Comparison
Melanotan II vs. Semax
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Research other
Research other
CAS no.
121062-08-6
80714-61-0
Molecular weight
1024.18 g/mol
813.92 g/mol
Half-life
1 h
0.3 h
Sequence
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2Met-Glu-His-Phe-Pro-Gly-ProMechanism of action
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.
Semax
Semax is a tetracosactide fragment analog without hormonal activity at MC2R. Proposed mechanisms include elevation of BDNF and NGF in hippocampus and striatum (in animal models), modulation of dopamine metabolism, and neuroprotective effects via anti-apoptotic pathways. A clear primary receptor is not established.
Evidence base
Highest evidence
Human trial
Human trial
Studies
5
4
of which in humans
5
2
Effects recorded
4
3
Open conflicts
0
0
Documented adverse events
3
1