.

Are There Any Benefits of Melatonin for Liver Health?

Yes, there is evidence that melatonin has beneficial effects on liver health. Some studies link melatonin use to improvements in conditions like non-alcoholic fatty liver disease (NAFLD). It was shown that melatonin actually helps in liver function. These benefits likely come from melatonin’s antioxidant and anti-inflammatory properties.

A trial found that people taking 6 mg of melatonin for 12 weeks offered significant improvements to NAFLD. It also led to improvements in fatty liver grades on imaging studies. The improvements suggest that melatonin therapy may actually reverse liver damage, not cause it.

Potential liver health benefits:

• Reduced inflammation in liver cells

• Improved fat metabolism in the liver

• Lower oxidative stress levels

• Better liver enzyme profiles

• Possible protection against liver scarring

The antioxidant effects of melatonin are particularly important for liver health. Your liver processes toxins, medications, and waste products daily. This constant work creates oxidative stress, which can damage liver cells over time.Melatonin's antioxidant properties help neutralize harmful free radicals.

How melatonin supports liver function:

• Scavenges harmful free radicals

• Reduces cellular inflammation

• Supports natural detoxification processes

• May improve insulin sensitivity

• Helps regulate fat storage in liver cells

Current research focuses on melatonin's role in fatty liver disease, the most common liver condition in developed countries. Early results are encouraging, but researchers need more studies to confirm these benefits. The existing evidence suggests melatonin is not only safe for your liver but might actually help protect it.

Melatonin was also studied on its effects on alcoholic liver disease and other liver disease. However, the investigations are still recent and substantial evidence must be collected yet. Nonetheless, there is a consistent pattern in melatonin’s protective effect.

How Does Melatonin Help in NAFLD?

There are several mechanisms that melatonin helps NAFLD, targeting the root cause of the disease. NAFLD is a result of fat buildup in liver cells, which causes inflammation and potential scarring if left untreated. Melatonin deals with both fat accumulation and inflammation.

Melatonin's mechanisms in NAFLD:

• Reduces oxidative stress in liver cells

• Improves insulin sensitivity

• Enhances fat metabolism

• Decreases inflammatory markers

• May prevent liver scarring progression

Melatonin treats the underlying cause, which may progress and worsen NAFLD. In essence, melatonin as a supplement is considered protective against liver diseases.

Experts leading these scientific studies believe that taking melatonin supplements at the right time can help align your body’s natural rhythm. This will optimize melatonin’s effect, which can enhance its beneficial effects on liver metabolism and reduce inflammation.

Can Melatonin Protect the Liver from Other Damages?

Yes, like mentioned earlier, melatonin is recently being studied for other liver problems. The results have been promising and consistent in offering beneficial liver effects.

It has been used before surgical procedures, which has been discussed previously, resulting in shorter ICU or total hospital stay. Melatonin has also shown promise in reducing ischemia-reperfusion injury (an injury when blood flow suddenly returns to a tissue after it has been blocked), which is a common issue faced in interventional cardiology. However, there are still no major conclusions drawn from studies of its use in this manner.

Types of liver protection studied:

• Alcoholic liver disease prevention

• Surgical liver injury reduction

• Drug-induced liver damage protection

• Viral hepatitis inflammation control

• Age-related liver function decline

Compared to other sleep supplements, melatonin offers a superior safety profile for liver health. Melatonin avoids liver stress during metabolism, making it a safer choice for people who want to get some good night’s sleep but are worried about liver health.

Animal studies have been extensive for melatonin. But human studies are catching up and underway. It won’t be long before evidence of melatonin’s protective benefits can be proven. Nonetheless, despite this positive promise, it is still prudent to exercise caution.

Melatonin’s beneficial effects have been drawn from its anti-inflammatory and antioxidant properties. In addition, the way it helps regulate sleep-wake cycle can also benefit individuals with poor sleep quality. This dual effect makes it an attractive option if you want to regulate sleep and protect your liver at the same time.

Who Should Avoid Melatonin Due to Liver Concerns?

