Melatonin 2mg modified-release capsules
Requires a prescription from a doctor or prescriber
Melatonin is a biogenic amine that is found in animals, plants and microbes.
Safety information for pregnancy and breastfeeding
Pregnancy
Breastfeeding
Oral, rat: LD50 ≥3200 mg/kg
Always consult your doctor or midwife before taking any medicine during pregnancy or while breastfeeding. Source: DrugBank (CC BY-NC 4.0).
Official documents, adverse reaction reporting, and safety monitoring
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Official medicine documents
Safety monitoring data
Yellow Card reports
The MHRA Yellow Card scheme collects reports of suspected side effects from healthcare professionals and patients. View the Drug Analysis Profile (iDAP) for real-world adverse reaction data.
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Suspected adverse reactions reported for Melatonin
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Submit a Yellow Card report to the MHRA
Data from the MHRA Yellow Card scheme. A reported reaction does not necessarily mean the medicine caused it. Contains public sector information licensed under the Open Government Licence v3.0.
EudraVigilance
The European Medicines Agency (EMA) collects suspected adverse reaction reports from across the EU/EEA through the EudraVigilance system. Search for safety data on this medicine.
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Suspected adverse reactions reported for Melatonin
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EudraVigilance data is published by the European Medicines Agency (EMA). A suspected adverse reaction is not necessarily caused by the medicine.
1 branded products available
WHO defined daily dose (DDD)
2 mg
Not a recommended dose. The DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults. It is a statistical measure used for research and comparison purposes only.
Source: WHO Collaborating Centre for Drug Statistics Methodology, distributed via NHS dm+d BNF mapping files. Contains public sector information licensed under the Open Government Licence v3.0.
Therapeutically similar medicines
Similarity based on WHO Anatomical Therapeutic Chemical (ATC) classification and NHS BNF section grouping. Source data: NHS dm+d via TRUD (OGL v3.0), WHO ATC/DDD Index.
NHS prescribing volume and spending trends
Clinical guidelines and formulary information
British National Formulary
Melatonin
Source: British National Formulary, NICE. Joint Formulary Committee. Contains public sector information licensed under the Open Government Licence v3.0.
NICE clinical guidance(7)
Melatonin for treating sleep disorders in adults who are blind (ES38)
Autism spectrum disorder in under 19s: support and management (CG170)
Parkinson's disease in adults (NG71)
Challenging behaviour and learning disabilities: prevention and interventions for people with learning disabilities whose behaviour challenges (NG11)
Cerebral palsy in under 25s: assessment and management (NG62)
Daridorexant for treating long-term insomnia (TA922)
Dementia: assessment, management and support for people living with dementia and their carers (NG97)
Source: National Institute for Health and Care Excellence (NICE). Contains public sector information licensed under the Open Government Licence v3.0.
Check stock at pharmacies and supply information
Pharmacy stock checkers
Search for this medicine at major UK pharmacy chains. These links open the retailer's own website — results depend on their current online catalogue.
Supply & product information
Official product databases and supply status monitoring
Pharmacy links redirect to the retailer's own search and do not represent real-time stock levels. emc (electronic medicines compendium) is operated by Datapharm Ltd. Shortage information sourced from NHS Specialist Pharmacy Service (SPS), sps.nhs.uk.
Codes for healthcare professionals and prescribing systems
These codes are used by healthcare IT systems and prescribers to identify this medicine.
NHS UK identifiers
Browse tools
SNOMED CT and dm+d codes from NHS TRUD (Technology Reference data Update Distribution), licensed under the Open Government Licence v3.0. BNF codes from NHS Business Services Authority (NHSBSA). ATC codes from the WHO Collaborating Centre for Drug Statistics Methodology (whocc.no).
Active and completed clinical studies from ClinicalTrials.gov
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine (NLM), National Institutes of Health (NIH). Data accessed via ClinicalTrials.gov API v2. Trial information is provided for research purposes and does not constitute medical advice.
Pharmacology and chemical data from DrugBank
Key facts
Drug status
Approved
Major interactions
1 found
Half-life
35 to 50 minutes
Mechanism
Melatonin is a derivative of tryptophan.
Food interactions
2 warnings
Human targets
9 targets
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
Half-life
35 to 50 minutes
Protein binding
Metabolism
65-88%
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
A number of studies have shown that melatonin may be effective for treating sleep-wake cycle disturbances in children and adolescents with mental retardation, autism, and other central nervous system disorders. It appears to decrease the time to fall asleep in children with developmental disabilities, such as cerebral palsy, autism, and mental retardation. It may also improve secondary insomnia associated with various sleep-wake cycle disturbances.
