Comparison
Oxytocin vs. Bremelanotide
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Research other
Research other
CAS no.
50-56-6
189691-06-3
Molecular weight
1007.19 g/mol
1025.18 g/mol
Half-life
0.05 h
2.7 h
Sequence
Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-OHMechanism of action
Oxytocin
Oxytocin is synthesised in the hypothalamus and released via the posterior pituitary. Peripherally it binds the oxytocin receptor, a G-protein-coupled receptor, and through the phospholipase-C cascade and calcium release triggers contraction of uterine smooth muscle and milk ejection — the pharmacological basis of the obstetric approval. Centrally, oxytocin acts as a neuromodulator and has been linked to social bonding, trust and modulation of stress and anxiety circuits. Its central effects in humans are mechanistically incompletely understood, particularly because it is unclear to what extent peripherally or intranasally administered oxytocin crosses the blood-brain barrier.
Bremelanotide
Bremelanotide is a cyclic peptide that binds non-selectively to melanocortin receptors (MC1R through MC5R) — with highest affinity at MC4R in the central nervous system. The precise role of MC4R activation in sexual behaviour is not fully understood; animal data show effects on hypothalamic circuits. Peripheral effects (blood pressure, hyperpigmentation) are attributed to MC1R/MC2R.
Evidence base
Highest evidence
Human RCT
Human RCT
Studies
4
5
of which in humans
4
5
Effects recorded
3
3
Open conflicts
1
1
Documented adverse events
0
2
Legal status
Full entries
Frequently asked questions
- What is the difference between Oxytocin and Bremelanotide?
- Oxytocin is classified as "Research other", while Bremelanotide is classified as "Research other". Oxytocin: Oxytocin is an endogenous nonapeptide hormone of the posterior pituitary. In synthetic form (Pitocin, Syntocinon) it has been approved for decades to induce and augment labour and to control postpartum uterine bleeding. Strictly separate from this is intranasal use to influence social behaviour, trust, anxiety or autism symptoms: this use is unapproved, purely experimental, and yields inconsistent and often negative results in controlled trials. Bremelanotide: Synthetic cyclic heptapeptide acting as a non-selective melanocortin-receptor agonist. FDA-approved in 2019 as Vyleesi for hypoactive sexual desire disorder (HSDD) in pre-menopausal women. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
- Which peptide is better supported by science, Oxytocin or Bremelanotide?
- The highest available evidence level is "Human RCT" for Oxytocin and "Human RCT" for Bremelanotide. 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 Oxytocin and Bremelanotide in Germany and the United States?
- Germany: Oxytocin — Prescription, Bremelanotide — Unapproved. United States: Oxytocin — Prescription, Bremelanotide — Prescription. These are factual summaries with source and review date on the individual pages.