The majority of people can take melatonin without any worries. However, certain groups of people should maintain necessary precautions. Even with melatonin’s safety profile, you need to talk to your doctor before starting the supplement. Limited evidence and data exists for people who already have liver disease in the first place.

While it may be beneficial for some liver conditions like NAFLD, you should always take precaution when you have advanced liver disease. This does not mean melatonin could be dangerous for you. But studies are yet to be done to establish its use in this particular group.

Groups who should consult a doctor first:

• People with chronic liver disease

• Those taking blood thinning medications

• Individuals on multiple prescription drugs

• People with severe liver cirrhosis

• Anyone with a history of liver transplant

Like mentioned, melatonin may interact with blood thinners. This could mean that you are likely to be at increased risk for bleeding. It does not directly affect liver health but it is one of the most important precautions to note.

Your doctor should be able to assess your risk and determine whether melatonin is appropriate for you. Openly discuss with them your current medical conditions, any medications you are taking, and overall medical history. This could lead to a more personalized and tailored approach to ensure the safest possible way that you can take melatonin.

Even people without liver disease should follow proper dosing guidelines. Taking more melatonin doesn't necessarily improve sleep and may increase side effect risk. Starting with the lowest effective dose and increasing gradually under medical guidance is the safest approach.

Quick Summary Box

• Melatonin is safe for your liver and does not cause liver damage

• Research shows melatonin may help liver conditions like NAFLD by reducing inflammation

• Studies found improved liver enzymes with 6mg daily melatonin

• People with liver disease should talk to their doctor before using melatonin

• All studies show melatonin protects rather than harms liver tissue

Frequently Asked Questions

Can I take melatonin if I have a history of liver disease?

The best answer is to consult your doctor. Limited data exists for the use of melatonin in patients with liver problems, particularly if severe. While melatonin appears safe, medical supervision is recommended for people with liver conditions to ensure personalized safety.

Does melatonin interact with liver medications?

Yes, melatonin may interact with medications. These interactions typically don't affect the liver directly but can change how medications work.

Is there a safe dosage for liver health?

Studies suggest 6-10 mg/day is safe, but consult a doctor for liver conditions. Starting with lower doses and increasing gradually under medical guidance provides the safest approach.

Related Resources

Does Smoking Affect Your Liver? Here’s What You Should Know

What Part of the Body Itches with Liver Damage? Evidence-Based Guide

References

References

Aulinas, A., & Arendt, J. (2022). Physiology of the Pineal Gland and Melatonin. PubMed; MDText.com, Inc. https://www.ncbi.nlm.nih.gov/books/NBK550972/ 

Bahrami, M., Cheraghpour, M., Jafarirad, S., Alavinejad, P., Asadi, F., Hekmatdoost, A., Mohammadi, M., & Yari, Z. (2020). The effect of melatonin on treatment of patients with non-alcoholic fatty liver disease: a randomized double blind clinical trial. Complementary Therapies in Medicine, 52, 102452. https://doi.org/10.1016/j.ctim.2020.102452 

Bermudez-Gonzalez, J. L., Sanchez-Quintero, D., Proaño-Bernal, L., Santana-Apreza, R., Jimenez-Chavarria, M. A., Luna-Alvarez-Amezquita, J. A., Straface, J. I., Perez-Partida, A. M., Berarducci, J., Armenta-Moreno, J. I., Garza-Cruz, K. J., Espinola-Zavaleta, N., & Alexanderson-Rosas, E. (2022). Role of the Antioxidant Activity of Melatonin in Myocardial Ischemia-Reperfusion Injury. Antioxidants (Basel, Switzerland), 11(4), 627. https://doi.org/10.3390/antiox11040627 

Che, Z., Song, Y., Xu, C., Li, W., Dong, Z., Wang, C., Ren, Y., So, K.-F., Tipoe, G. L., Wang, F., & Xiao, J. (2022). Melatonin alleviates alcoholic liver disease via EGFR–BRG1–TERT axis regulation. Acta Pharmaceutica Sinica B, 13(1), 100–112. https://doi.org/10.1016/j.apsb.2022.06.015 

