Drug & supplement interaction

Melatonin + Gemcitabine

Gemcitabine brand name: Gemzar.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between Melatonin and Gemcitabine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Melatonin and Gemcitabine

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Gemcitabine and Melatonin in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Melatonin safety at a glance

Melatonin overall Use caution Generally well tolerated for short-term use, but long-term safety is less certain and product quality varies.

Pregnancy Possibly Unsafe When used orally or parenterally in high doses or with frequent use. High doses of melatonin 75-300 mg daily seem to inhibit ovulation, causing a contraceptive... Read the full pregnancy detail

Breastfeeding Avoid Safety while breastfeeding has not been established, so avoid unless directed by your doctor.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Gemcitabine and Melatonin? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Gemcitabine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Gemcitabine is filed under 2 classifications — antineoplastics, hepatotoxic drugs. Melatonin has documented interactions with 18 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), anticonvulsants (moderate) and antidiabetes drugs (moderate) — and none of Gemcitabine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Melatonin Does Interact With Other Medications

Melatonin has 1,116 moderate, 345 minor known drug interactions in our database — Gemcitabine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 1,116 Minor 345 No known interaction 1,369 (incl. Gemcitabine)

Taking anything else?

Check Another of Your Medications Against Melatonin

Covers the 2,830 medications we’ve checked against Melatonin. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Melatonin and Gemcitabine May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

Liver problems Worth acting on Additional detail
Melatonin
“A case of autoimmune hepatitis has been reported for a patient who took melatonin orally to treat insomnia. Melatonin use has also been linked to a few cases of Gilbert's syndrome.”

Melatonin · Natural Medicines adverse-effect record, reported in hepatitis.
2 sources cited

63037. Hong, Y. G. and Riegler, J. L. Is melatonin associated with the development of autoimmune hepatitis? J Clin Gastroenterol 1997;25(1):376-378. PubMed

114510. Ha M, Yoon D, Lee CY, et al. Investigating the safety profiles of exogenous melatonin and associated adverse events: A pharmacovigilance study using WHO-VigiBase. J Pineal Res 2024;76(2):e12949. PubMed
Gemcitabine

Listed in the ADVERSE REACTIONS section of the FDA label for Gemcitabine. Read the label on DailyMed ›
A skin rash Additional detail
Melatonin
“Papular skin rash and pruritus has been reported with melatonin use. However, the effect was generally mild and did not require cessation of melatonin treatment, and had similar rates as placebo. Cutaneous flushing, angiokeratoma, and nasal mucosal ulcers have also been reported.”

Melatonin · Natural Medicines adverse-effect record, reported in jet lag.
6 sources cited

62450. van der Heijden, K. B., Smits, M. G., van Someren, E. J., Ridderinkhof, K. R., and Gunning, W. B. Effect of melatonin on sleep, behavior, and cognition in ADHD and chronic sleep-onset insomnia. J Am Acad.Child Adolesc.Psychiatry 2007;46(2):233-241. PubMed

62754. Elkhayat, H. A., Hassanein, S. M., Tomoum, H. Y., Abd-Elhamid, I. A., Asaad, T., and Elwakkad, A. S. Melatonin and sleep-related problems in children with intractable epilepsy. Pediatr.Neurol. 2010;42(4):249-254. PubMed

109696. Yan W, Li C, Song X, Zhou W, Chen Z. Prophylactic melatonin for delirium in critically ill patients: A systematic review and meta-analysis with trial sequential analysis. Medicine (Baltimore) 2022;101(43):e31411. PubMed

96316. Gonçalves AL, Martini Ferreira A, Ribeiro RT, Zukerman E, Cipolla-Neto J, Peres MF. Randomised clinical trial comparing melatonin 3 mg, amitriptyline 25 mg and placebo for migraine prevention. J Neurol Neurosurg Psychiatry 2016;87(10):1127-32. PubMed

62770. van Geijlswijk, I. M., van der Heijden, K. B., Egberts, A. C., Korzilius, H. P., and Smits, M. G. Dose finding of melatonin for chronic idiopathic childhood sleep onset insomnia: an RCT. Psychopharmacology (Berl) 2010;212(3):379-391. PubMed

62914. Papavasiliou, P. S., Cotzias, G. C., Duby, S. E., Steck, A. J., Bell, M., and Lawrence, W. H. Melatonin and parkinsonism. JAMA 7-3-1972;221(1):88-89. DOI
Gemcitabine

Listed in the ADVERSE REACTIONS section of the FDA label for Gemcitabine. Read the label on DailyMed ›
Nausea reported in 4.9% of FDA reports for Gemcitabine Additional detail
Melatonin
“Orally, melatonin may cause nausea, abdominal cramps, or mild abdominal pain, diarrhea, constipation, or decreased appetite. Often these symptoms occur during the first few days of treatment and subside after a few days. In some cases, rates of symptoms are similar between melatonin and placebo.”

