PT-141 / Oxytocin
Melanocortin agonist paired with oxytocin, studied for arousal
In short
- PT-141 (bremelanotide) plus oxytocin, used for sexual and social effects.
- NEITHER is a growth hormone compound. The library description previously said otherwise; that was wrong and has been corrected.
- PT-141 is FDA-approved as Vyleesi for hypoactive sexual desire disorder in premenopausal women — but as a single-use autoinjector at a fixed 1.75 mg dose.
- Both components can cause nausea, and combining them stacks the most common adverse effect of each.
- PT-141 transiently raises blood pressure, which is why its label limits use to one dose per 24 hours and eight per month.
Structure
A blend of two peptides. See the PT-141 and Oxytocin entries for their individual structures.
How it works
PT-141 is a cyclic heptapeptide agonist at melanocortin receptors, principally MC4R and MC1R. MC4R signalling in the hypothalamus is involved in sexual desire and arousal — a central mechanism, unlike the peripheral vascular action of PDE5 inhibitors.
Oxytocin acts on oxytocin receptors in the amygdala, nucleus accumbens, and hypothalamus, implicated in social bonding and, peripherally, in smooth muscle contraction.
The pairing rationale is that one addresses desire and the other connection. They act on entirely separate receptor systems, so this is additive rather than synergistic, and no study has evaluated the combination.
What the research shows
PT-141 has genuine phase 3 evidence (RECONNECT) in premenopausal women with HSDD, with modest effect sizes that have been debated in the literature.
Oxytocin's social-cognition literature has replicated poorly, and how much intranasal oxytocin reaches the brain remains disputed. Its approved use is obstetric and injectable.
The combination has never been studied.
Dosing in the literature
Figures below are quoted from published studies, with the species or population they were measured in. They are records of what was studied, not recommendations.
| Studied in | Amount | Route | Source |
|---|---|---|---|
| Human — PT-141 approved label (Vyleesi), premenopausal women with HSDD | 1.75 mg as needed; maximum one dose per 24 hours and eight per month | subcutaneous autoinjector | FDA label |
| Human — intranasal oxytocin social cognition studies | Commonly 24 IU as a single dose | intranasal | PubMed |
Commonly reported ranges
These are amounts people report using. They are not from any study, have not been evaluated for safety, and are reproduced here only because they circulate widely and are better seen alongside the evidence than instead of it.
| Reported by | Amount | Route |
|---|---|---|
| Commonly reported combined use | Roughly 0.5–1.5 mg PT-141 with 100–400 µg oxytocin, as needed | subcutaneous |
No study has tested this specific combination in humans. Whatever evidence exists belongs to the individual components, tested individually. A pre-mixed vial fixes the ratio between components at whatever the vendor chose. You can change the total volume you draw, but you cannot change the proportions — so if one component suits you at a different relative amount, a blend cannot express that. Buying components separately costs more vials and buys back that control. The PT-141 label limits — one dose per 24 hours, eight per month — exist because of a documented cardiovascular effect and were part of the approved safety profile. A blend does not change that, and the limits apply to the PT-141 content regardless of what it is mixed with. Note also that oxytocin's studied route is intranasal, not injected.
Handling and storage
Supplied as a lyophilised powder requiring reconstitution with bacteriostatic water. The powder is comparatively stable; once reconstituted it is refrigerated and used within weeks. Track the date you reconstitute each vial — the Inventory section does this, and it is the difference between knowing a vial is three weeks old and guessing.
Subcutaneous injection is the community route, typically 45 minutes or more before anticipated activity, following PT-141's label timing.
Oxytocin is unstable and requires refrigeration; degradation in an unregulated preparation is a genuine practical issue.
Side effects
Nausea is the dominant effect and the main reason this combination is worth thinking about carefully — PT-141 caused nausea in roughly 40% of trial participants, and oxytocin can contribute. Combining two nausea sources is the clearest interaction here.
PT-141 produces transient increases in blood pressure and decreases in heart rate after each dose, which is why it is contraindicated in uncontrolled hypertension and known cardiovascular disease.
Focal hyperpigmentation can occur with repeated PT-141 use, reflecting MC1R activity.
Oxytocin retains some antidiuretic activity, so high or repeated dosing with large fluid intake carries a hyponatraemia consideration.
Combinations
Running components together makes attribution impossible in both directions. If something improves you cannot tell which component did it, and if something goes wrong you cannot tell which one to stop. Blends are convenient and they are also the format that teaches you least about your own response.
The specific caution for this pair is compounding nausea, and PT-141's blood pressure effect, which does not become safer by dilution into a blend.
Research status
PT-141 has a real phase 3 programme and an approval. Oxytocin has decades of obstetric use and a troubled social-neuroscience literature.
The combination has no research.
Legal status
PT-141 is FDA-approved and prescription-only for a specific indication in premenopausal women. Injectable oxytocin is approved for obstetric use. Research-market versions of either, and any blend of them, are unapproved.
WADA status
Neither component is currently named on the WADA Prohibited List. Verify against the live list before competition.
Conclusion
This blend pairs an approved medicine used outside its indication with a hormone whose behavioural literature has largely failed to replicate.
The practical point is the one from PT-141's label: the dosing frequency limits exist for a cardiovascular reason, and mixing it with something else does not suspend them.
Sources
Track your own PT-141 / Oxytocin protocol
Peppers logs your doses, models your levels from this half-life, tracks your vials and tells you when you will run out. Free on iPhone.
Reference and educational information only. Not medical advice. Nothing here diagnoses, treats, or prescribes, and nothing here is a recommendation to use any compound. The compounds described are research chemicals and are not approved for human consumption. Legal and anti-doping status change — the review date above is when these claims were last checked. Talk to a qualified clinician about anything you intend to take.