PT-141 with oxytocin
Bremelanotide (PT-141) with oxytocin acetate
Written by Aaron CuhaReviewed Sep 2026
Also known as: PT-141 oxytocin blend, Intimacy blend
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
A 15 mg vial, usually 10 mg PT-141 and 5 mg oxytocin. PT-141 is an approved drug with two big trials behind it. The oxytocin half was tested for this exact job and it lost to a dummy spray.
What people take it for
- More desire and arousal.
- Feeling closer to a partner.
- Help with sex problems that talking has not fixed.
What the trials actually showed
The mix has never been tested. PT-141 has two phase 3 trials in women with low sex drive, which is what it is approved for. Now the oxytocin. Thirty women with sexual problems used a nasal spray of oxytocin or a dummy spray before sex for eight weeks, then swapped. Sexual function scores went up 26 percent on oxytocin and 31 percent on the dummy. Quality of life scores went up 144 percent on oxytocin and 125 percent on the dummy. Distress went down 36 percent on oxytocin and 45 percent on the dummy. There was no real difference between them. Everybody got better. The drug did not beat the dummy on anything. One more thing. That study used a nose spray on purpose. Oxytocin shot into your blood barely reaches your brain. This vial is a shot. The math: mix 15 mg with 3 mL and every unit mark carries about 33 micrograms of PT-141 and 17 of oxytocin. The approved PT-141 dose of 1.75 mg is about 53 units, which also puts in about 0.88 mg of oxytocin.
What people report
Reports, not trial results
The good
- More desire and arousal within a few hours.
- A warm, close feeling that people credit to the oxytocin.
The bad
- Nausea and flushing. This is the most common report and it is a known effect of this drug family.
- Headache.
- Sore shot sites.
- People who have used PT-141 on its own often say they cannot tell the difference, which is what the oxytocin trial would predict.
Where these come from: The nausea and flushing come from controlled trials of this drug family. The rest comes from forums and clinic write-ups, in an area where the dummy arm of a real trial improved as much as the drug arm.
My bottom line
The PT-141 half is the real thing. The oxytocin half failed its own trial and is being given by the route least likely to work. You are paying for a third of a vial that does nothing.
An opinion, not a finding. I am a coach, not a doctor.
Overview
A 15 mg vial, commonly 10 mg bremelanotide with 5 mg oxytocin, so two thirds of the powder is the melanocortin and one third the hormone. Bremelanotide has two phase 3 trials behind its approval; the oxytocin half has a randomised crossover trial in 30 women where oxytocin and placebo both improved sexual function with no treatment effect. The combination has never been tested.
This vial is sold as a two-part answer to sexual difficulties: one component for desire and arousal, one for connection and bonding. The second half is where the page has to be blunt.
Bremelanotide is an approved medicine, studied in two randomised phase 3 trials in premenopausal women with hypoactive sexual desire disorder. That is a real regulatory file with real endpoints.
Oxytocin's file for sexual function is not. In a randomised, double-blind, placebo-controlled crossover trial, 30 pre- and postmenopausal women with sexual dysfunction self-administered 32 IU of intranasal oxytocin or placebo before intercourse over eight weeks, then crossed over. Female Sexual Function Index scores rose 26% on oxytocin and 31% on placebo. Sexual Quality of Life scores rose 144% on oxytocin and 125% on placebo. Sexual distress fell 36% on oxytocin and 45% on placebo. There was no statistically significant treatment, sequence or interaction effect. Both arms improved and the drug did not beat the placebo on anything.
That is the most important result on this page and it is easy to misread in the direction people want. Oxytocin did not fail to do anything: scores improved substantially in the people taking it. So did the scores of the people taking saline. In an area this responsive to expectation, an uncontrolled report of an oxytocin blend working is exactly what the placebo arm of that trial looked like.
The arithmetic on the common 10 plus 5 mg vial in a 3 mL vial: 15 mg of powder, bremelanotide 66.7% and oxytocin 33.3%. Reconstitute with 3 mL and you have 5 mg/mL total, 3.33 mg/mL of bremelanotide and 1.67 mg/mL of oxytocin. One unit on a 100 unit insulin syringe carries about 33 micrograms of bremelanotide and 17 micrograms of oxytocin. The approved bremelanotide dose is 1.75 mg, which from this vial is about 53 units, delivering about 0.88 mg of oxytocin at the same time. Nobody has established a subcutaneous oxytocin dose for this purpose, so that figure is an output of the vendor's ratio rather than a considered amount.
Mechanism of action
Bremelanotide is a melanocortin receptor agonist acting largely through melanocortin 4 receptor signalling in the central nervous system, which is the desire and arousal pathway. Oxytocin is a nine amino acid posterior pituitary hormone with well characterised roles in labour and lactation and a far less settled role in social and sexual behaviour. Injected oxytocin crosses into the brain poorly, which is why the research that exists mostly uses the intranasal route.
Human evidence
One half is an approved drug with two phase 3 trials. The other half has a randomised trial in which it did not beat placebo for this purpose. The combination has none.
- The blend: no published study, no registered trial.
- Bremelanotide: two randomised phase 3 trials in premenopausal women with hypoactive sexual desire disorder.
- Oxytocin for sexual dysfunction: 30 women, randomised crossover, no significant treatment effect. Scores improved 26% on oxytocin and 31% on placebo.
- Melanocortin class side effects, including nausea, appear in the controlled trials of this drug family.
What this does not tell you: The oxytocin trial used the intranasal route, which is how oxytocin brain research is done because injected oxytocin crosses into the brain poorly. This vial is injected. That makes the oxytocin half less likely to do what it is sold for here, not more.
What it has been measured to do
Measured in people
Goals PT-141 with oxytocin has been measured for in a human being, most people first. Counts come from the study lines on this page and deliberately undercount.
- Mood and anxietyno headcount stated · 1 study
- Libido and sexual functionno headcount stated · 1 study
What people using it report
Uncontrolled and self-selected, so it cannot show that anything works. It is still the best guide on this page to what people actually do with PT-141 with oxytocin, what they expect, and what goes wrong. The full account, including the negative reports, is below.
33 of the 36 indexed goals have no study of any kind behind PT-141 with oxytocin
No trial, no animal work, no cell work on this page reports a result for these. That is an absence of evidence rather than evidence of absence, but it does mean anything you have been told about PT-141 with oxytocin and one of these did not come from a study cited here.
Reading the research record
Two features of this area make uncontrolled reports almost useless, and the oxytocin trial demonstrates both. Sexual function measures move a long way on expectation, and they move a long way simply from being measured and discussed. The placebo arm in that trial improved its quality of life score by 125%.
The route problem deserves its own note. Almost all the human research suggesting oxytocin affects social and emotional behaviour uses intranasal delivery, because oxytocin injected into the bloodstream reaches the brain poorly. A subcutaneous blend takes the component whose claimed effect is central and gives it by the route least likely to get it there.
The last point is about the ratio. Bremelanotide has an approved dose. Oxytocin, for this purpose, does not, so the amount delivered is whatever falls out of the vendor's split when you draw the amount you actually wanted.
The evidence, charted
Fig. 1a · evidence scale
10people, across 1 human study cited here
- 1998 · Journal of Urology10100%
The whole total is one study of 10. Counts are the enrollment each human citation on this page states, which includes observational cohorts where nobody was given the compound. 2 further human citations state no participant count and are not counted here. Studies still recruiting are excluded, and only studies cited on this page are counted.
Fig. 1b · evidence mix
All 3 citations here are human work.
- Human · given to people3100%
Counted from the citation list on this page, typed as this page types it. It understates any literature larger than the sources we cite, and a review counts once however many studies it covers.
Fig. 2 · evidence over time
Evidence spans 3 distinct years, 1998 to 2019, counted from the citation list on this page. The newest citation on file is from 2019, more than five years ago; the published record may have gone quiet.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four jurisdictions shown. A jurisdiction's classification is a regulatory fact, not a verdict on the science; see Legal status below for the full text and any notes.
Fig. 4 · dose response
No human dose response curve exists
We draw this figure where the data supports it. For this compound in humans it does not, so the panel stays empty rather than borrowing an animal curve and implying it transfers.