Melatonin · Natural Medicines adverse-effect record, reported in constipation.
6 sources cited

62384. Buscemi, N., Vandermeer, B., Pandya, R., Hooton, N., Tjosvold, L., Hartling, L., Baker, G., Vohra, S., and Klassen, T. Melatonin for treatment of sleep disorders. Evid.Rep.Technol.Assess.(Summ.) 2004;(108):1-7.

62770. van Geijlswijk, I. M., van der Heijden, K. B., Egberts, A. C., Korzilius, H. P., and Smits, M. G. Dose finding of melatonin for chronic idiopathic childhood sleep onset insomnia: an RCT. Psychopharmacology (Berl) 2010;212(3):379-391. PubMed

114510. Ha M, Yoon D, Lee CY, et al. Investigating the safety profiles of exogenous melatonin and associated adverse events: A pharmacovigilance study using WHO-VigiBase. J Pineal Res 2024;76(2):e12949. PubMed

62450. van der Heijden, K. B., Smits, M. G., van Someren, E. J., Ridderinkhof, K. R., and Gunning, W. B. Effect of melatonin on sleep, behavior, and cognition in ADHD and chronic sleep-onset insomnia. J Am Acad.Child Adolesc.Psychiatry 2007;46(2):233-241. PubMed

62754. Elkhayat, H. A., Hassanein, S. M., Tomoum, H. Y., Abd-Elhamid, I. A., Asaad, T., and Elwakkad, A. S. Melatonin and sleep-related problems in children with intractable epilepsy. Pediatr.Neurol. 2010;42(4):249-254. PubMed

62914. Papavasiliou, P. S., Cotzias, G. C., Duby, S. E., Steck, A. J., Bell, M., and Lawrence, W. H. Melatonin and parkinsonism. JAMA 7-3-1972;221(1):88-89. DOI
Gemcitabine

Listed in the ADVERSE REACTIONS section of the FDA label for Gemcitabine, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Melatonin but not commonly for Gemcitabine: dependence or withdrawal symptoms, drowsiness, reduced appetite and stomach pain.

Effects for Gemcitabine come from the ADVERSE REACTIONS section of its FDA label; effects for Melatonin come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 53,020 voluntary FDA FAERS reports for Gemcitabine that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Melatonin in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally or parenterally in high doses or with frequent use. High doses of melatonin 75-300 mg daily seem to inhibit ovulation, causing a contraceptive effect. Advise pregnant patients and patients wishing to become pregnant to avoid using melatonin frequently or in high doses. There is insufficient reliable information available about the safety of melatonin in lower doses during pregnancy. Some research shows that taking melatonin 2 mg daily does not affect anterior pituitary hormone levels in females who are not pregnant; this suggests that low doses may not have a contraceptive effect. Other research shows that taking melatonin 3 mg daily during the follicle stimulating stage of in vitro fertilization does not negatively impact pregnancy rates. However, it is not known if melatonin is safe for use throughout pregnancy. Until more is known about the safety of melatonin, avoid using during pregnancy.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Melatonin or Gemcitabine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Melatonin or Gemcitabine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Gemcitabine

This page covers Melatonin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Gemcitabine page lists 39 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Siberian Cocklebur (major), Wine (major), Ashwagandha (moderate) and Black Cohosh (moderate).

By severity: 3 major · 35 moderate · 1 minor.

Open the Gemcitabine interaction page

One more smart check

Taking Melatonin as Part of a Dietary Supplement Product? Check It for Interactions

We hold 2,885 real supplement products containing Melatonin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Melatonin. Even though Melatonin itself has no known interaction with Gemcitabine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Melatonin and Gemcitabine Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Melatonin

Top 5%

#55 of 1,452 supplements looked up here in the last 7 days

29 days ago today

Medication Gemcitabine

Steady interest

#2,169 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?

Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Melatonin reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Melatonin and Gemcitabine records this page draws on were last updated July 11, 2026.
What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.

Data structure & sourcing designed and verified by Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Melatonin

What is Melatonin?