Other possible uses for which there is some evidence for include: benzodiazepine withdrawal, cluster headache, delayed sleep phase syndrome (DSPS), primary insomnia, jet lag, nicotine withdrawal, preoperative anxiety and sedation, prostate cancer, solid tumors (when combined with IL-2 therapy in certain cancers), sunburn prevention (topical use), tardive dyskinesia, thrombocytopenia associated with cancer, chemotherapy and other disorders.
Known interactions with other medications. Always consult a healthcare professional.
Showing 50 of 1022 interactions
Generally well-tolerated when taken orally. The most common side effects, day-time drowsiness, headache and dizziness, appear to occur at the same frequency as with placebo. Other reported side effects include transient depressive symptoms, mild tremor, mild anxiety, abdominal cramps, irritability, reduced alertness, confusion, nausea, vomiting, and hypotension.
Safety in Adults: Evidence indicates that it is likely safe to use in oral and parenteral forms for up to two months when used appropriately. Some evidence indicates that it can be safely used orally for up to 9 months in some patients. It is also likely safe to use topically when used appropriately.
Safety in Children: Melatonin appeared to be used safely in small numbers of children enrolled in short-term clinical trials. However, concerns regarding safety in children have arisen based on their developmental state. Compared to adults over 20 years of age, people under 20 produce high levels of melatonin.
Melatonin levels are inversely related to gonadal development and it is thought that exogenous administration of melatonin may adversely affect gonadal development. Safety during Pregnancy: High doses of melatonin administered orally or parenterally may inhibit ovulation. Not advised for use in individuals who are pregnant or trying to become pregnant.
Safety during Lactation: Not recommended as safety has not be established.
Oral, rat: LD50 ≥3200 mg/kg
MT1 receptors are expressed in many regions of the central nervous system (CNS): suprachiasmatic nucleus of the hypothalamus (SNC), hippocampus, substantia nigra, cerebellum, central dopaminergic pathways, ventral tegmental area and nucleus accumbens. MT1 is also expressed in the retina, ovary, testis, mammary gland, coronary circulation and aorta, gallbladder, liver, kidney, skin and the immune system. MT2 receptors are expressed mainly in the CNS, also in the lung, cardiac, coronary and aortic tissue, myometrium and granulosa cells, immune cells, duodenum and adipocytes.
The binding of melatonin to melatonin receptors activates a few signaling pathways. MT1 receptor activation inhibits the adenylyl cyclase and its inhibition causes a rippling effect of non activation; starting with decreasing formation of cyclic adenosine monophosphate (cAMP), and then progressing to less protein kinase A (PKA) activity, which in turn hinders the phosphorilation of cAMP responsive element-binding protein (CREB binding protein) into P-CREB. MT1 receptors also activate phospholipase C (PLC), affect ion channels and regulate ion flux inside the cell. The binding of melatonin to MT2 receptors inhibits adenylyl cyclase which decreases the formation of cAMP.[4] As well it hinders guanylyl cyclase and therefore the forming of cyclic guanosine monophosphate (cGMP). Binding to MT2 receptors probably affects PLC which increases protein kinase C (PKC) activity. Activation of the receptor can lead to ion flux inside the cell.
MT1 and MT2 receptors may be a target for the treatment of circadian and non circadian sleep disorders because of their differences in pharmacology and function within the SCN. SCN is responsible for maintaining the 24 hour cycle which regulates many different body functions ranging from sleep to immune functions
How the body processes this drug — absorption, distribution, metabolism, and elimination
Proteins and enzymes this drug interacts with in the body
Possibly involved in sleep induction, by melatonin activation of the potassium channel KCNMA1/BK and the dissociation of G-beta and G-gamma subunits, thereby decreasing synaptic transmission (By similarity)
Ligand binding induces a conformational change allowing subsequent or combinatorial association with multiprotein coactivator complexes through LXXLL motifs of their respective components. Mutual transrepression occurs between the estrogen receptor (ER) and NF-kappa-B in a cell-type specific manner. Decreases NF-kappa-B DNA-binding activity and inhibits NF-kappa-B-mediated transcription from the IL6 promoter and displace RELA/p65 and associated coregulators from the promoter.