Chitimus, D. M., Popescu, M. R., Voiculescu, S. E., Panaitescu, A. M., Pavel, B., Zagrean, L., & Zagrean, A.-M. (2020). Melatonin’s Impact on Antioxidative and Anti-Inflammatory Reprogramming in Homeostasis and Disease. Biomolecules, 10(9), 1211. https://doi.org/10.3390/biom10091211 

D. Terziev, & Terzieva, D. (2023). Experimental Data on the Role of Melatonin in the Pathogenesis of Nonalcoholic Fatty Liver Disease. Biomedicines, 11(6), 1722–1722. https://doi.org/10.3390/biomedicines11061722 

John Hopkins Medicine. (2012). Melatonin for Sleep: Does It Work? Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/wellness-and-prevention/melatonin-for-sleep-does-it-work 

Mansoori, A., Salimi, Z., Hosseini, S. A., Hormoznejad, R., Jafarirad, S., Bahrami, M., & Asadi, M. (2020). The effect of melatonin supplementation on liver indices in patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis of randomized clinical trials. Complementary Therapies in Medicine, 52, 102398. https://doi.org/10.1016/j.ctim.2020.102398 

Mayo Clinic. (2021, September 22). Nonalcoholic fatty liver disease - symptoms and causes. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/nonalcoholic-fatty-liver-disease/symptoms-causes/syc-20354567 

Melatonin. (2020, January 10). Nih.gov; National Institute of Diabetes and Digestive and Kidney Diseases. https://www.ncbi.nlm.nih.gov/books/NBK548519/ 

NCCIH. (2024, May). Melatonin: What you need to know. National Center for Complementary and Integrative Health. https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know 

NHS. (2023, February 23). Side Effects of Melatonin. Nhs.uk. https://www.nhs.uk/medicines/melatonin/side-effects-of-melatonin/ 

Nickkholgh, A., Schneider, H., Sobirey, M., Venetz, W. P., Hinz, U., Pelzl, L. H., Gotthardt, D. N., Cekauskas, A., Manikas, M., Mikalauskas, S., Mikalauskene, L., Bruns, H., Zorn, M., Weigand, M. A., Büchler, M. W., & Schemmer, P. (2011). The use of high-dose melatonin in liver resection is safe: first clinical experience. Journal of Pineal Research, 50(4), 381–388. https://doi.org/10.1111/j.1600-079X.2011.00854.x 

Savage, R. A., Basnet, S., & Miller, J.-M. M. (2020, October 23). Melatonin. Nih.gov; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK534823/ 

Sohrabi, M., Gholami, A., Taheri, M., Fekri, S., Bahare Amirkalali, Hatami, S., Marzieh Hajbaba, Hamid Fallah Tolbar, Aghili, S., Zamani, F., Mohsen NasiriToosi, & Hossein Keyvani. (2021). Melatonin Levels in Patients with Nonalcoholic Fatty Liver Disease Compared with Healthy Individuals according to Fibrosis Level. Middle East Journal of Digestive Diseases./Middle East Journal of Digestive Diseases, 13(2), 109–114. https://doi.org/10.34172/mejdd.2021.213 

Terzieva, D. D., Mateva, N. D., & Vladimirova-Kitova, L. G. (2009). Melatonin reference limits at 3:00 AM and 8:00 AM in healthy adults. Clinical Laboratory, 55(9-10), 359–361. https://pubmed.ncbi.nlm.nih.gov/20099572/ 

White, E. (2023, August 21). 9 Melatonin Interactions to Be Aware of Before Taking It. GoodRx; GoodRx. https://www.goodrx.com/melatonin/interactions 

Zhang, J.-J., Meng, X., Li, Y., Zhou, Y., Xu, D.-P., Li, S., & Li, H.-B. (2017). Effects of Melatonin on Liver Injuries and Diseases. International Journal of Molecular Sciences, 18(4). https://doi.org/10.3390/ijms18040673