Trouble falling asleep (insomnia)
Jet lag
Delayed sleep phase syndrome
Non-24-hour sleep-wake disorder
Shift-work sleep problems
Sleep problems in some children with conditions like autism or ADHD

Melatonin is a hormone your body makes naturally to help control your sleep-wake cycle, and the supplement form is widely used to help with sleep timing problems and jet lag. The evidence is strongest for certain circadian (body-clock) disorders and is more mixed for everyday insomnia. It is generally well tolerated for short-term use, but talk with your pharmacist or doctor before starting, especially for children or during pregnancy.

Hormone naturally made by the pineal gland; supplements are usually made synthetically · Tablets, capsules, gummies, sublingual (under-the-tongue) tablets, liquids, extended-release tablets

An interaction check asks whether these two react with each other — it does not ask whether Melatonin is a good idea for someone in your situation. Here is what our Melatonin record says about it on its own.

Melatonin: dosing

There is no single standardized dose of melatonin, and products vary widely in strength. Many people find that lower doses work as well as higher ones, and taking more does not always help more. Timing often matters as much as the amount, so for sleep timing problems and jet lag it is usually taken in the evening or before bedtime.The best approach is to follow the directions on the product label and start with the lowest amount that helps.

From our Melatonin monograph — the full record covers uses, side effects and every documented interaction.

Read the full Melatonin monograph & all interactions

Medication

About Gemcitabine Injection

What Is Gemcitabine Injection Used For?

Brand name: Gemzar

Gemcitabine Injection (available as Avgemsi, Gemcitabine, and Infugem) is used to treat several types of cancer. It is given in combination with carboplatin for advanced ovarian cancer that has returned at least 6 months after platinum-based treatment, and in combination with paclitaxel as a first-line treatment for metastatic breast cancer after prior chemotherapy with an anthracycline (a specific class of chemo drug).

It is also given in combination with cisplatin for non-small cell lung cancer (NSCLC) that cannot be removed surgically or has spread. For pancreatic cancer that is locally advanced or has spread, it is used as a single agent — including in patients who have already been treated with fluorouracil.

Most-Reported Side Effects for Gemcitabine

From FAERS, the FDA’s public side-effect reporting system (53,020 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Disease progression 4,850 reports

Thrombocytopenia 3,706 reports

Neutropenia 3,295 reports

Anemia 3,084 reports

Malignant neoplasm progression 2,912 reports

See full Gemcitabine Injection drug information

Keep checking

Other Drugs & Melatonin

Browse every other medication we’ve checked against Melatonin — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major

1,116Moderate

345Minor

1,368No known interaction

1,116 Moderate 345 Minor 1,368 No interaction

Moderate

1,116 interactions

Showing 60 of 1,116 moderate interactions — see all 1,116 on the Melatonin page.

Minor

345 interactions

Showing 60 of 345 minor interactions — see all 345 on the Melatonin page.

No interaction 1,368 drugs checked — show the list

We also checked Melatonin against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,368 medications checked with no known interaction — see the full Melatonin list.