Recruited to the NF-kappa-B response element of the CCL2 and IL8 promoters and can displace CREBBP. Present with NF-kappa-B components RELA/p65 and NFKB1/p50 on ERE sequences. Can also act synergistically with NF-kappa-B to activate transcription involving respective recruitment adjacent response elements; the function involves CREBBP.
Can activate the transcriptional activity of TFF1. Also mediates membrane-initiated estrogen signaling involving various kinase cascades. Essential for MTA1-mediated transcriptional regulation of BRCA1 and BCAS3 .
PMID:17922032
Maintains neuronal survival in response to ischemic reperfusion injury when in the presence of circulating estradiol (17-beta-estradiol/E2) (By similarity)
Modulates rod photoreceptors differentiation at least by inducing the transcription factor NRL-mediated pathway. In cone photoreceptor cells, regulates transcription of OPN1SW. Involved in the regulation of the period length and stability of the circadian rhythm.
May control cytoarchitectural patterning of neocortical neurons during development. May act in a dose-dependent manner to regulate barrel formation upon innervation of layer IV neurons by thalamocortical axons. May play a role in the suppression of osteoblastic differentiation through the inhibition of RUNX2 transcriptional activity (By similarity)
Enzymes involved in drug metabolism — important for understanding drug interactions
Proteins that transport this drug across cell membranes
PMID:14586168 PMID:15644426 PMID:15846473 PMID:16455804 PMID:31553721
Transports organic anions such as estrone 3-sulfate (E1S) and urate in exchange for dicarboxylates such as glutarate or ketoglutarate (2-oxoglutarate) .
PMID:14586168 PMID:15846473 PMID:15864504 PMID:22108572 PMID:23832370
Plays an important role in the excretion of endogenous and exogenous organic anions, especially from the kidney and the brain .
PMID:11306713 PMID:14586168 PMID:15846473
E1S transport is pH- and chloride-dependent and may also involve E1S/cGMP exchange .
PMID:26377792
Responsible for the transport of prostaglandin E2 (PGE2) and prostaglandin F2(alpha) (PGF2(alpha)) in the basolateral side of the renal tubule .
PMID:11907186
Involved in the transport of neuroactive tryptophan metabolites kynurenate and xanthurenate .
PMID:22108572 PMID:23832370
Functions as a biopterin transporters involved in the uptake and the secretion of coenzymes tetrahydrobiopterin (BH4), dihydrobiopterin (BH2) and sepiapterin to urine, thereby determining baseline levels of blood biopterins .
PMID:28534121
May be involved in the basolateral transport of steviol, a metabolite of the popular sugar substitute stevioside .
PMID:15644426
May participate in the detoxification/ renal excretion of drugs and xenobiotics, such as the histamine H(2)-receptor antagonists fexofenadine and cimetidine, the antibiotic benzylpenicillin (PCG), the anionic herbicide 2,4-dichloro-phenoxyacetate (2,4-D), the diagnostic agent p-aminohippurate (PAH), the antiviral acyclovir (ACV), and the mycotoxin ochratoxin (OTA), by transporting these exogenous organic anions across the cell membrane in exchange for dicarboxylates such as 2-oxoglutarate .
PMID:11669456 PMID:15846473 PMID:16455804
Contributes to the renal uptake of potent uremic toxins (indoxyl sulfate (IS), indole acetate (IA), hippurate/N-benzoylglycine (HA) and 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF)), pravastatin, PCG, E1S and dehydroepiandrosterone sulfate (DHEAS), and is partly involved in the renal uptake of temocaprilat (an angiotensin-converting enzyme (ACE) inhibitor) .
PMID:14675047
May contribute to the release of cortisol in the adrenals .
PMID:15864504
Involved in one of the detoxification systems on the choroid plexus (CP), removes substrates such as E1S or taurocholate (TC), PCG, 2,4-D and PAH, from the cerebrospinal fluid (CSF) to the blood for eventual excretion in urine and bile (By similarity). Also contributes to the uptake of several other organic compounds such as the prostanoids prostaglandin E(2) and prostaglandin F(2-alpha), L-carnitine, and the therapeutic drugs allopurinol, 6-mercaptopurine (6-MP) and 5-fluorouracil (5-FU) (By similarity). Mediates the transport of PAH, PCG, and the statins pravastatin and pitavastatin, from the cerebrum into the blood circulation across the blood-brain barrier (BBB).
