Comparison
Gonadorelin vs. Melanotan II
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Research other
Research other
CAS no.
33515-09-2
121062-08-6
Molecular weight
1182.29 g/mol
1024.18 g/mol
Half-life
0.1 h
1 h
Sequence
pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2Mechanism of action
Gonadorelin
Gonadorelin acts as an agonist at the GnRH receptor on the gonadotroph cells of the pituitary and triggers release of the gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The temporal pattern of receptor exposure is decisive: pulsatile administration mimics the natural hypothalamic secretory rhythm and sustains LH/FSH release, whereas continuous exposure leads to receptor internalisation and desensitisation with subsequent paradoxical suppression of gonadotropins. The latter principle is exploited therapeutically by longer-acting GnRH agonists.
Melanotan II
Melanotan II binds non-selectively to all five melanocortin-receptor subtypes (MC1R-MC5R). Via MC1R in melanocytes, eumelanin synthesis is stimulated (pigmenting effect). Via MC4R and MC3R in the CNS, appetite, sexual function and blood pressure are modulated. The cyclic structure and D-amino acids increase stability compared to natural α-MSH.
Evidence base
Highest evidence
Human trial
Human trial
Studies
4
9
of which in humans
4
5
Effects recorded
4
4
Open conflicts
1
1
Documented adverse events
2
6
Legal status
Full entries
Frequently asked questions
- What is the difference between Gonadorelin and Melanotan II?
- Gonadorelin is classified as "Research other", while Melanotan II is classified as "Research other". Gonadorelin: Gonadorelin is the synthetic decapeptide with an amino-acid sequence identical to endogenous gonadotropin-releasing hormone (GnRH/LHRH). Historically approved in several countries for diagnostic testing of pituitary function and for fertility indications (pump systems). A defining feature is the opposite effect of pulsatile versus continuous administration: pulsatile stimulates, continuous leads to receptor desensitisation. Melanotan II: Cyclic hepta-peptide and non-selective melanocortin-receptor agonist. Originally researched at the University of Arizona as a sun-protection concept — never approved as a medicine. Widespread on the black market; regulatory warnings for cardiovascular and oncological risks. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
- Which peptide is better supported by science, Gonadorelin or Melanotan II?
- The highest available evidence level is "Human trial" for Gonadorelin and "Human trial" for Melanotan II. A higher evidence level means more robust data, but says nothing about suitability for an individual. The full body of evidence is on each peptide's own page.
- What is the legal status of Gonadorelin and Melanotan II in Germany and the United States?
- Germany: Gonadorelin — Prescription, Melanotan II — Unapproved. United States: Gonadorelin — Prescription, Melanotan II — Unapproved. These are factual summaries with source and review date on the individual pages.