See the full Melatonin interactions page

See every supplement checked against Gemcitabine, ranked by severity

Evidence & sources

Melatonin References

The 118 references that drive our Melatonin monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Voordouw BC, Euser R, Verdonk RE, et al. Melatonin and melatonin-progestin combinations alter pituitary-ovarian function in women and can inhibit ovulation. J Clin Endocrinol Metab 1992;74:108-17. DOI
Ellis CM, Lemmens G, Parkes JD. Melatonin and insomnia. J Sleep Res 1996;5:61-5. PubMed
Petrie K, Dawson AG, Thompson L, Brook R. A double-blind trial of melatonin as a treatment for jet lag in international cabin crew. Biol Psychiatr 1993;33:526-30. PubMed
Claustrat B, Brun J, David M, et al. Melatonin and jet lag: confirmatory result using a simplified protocol. Biol Psychiatr 1992;32:705-11.
Fauteck J, Schmidt H, Lerchl A, et al. Melatonin in epilepsy: first results of replacement therapy and first clinical results. Biol Signals Recept 1999;8:105-10. PubMed
Arangino S, Cagnacci A, Angiolucci M, et al. Effects of melatonin on vascular reactivity, catecholamine levels, and blood pressure in healthy men. Am J Cardiol 1999;83:1417-9. PubMed
Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
Lancioni GE, O'Reilly MF, Basili G. Review of strategies for treating sleep problems in persons with severe or profound mental retardation or multiple handicaps. Am J Ment Retard 1999;104:170-86. PubMed
Carman JS, Post RM, Buswell R, et al. Negative effects of melatonin on depression. Am J Psychiatry 1976;133:1181-1186. PubMed
Hartter S, Grozinger M, Weigmann H, et al. Increased bioavailability of oral melatonin after fluvoxamine coadministration. Clin Pharmacol Ther 2000;67:1-6.
Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.
Lusardi P, et al. Cardiovascular effects of melatonin in hypertensive patients well controlled by nifedipine: a 24-hour study. Br J Clin Pharmacol 2000;49:423-7. PubMed
von Bahr C, Ursing C, Yasui N, et al. Fluvoxamine but not citalopram increases serum melatonin in healthy subjects – an indication that cytochrome P450 CYP1A2 and CYP2C19 hydroxylate melatonin. Eur J Clin Pharmacol 2000;56:123-7.
Grozinger M, Hartter S, Wang X, et al. Fluvoxamine strongly inhibits melatonin metabolism in a patient with low-amplitude melatonin profile. Arch Gen Psychiatry 2000 Aug;57:812-3. PubMed
Lissoni P, Barni S, Mandala M, et al. Decreased toxicity and increased efficacy of cancer chemotherapy using the pineal hormone melatonin in metastatic solic tumor patients with poor clinical status. Eur J Cancer 1999;35:1688-92.
Sheldon SH. Pro-convulsant effects of oral melatonin in neurologically disabled children. Lancet 1998;351:1254. PubMed
Hartter S, Grozinger M, Weigmann H, et al. Increased bioavailability of oral melatonin after fluvoxamine coadministration. Clin Pharmacol Ther 2000;67:1-6.
Wright KP Jr, Myers BL, Plenzler SC, et al. Acute effects of bright light and caffeine on nighttime melatonin and temperature levels in women taking and not taking oral contraceptives. Brain Res 2000;873:310-7.
Herxheimer A, Petrie KJ. Melatonin for preventing and treating jet lag. Cochrane Database Syst Rev 2001;(1):CD001520.
Briggs, Freeman, Yafee. Update Drugs in Pregnancy and Lactation. Lippincott Williams & Wilkins, 2001.
Suhner A, Schlagenhauf P, Johnson R, et al. Comparative study to determine the optimal melatonin dosage form for the alleviation of jet lag. Chronobiol Int 1998;15:655-66. PubMed
Herxheimer A, Petrie KJ. Melatonin for the prevention and treatment of jet lag. Cochrane Database Syst Rev 2002;2:CD001520. PubMed
Munoz-Hoyos A, Sanchez-Forte M, Molina-Carballo A, et al. Melatonin's role as an anticonvulsant and neuronal protector: experimental and clinical evidence. J Child Neurol 1998;13:501-9.. PubMed
Sandyk R, Tsagas N, Anninos PA. Melatonin as a proconvulsive hormone in humans. Int J Neurosci 1992;63:125-35.. PubMed
Golombek DA, Escolar E, Burin LJ, et al. Chronopharmacology of melatonin: inhibition by benzodiazepine antagonism. Chronobiol Int 1992;9:124-31.. PubMed
Smits MG, Nagtegaal EE, van der Heijden J, et al. Melatonin for chronic sleep onset insomnia in children: a randomized placebo-controlled trial. J Child Neurol 2001;16:86-92.. PubMed