In summary, plays a role in the efflux of drugs and xenobiotics, helping reduce their undesired toxicological effects on the body (By similarity)
Involved compounds
ATC N05CH01
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
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Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Linked compound data from DrugBank Open Data (CC BY-NC 4.0)
Melatonin
Additional database identifiers
Drugs Product Database (DPD)
7341
ChemSpider
872
BindingDB
9019
PDB
ML1
Guide to Pharmacology
1357
ZINC
ZINC000000057060
HUGO Gene Nomenclature Committee (HGNC)
HGNC:7463
GenAtlas
MTNR1A
GeneCards
MTNR1A
GenBank Gene Database
U14108
GenBank Protein Database
602130
Guide to Pharmacology
287
UniProt Accession
MTR1A_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:7464
GenAtlas
MTNR1B
GeneCards
MTNR1B
GenBank Gene Database
U25341
GenBank Protein Database
971194
Guide to Pharmacology
288
UniProt Accession
MTR1B_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:7856
GenAtlas
NQO2
GeneCards
NQO2
GenBank Gene Database
J02888
GenBank Protein Database
190818
UniProt Accession
NQO2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:3467
GenAtlas
ESR1
GeneCards
ESR1
GenBank Gene Database
X03635
GenBank Protein Database
31234
Guide to Pharmacology
620
UniProt Accession
ESR1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:10259
GeneCards
RORB
GenBank Gene Database
Y08639
GenBank Protein Database
1619294
Guide to Pharmacology
599
UniProt Accession
RORB_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:7218
GenAtlas
MPO
GeneCards
MPO
GenBank Gene Database
J02694
GenBank Protein Database
189040
Guide to Pharmacology
2789
UniProt Accession
PERM_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:3423
GeneCards
EPX
GenBank Gene Database
X14346
GenBank Protein Database
31183
UniProt Accession
PERE_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:1455
GenAtlas
CALR
GeneCards
CALR
GenBank Gene Database
M32294
GenBank Protein Database
337487
UniProt Accession
CALR_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:1442
GeneCards
CALM1
UniProt Accession
CALM1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:1445
GeneCards
CALM2
UniProt Accession
CALM2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:1449
GeneCards
CALM3
UniProt Accession
CALM3_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2595
GeneCards
CYP1A1
GenBank Gene Database
K03191
GenBank Protein Database
181276
Guide to Pharmacology
1318
UniProt Accession
CP1A1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2596
GenAtlas
CYP1A2
GeneCards
CYP1A2
GenBank Gene Database
Z00036
Guide to Pharmacology
1319
UniProt Accession
CP1A2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2597
GenAtlas
CYP1B1
GeneCards
CYP1B1
GenBank Gene Database
U03688
GenBank Protein Database
501031
Guide to Pharmacology
1320
UniProt Accession
CP1B1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2621
GeneCards
CYP2C19
GenBank Gene Database
M61854
GenBank Protein Database
181344
Guide to Pharmacology
1328
UniProt Accession
CP2CJ_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2623
GenAtlas
CYP2C9
GeneCards
CYP2C9
GenBank Gene Database
AY341248
Guide to Pharmacology
1326
UniProt Accession
CP2C9_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:750
GeneCards
ASMT
GenBank Gene Database
U11090
GenBank Protein Database
607840
UniProt Accession
ASMT_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:6059
GenAtlas
INDO
GeneCards
IDO1
GenBank Gene Database
M34455
GenBank Protein Database
306956
Guide to Pharmacology
2829
UniProt Accession
I23O1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:7218
GenAtlas
MPO
GeneCards
MPO
GenBank Gene Database
J02694
GenBank Protein Database
189040
Guide to Pharmacology
2789
UniProt Accession
PERM_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2594
GenAtlas
CYP19A1
GeneCards
CYP19A1
GenBank Gene Database
M22246
GenBank Protein Database
179002
Guide to Pharmacology
1362
UniProt Accession
CP19A_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:10972
GeneCards
SLC22A8
GenBank Gene Database
AF097491
GenBank Protein Database
4378059
Guide to Pharmacology
1027
UniProt Accession
S22A8_HUMAN
International reference pricing
Reference pricing from DrugBank. Prices are indicative and may not reflect current UK costs.
Source: DrugBank. Used under CC BY-NC 4.0 academic licence for non-commercial purposes.
DrugBank citations
If you use DrugBank data in your research, please cite the following publications: