Erections in men, subQ phase 1/2 trial
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Strong human trialsFDA approved as Vyleesi
PT-141
Also known as: Bremelanotide · Vyleesi · PT141
Updated 29 sources
PT-141, or bremelanotide, is a 7-amino-acid peptide that turns up sexual desire through melanocortin receptors in the brain. It is FDA approved as Vyleesi, a 1.75 mg shot women take at least 45 minutes before sex, no more than once a day and 8 times a month. Men use it off label at 1 to 3 mg, often with Cialis. The trade-off is nausea: 40% got it in the phase 3 trials. Frequent dosing also darkens skin.
Quick facts
- Half-life
- About 2.7 hours (range 1.9 to 4.0) after a subQ shot, peaking around 1 hour. SubQ bioavailability is about 100%.
- Routes
- Subcutaneous injection
- Nasal
- Forms
- Prefilled pen
- Vial (powder)
- Nasal spray
- Other form
- Reported dose ranges
- 0.3 to 10 mg (subcutaneous injection)
- 7.5 to 20 mg (nasal)
- 500 to 1,500 mcg (subcutaneous injection)
- Vial sizes
- 10 mg
- FDA status
- FDA approved as Vyleesi
- Brand names
- Vyleesi (Cosette Pharmaceuticals): 1.75 mg autoinjector, used as needed before sex, for premenopausal women with acquired, generalized HSDD.
- WADA
- Not confirmed
What people use PT-141 for
- Low sexual desire in premenopausal women (HSDD), the only approved use
- Male libido and erections, often in men already on TRT or a PDE5 inhibitor, including PDE5 non-responders
- On-demand use by couples for planned nights
- Libido lost on GLP-1 drugs or SSRIs, a frequent question in r/Peptides threads
- Low libido after menopause, mentioned by users even though the label excludes postmenopausal women
How it is thought to work. A 7-amino-acid cyclic peptide modeled on the hormone alpha-MSH. It switches on melanocortin receptors in the brain, mainly MC3R and MC4R, which drive desire and arousal. That makes it a brain drug, not a blood-flow drug like Viagra or Cialis. It came out of the melanotan II line with the tanning effect turned down, though dark skin patches still show up with frequent dosing.
PT-141 dosing
9 protocols from studies, guides and community reports, grouped by goal. Tap a source badge to see where a number came from.
Erections in men2
Erections in men, intranasal trials
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Other protocols: injected (prefilled pen)1
Low sexual desire in women, Vyleesi label dose
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Other protocols: injected5
Women, label dose from a vial (guides)
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Men, on-demand dose (guides)
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First dose or tolerance test (guides)
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Men and couples, community use
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Daily step-up protocol (guide outlier)
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Other protocols: nasal, nasal spray1
Men who failed sildenafil, intranasal trial
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Doses shown are what sources report, labelled by origin. Not medical advice.
Full PT-141 dosage guideEvery titration step in syringe units, missed doses and how to mix.Vial strengths and syringe units
Every PT-141 vial size with the water volumes sources use. Units are what to draw on a U-100 insulin syringe, worked out exactly.
| Water | Strength | 0.5 mgdose, units | 1 mgdose, units | 1.75 mgdose, units |
|---|---|---|---|---|
| 10 mg vial | ||||
| 1 mLCompetitor guide | 10 mg/mL | 50.05 mL | 100.1 mL | 17.50.175 mL |
| 2 mLCompetitor guide | 5 mg/mL | 100.1 mL | 200.2 mL | 350.35 mL |
| 2.5 mLCompetitor guide | 4 mg/mL | 12.50.125 mL | 250.25 mL | 43.80.438 mL |
| 3 mLCompetitor guide | 3.333 mg/mL | 150.15 mL | 300.3 mL | 52.50.525 mL |
Units are on a U-100 insulin syringe (100 units = 1 mL). U-50 and U-30 barrels read the same units.Water volumes from
Doses shown are what sources report, labelled by origin. Not medical advice.
Calculate with this peptideYour vial, your water, your dose: PT-141 in syringe units, with the math shown.What people report
What PT-141 users write on Reddit, counted post by post. These are reports, not measured rates or advice.
Community-reportedFrom 555 Reddit posts and comments, last mined Oct 23, 2026r/Peptides, r/Biohackers, r/Peptidesource, r/PeptideDiscussion
Doses people report for PT-141
Sexual health97 mentions
| Reported | Mentions |
|---|---|
| 1 mg | 37 |
| 0.5 mg | 24 |
| 1.5 mg | 14 |
| 2 mg | 13 |
| 250 mcg | 7 |
Goal not stated20 mentions
| Reported | Mentions |
|---|---|
| 0.5 mg | 7 |
| 1 mg | 4 |
| 1.5 mg | 3 |
| 10 mg | 3 |
| 3 mg | 2 |
Left out: 2 mentions given in syringe units, which mean different doses in different mixes.
How often
| Reported | Mentions |
|---|---|
| As needed | 6 |
| Once a week | 4 |
| Every third day | 3 |
| Once a day | 2 |
| Twice a week | 2 |
Most mentioned alongside
- Melanotan II5
- Tadalafil4
- Oxytocin4
- Sildenafil3
- Semax3
- Retatrutide3
Side effects people mention
Nausea61 mentions
Most common fixes: take zofran (6), lower the dose (4)
Flushing41 mentions
Headache11 mentions
Side effects10 mentions
Skin darkening6 mentions
Fatigue6 mentions
Doses shown are what sources report, labelled by origin. Not medical advice.
PT-141 side effects
What trials and labels report, kept apart from what users and guides report. Frequencies are worded as each source states them.
Reported in studies and labels6
From clinical trials and regulatory documents.
Nausea
40.0% vs 1.3% on placebo in phase 3. Starts within about 1 hour, lasts about 2. Hit 21% after the first dose, about 3% later; 8% quit over it.
How people manage it
- The label allows an anti-nausea drug; 13% of trial users took one.
Flushing
20.3% on bremelanotide vs 0.3% on placebo in phase 3 (1.75 mg).
Injection-site reactions
13.2% on bremelanotide vs 8.4% on placebo in phase 3 (1.75 mg).
Headache
11.3% on bremelanotide vs 1.9% on placebo in phase 3 (1.75 mg).
Vomiting
4.8% on bremelanotide vs 0.2% on placebo in phase 3 (1.75 mg).
Cough
3.3% on bremelanotide vs 1.3% on placebo in phase 3 (1.75 mg).
Reported by users and guides3
From community reports and dosing guides. Not measured rates.
Lower appetite
A mild appetite drop, reported in one r/Peptides comment.
Nausea, headache and injection-site irritation (community logs)
The most logged side effects in one site's user logs. On r/Peptides, headache and nausea are the main complaints, and some users quit over them. Users also describe hot eyes.
How people manage it
- Start very low and work up, the standard r/Peptides advice after a bad first dose.
Dark spots at low, frequent doses (community report)
One r/Peptides user reported new moles, dark spots and darker under-eye circles after under 1 mg every other day for 4 days.
Who should avoid it
Uncontrolled high blood pressure or known cardiovascular diseaseCondition
PT-141 raises blood pressure for a few hours after each dose. The label says not to use it with uncontrolled hypertension or known heart disease.
Oral naltrexoneSubstance
Bremelanotide can sharply cut naltrexone levels in the blood, which can make naltrexone fail, per the label.
Melanotan IISubstance
Both hit the same melanocortin receptors. Guides warn against stacking two melanocortin agonists.
Storage
Powder (before mixing)
- Temperature
- -20 to 8 °C
Freeze the powder at -20 C for long storage; the fridge is fine short term. One guide gives 18 to 24 months at 2 to 8 C.
Mixed vial
- Temperature
- 2 to 8 °C
- Use within
- 28 days
Keep the mixed vial at 2 to 8 C and do not freeze it. Guides say several weeks, 14 to 30 days, or 28 days. No stability study backs any of these.
As supplied
Vyleesi pens: store at or below 25 C (77 F). Do not freeze, and protect from light.
Mixing. 2 mL in a 10 mg vial is the most common mix, giving 5 mg per mL, so the 1.75 mg label dose is 0.35 mL. That is more than a 0.3 mL syringe holds, so use a 0.5 or 1 mL syringe. The Vyleesi pen is premixed and needs no water.
Stacks people report
Combinations from guides and community posts, with the reason given.
- Sildenafil
Desire from PT-141 plus blood flow from a PDE5 drug. In a trial, 7.5 mg nasal PT-141 plus 25 mg sildenafil beat sildenafil alone.
- Tadalafil
Many male users on r/Peptides already take daily Cialis and add PT-141 on demand for the desire side.
Kisspeptin supports the hormone axis (LH and testosterone) while PT-141 handles on-demand desire, as r/Peptides users describe it.
Added for the bonding and feelings side of intimacy, per an r/Peptides user.
One guide suggests BPC-157 before PT-141 to blunt nausea, and admits there is no data behind it.