Cagnacci A, Arangino S, Renzi A, et al. Influence of melatonin administration on glucose tolerance and insulin sensitivity of postmenopausal women. Clin Endocrinol (Oxf) 2001;54:339-46.. PubMed
Williamson BL, Tomlinson AJ, Naylor S, Gleich GJ. Contaminants in commercial preparations of melatonin. Mayo Clin Proc 1997;72:1094-5. PubMed
Williamson BL, Tomlinson AJ, Mishra PK, et al. Structural characterization of contaminants found in commercial preparations of melatonin: similarities to case-related compounds from L-tryptophan associated with eosinophilia-myalgia syndrome. Chem Res To
Stewart LS. Endogenous melatonin and epileptogenesis: facts and hypothesis. Int J Neurosci 2001;107:77-85.. PubMed
Molina-Carballo A, Munoz-Hoyos A, Reiter RJ, et al. Utility of high doses of melatonin as adjunctive anticonvulsant therapy in a child with severe myoclonic epilepsy: two years' experience. J Pineal Res 1997;23:97-105.. PubMed
Tjon Pian Gi CV, Broeren JP, Starreveld JS, A Versteegh FG. Melatonin for treatment of sleeping disorders in children with attention deficit/hyperactivity disorder: a preliminary open label study. Eur J Pediatr 2003;162:554-5. PubMed
Secreto G, Chiechi LM, Amadori A, et al. Soy isoflavones and melatonin for the relief of climacteric symptoms: a multicenter, double-blind, randomized study. Maturitas 2004;47:11-20. PubMed
Weiss MD, Wasdell MB, Bomben MM, et al. Sleep hygiene and melatonin treatment for children and adolescents with ADHD and initial insomnia. J Am Acad Child Adolesc Psychiatry 2006;45:512-9. DOI
Saha L, Malhotra S, Rana S, et al. A preliminary study of melatonin in irritable bowel syndrome. J Clin Gastroenterol 2007;41:29-32. PubMed
Hussain, SA, Khadim, HM, Khalaf, BH, et al. Effects of melatonin and zinc on glycemic control in type 2 diabetic patients poorly controlled with metformin. Saudi Med J 2006;27:1483-8. DOI
Kadhim, HM, Ismail, SH, Hussein, KI, et al. Effects of melatonin and zinc on lipid profile and renal function in type 2 diabetic patients poorly controlled with metformin. J Pineal Res 2006;41:189-93. PubMed
Mutluay R. Elbeg S. Karakus R. et al. The Impact of Melatonin on Glucose Homeostasis. Turkish Journal of Endocrinology and Metabolism 2009;13:52-55.
Wright KP Jr, Badia P, Myers BL, et al. Caffeine and light effects on nighttime melatonin and temperature levels in sleep-deprived humans. Brain Res. 1997;747(1):78-84. PubMed
Peuhkuri K, Sihvola N, Korpela R. Dietary factors and fluctuating levels of melatonin. Food Nutr Res. 2012;56. doi: 10.3402/fnr.v56i0.17252. Epub 2012 Jul 20. PubMed
Gibb JW, Bush L, Hanson GR. Exacerbation of methamphetamine-induced neurochemical deficits by melatonin. J Pharmacol Exp Ther. 1997;283(2):630-5. DOI
Sunami E, Usuda K, Nishiyama Y, et al. A preliminary study of fluvoxamine maleate on depressive state and serum melatonin levels in patients after cerebral infarction. Intern Med. 2012;51(10):1187-93. PubMed
Babkoff, H., French, J., Whitmore, J., and Sutherlin, R. Single-dose bright light and/or caffeine effect on nocturnal performance. Aviat.Space Environ.Med. 2002;73(4):341-350.
Rossignol, D. A. Novel and emerging treatments for autism spectrum disorders: a systematic review. Ann.Clin Psychiatry 2009;21(4):213-236. DOI
Yeleswaram, K., Vachharajani, N., and Santone, K. Involvement of cytochrome P-450 isozymes in melatonin metabolism and clinical implications. J Pineal Res 1999;26(3):190-191. PubMed
Jan, J. E., Connolly, M. B., Hamilton, D., Freeman, R. D., and Laudon, M. Melatonin treatment of non-epileptic myoclonus in children. Dev.Med Child Neurol. 1999;41(4):255-259. PubMed
Edwards, B. J., Atkinson, G., Waterhouse, J., Reilly, T., Godfrey, R., and Budgett, R. Use of melatonin in recovery from jet-lag following an eastward flight across 10 time-zones. Ergonomics 2000;43(10):1501-1513. PubMed
Cagnacci, A., Arangino, S., Angiolucci, M., Melis, G. B., Facchinetti, F., Malmusi, S., and Volpe, A. Effect of exogenous melatonin on vascular reactivity and nitric oxide in postmenopausal women: role of hormone replacement therapy. Clin Endocrinol (Oxf PubMed
Wakatsuki, A., Okatani, Y., Ikenoue, N., Kaneda, C., and Fukaya, T. Effects of short-term melatonin administration on lipoprotein metabolism in normolipidemic postmenopausal women. Maturitas 4-20-2001;38(2):171-177. PubMed