Fig. 5 · molecular identity
- Modality
- Blend
- Molecular weight
- Not on file
- Half-life
- Stated in words, not a number
- Sequence length
- None on file
see the exact wording below
Half-life as stated on file: Not defined for the blend. Oxytocin disappears from plasma very quickly, the melanocortin component is used episodically, and the mixture has never been measured.
No amino acid sequence is on file for PT-141 with oxytocin, which is expected: a blend is not built from residues.
Fig. 6 · what is in the vial
66.7%of a 15 mg PT-141 with oxytocin vial is Bremelanotide (PT-141)
- Bremelanotide (PT-141)10 mg66.7%
- Oxytocin acetate5 mg33.3%
Label mass from a standard vial, not a dose, and not an assay. The ratio is fixed by the seller, so a draw that hits the amount you want of one component sets the amount of every other component with it. No study has tested this combination in any species.
Key studies & citations
- Human2019
Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials
Two randomised phase 3 trials of bremelanotide in premenopausal women with hypoactive sexual desire disorder, the studies on which its approval rests. Bremelanotide alone, with no oxytocin co-administered.
Obstetrics and Gynecology - Human2015
Effect of long-term intranasal oxytocin on sexual dysfunction in premenopausal and postmenopausal women: a randomized trial
Thirty pre- and postmenopausal women with sexual dysfunction, randomised double-blind placebo-controlled crossover over 22 weeks, 32 IU of intranasal oxytocin or placebo before intercourse. Female Sexual Function Index rose 26% on oxytocin and 31% on placebo, Sexual Quality of Life 144% and 125%, and sexual distress fell 36% and 45%. There was no statistically significant treatment, sequence or interaction effect. Both improved; the drug did not beat placebo.
Fertility and Sterility - Human1998
Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study
Ten men, double-blind placebo-controlled crossover with RigiScan monitoring. 8 of 10 developed clinically apparent erections on the melanocortin analogue, with mean tip rigidity above 80% lasting 38.0 minutes against 3.0 minutes on placebo. Nausea, yawning and stretching were more frequent on drug. The melanocortin class effect that also applies to bremelanotide.
Journal of Urology
What users report
Self-reported experiences, not evidence. Nothing below was measured under controlled conditions, and reports like these cannot separate a real effect from placebo, from the training or diet change that accompanied it, or from what the product actually contained. They are here because knowing what people describe, including what goes wrong, is worth reading alongside the studies.
- Nausea and flushing, the dominant report and a known melanocortin class effect.
- Increased desire and arousal within a few hours.
- A feeling of warmth or closeness that people credit to the oxytocin.
- Headache.
- Injection site irritation.
- No difference against bremelanotide alone, reported by people who have used both, which is what the oxytocin trial would predict.
Sources: The nausea and flushing appear in the melanocortin controlled trials. The rest comes from forums including r/peptides and clinic write-ups, uncontrolled, in an area where the placebo arm of a randomised trial improved as much as the drug arm.
Frequently asked questions
Does the oxytocin half work?
In the randomised trial that tested it for sexual dysfunction, no. Thirty women received intranasal oxytocin or placebo in a crossover design and there was no significant treatment effect. Scores improved 26% on oxytocin and 31% on placebo.
What do I get per unit?
On a 10 mg bremelanotide plus 5 mg oxytocin vial reconstituted with 3 mL, one unit carries about 33 micrograms of bremelanotide and 17 micrograms of oxytocin. The approved bremelanotide dose of 1.75 mg is about 53 units, which also delivers about 0.88 mg of oxytocin.
Is injected oxytocin the same as the nasal spray in the studies?
No, and the difference matters. The research suggesting oxytocin affects social and emotional behaviour uses intranasal delivery because oxytocin injected into the bloodstream reaches the brain poorly.
Is bremelanotide approved?
Yes, for hypoactive sexual desire disorder in premenopausal women, on the basis of two randomised phase 3 trials. This blend is not the approved product.
Why does it make me nauseous?
Nausea is a class effect of melanocortin receptor agonism and appears in the controlled trials of this drug family, including the melanotan II crossover study.