Kitajima, T., Kanbayashi, T., Saitoh, Y., Ogawa, Y., Sugiyama, T., Kaneko, Y., Sasaki, Y., Aizawa, R., and Shimisu, T. The effects of oral melatonin on the autonomic function in healthy subjects. Psychiatry Clin Neurosci. 2001;55(3):299-300. PubMed
Calvo, J. R., Guerrero, J. M., Osuna, C., Molinero, P., and Carrillo-Vico, A. Melatonin triggers Crohn's disease symptoms. J Pineal Res 2002;32(4):277-278. PubMed
Luboshitzky, R., Shen-Orr, Z., Nave, R., Lavi, S., and Lavie, P. Melatonin administration alters semen quality in healthy men. J Androl 2002;23(4):572-578. DOI
Rufo-Campos, M. [Melatonin and epilepsy]. Rev Neurol. 2002;35 Suppl 1:S51-S58.
Ursing, C., Wikner, J., Brismar, K., and Rojdmark, S. Caffeine raises the serum melatonin level in healthy subjects: an indication of melatonin metabolism by cytochrome P450(CYP)1A2. J.Endocrinol.Invest 2003;26(5):403-406. PubMed
Smits, M. G., van Stel, H. F., van der, Heijden K., Meijer, A. M., Coenen, A. M., and Kerkhof, G. A. Melatonin improves health status and sleep in children with idiopathic chronic sleep-onset insomnia: a randomized placebo-controlled trial. J Am Acad.Chi PubMed
Boeve, B. F., Silber, M. H., and Ferman, T. J. Melatonin for treatment of REM sleep behavior disorder in neurologic disorders: results in 14 patients. Sleep Med. 2003;4(4):281-284. PubMed
Hartter, S., Nordmark, A., Rose, D. M., Bertilsson, L., Tybring, G., and Laine, K. Effects of caffeine intake on the pharmacokinetics of melatonin, a probe drug for CYP1A2 activity. Br.J.Clin.Pharmacol. 2003;56(6):679-682. PubMed
Scheer, F. A., Van Montfrans, G. A., van Someren, E. J., Mairuhu, G., and Buijs, R. M. Daily nighttime melatonin reduces blood pressure in male patients with essential hypertension. Hypertension 2004;43(2):192-197. PubMed
Buscemi, N., Vandermeer, B., Pandya, R., Hooton, N., Tjosvold, L., Hartling, L., Baker, G., Vohra, S., and Klassen, T. Melatonin for treatment of sleep disorders. Evid.Rep.Technol.Assess.(Summ.) 2004;(108):1-7.
Cavallo, A., Ris, M. D., Succop, P., and Jaskiewicz, J. Melatonin treatment of pediatric residents for adaptation to night shift work. Ambul.Pediatr. 2005;5(3):172-177. PubMed
Faber, M. S., Jetter, A., and Fuhr, U. Assessment of CYP1A2 activity in clinical practice: why, how, and when? Basic Clin Pharmacol Toxicol. 2005;97(3):125-134. PubMed
Cagnacci, A., Cannoletta, M., Renzi, A., Baldassari, F., Arangino, S., and Volpe, A. Prolonged melatonin administration decreases nocturnal blood pressure in women. Am J Hypertens. 2005;18(12 Pt 1):1614-1618. PubMed
Weekley, L. B. Melatonin-induced relaxation of rat aorta: interaction with adrenergic agonists. J Pineal Res 1991;11(1):28-34. PubMed
Grossman, E., Laudon, M., Yalcin, R., Zengil, H., Peleg, E., Sharabi, Y., Kamari, Y., Shen-Orr, Z., and Zisapel, N. Melatonin reduces night blood pressure in patients with nocturnal hypertension. Am J Med 2006;119(10):898-902. PubMed
van der Heijden, K. B., Smits, M. G., van Someren, E. J., Ridderinkhof, K. R., and Gunning, W. B. Effect of melatonin on sleep, behavior, and cognition in ADHD and chronic sleep-onset insomnia. J Am Acad.Child Adolesc.Psychiatry 2007;46(2):233-241. PubMed
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Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Melatonin and Gemcitabine Together: Common Questions

Is it safe to take Melatonin with Gemcitabine?

We do not list a known interaction between Melatonin and Gemcitabine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

Do Melatonin and Gemcitabine have any of the same side effects?

Yes — our sources link each of them separately to 3 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.

How was the Melatonin and Gemcitabine combination checked?

Interactions in our licensed database are recorded against drug classes. Gemcitabine is filed under 2 classifications, and Melatonin has documented interactions with 18 drug classes — none of Gemcitabine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.

Does Melatonin interact with any other medications?

Yes. Melatonin has 1,461 documented drug interactions in our database — Gemcitabine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Does Gemcitabine interact with any supplements?

Yes. Gemcitabine has documented interactions with 39 supplements in our database — Melatonin is not one of them. The Gemcitabine interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.