Not synergy, just overlap: retatrutide is the compound most often logged alongside PT-141 in one site's user logs, and GLP-1 users who lose libido ask about PT-141.
Compare PT-141
Evidence and legal status
Evidence: strong human trials
About 3,500 people across 43 studies. Two phase 3 trials in 1,267 women showed small but real gains in desire and less distress; about 25% vs 17% on placebo improved meaningfully, but satisfying sexual events did not rise. 18% quit over side effects vs 2% on placebo. Male data is limited to phase 1/2 trials, and the main non-responder trial has an expression of concern.
FDA and WADA
FDA approved as Vyleesi
Approved by the FDA, but for a narrower use than people take it for here.
FDA approved on June 21, 2019 as Vyleesi, a 1.75 mg autoinjector for premenopausal women with acquired, generalized HSDD. Not approved for men, postmenopausal women or performance use.
Research vials and compounded nasal or oral products are not the approved product. Telehealth services sell compounded versions. We found no FDA bulk-substance category for bremelanotide, and we could not confirm whether WADA names it.
WADA: Not confirmed
PT-141 questions
What is the PT-141 dose for women?
The FDA label dose is 1.75 mg injected under the skin of the belly or thigh, at least 45 minutes before sex. That is the Vyleesi autoinjector. Guides for research vials repeat the same 1.75 mg.
What is the PT-141 dose for men?
No dose is approved for men. Guides say start at 1 mg and go up to 2 mg if needed. Community dose logs cluster at 2 to 3 mg. Early trials found erections improved above 1 mg subQ, and gave men with ED 4 or 6 mg.
How long before sex should I take PT-141?
The label says at least 45 minutes. Guides for men say 1 to 2 hours. Blood levels peak about 1 hour after a subQ shot.
How long does PT-141 last?
The half-life is about 2.7 hours after a subQ shot. Guides claim 6 to 12 hours of effect, without a source.
How often can I take PT-141?
The label allows no more than 1 dose in 24 hours and does not recommend more than 8 doses a month. In the phase 3 trials most people used it 2 to 3 times a month.
Why does PT-141 cause nausea, and how do I stop it?
Nausea hit 40% of women in the phase 3 trials, usually within an hour and lasting about 2 hours. It was worst after the first dose (21%) and dropped to about 3% on later doses. The label allows an anti-nausea drug, and 13% used one. Guides suggest starting at 0.5 to 1 mg, taking ondansetron 30 minutes before, eating a light meal 1 to 2 hours before, and staying hydrated.
Does PT-141 darken your skin?
Rarely at label use, often with daily use. Dark patches on the face, gums or breasts showed up in 1% of people at up to 8 doses a month, but in 38% after 8 daily doses in a row. They are more likely with darker skin and do not always fade.
How much water do I add to a 10 mg PT-141 vial?
2 mL is the common choice, giving 5 mg per mL, so 1.75 mg is 0.35 mL. Guides also use 1, 2.5 or 3 mL. Use the calculator for your exact vial and dose.
Does nasal PT-141 work?
The trials that worked nasally used 7 to 20 mg, far more than the 1.75 mg shot. In one label study, 20 mg nasal reached about 2.5 times the peak level of a shot. Nasal doses peak at about 30 minutes, with a half-life of 1.85 to 2.09 hours. Spray products vary in how much each spray delivers, and one couple on r/Peptides found nasal did nothing while subQ worked.
Can I take PT-141 with Cialis or Viagra?
A trial combined 7.5 mg nasal PT-141 with 25 mg sildenafil and found it beat sildenafil alone, without new side effects. Keep in mind PT-141 raises blood pressure for a few hours.
Is PT-141 safe with high blood pressure?
The label says not to use it with uncontrolled high blood pressure or known heart disease. Each dose raises blood pressure by about 6/3 mmHg at its peak, 2 to 4 hours after the shot, and lowers heart rate by up to 5 beats a minute. Both usually return to baseline within 12 hours.
Is PT-141 FDA approved?
Yes, as Vyleesi, approved in June 2019 for premenopausal women with acquired, generalized low sexual desire. It is not approved for men, for postmenopausal women, or as a performance enhancer. Research vials and compounded sprays are not the approved product.
Where do you inject PT-141?
Under the skin of the abdomen or thigh, per the label.
Can I take PT-141 with naltrexone?
Not with oral naltrexone. The label says bremelanotide can sharply cut naltrexone levels, which can make it stop working.
Ask about PT-141
Answers come from this site's pages only, with a link to each source.
Sources
29 sources, each checked by date. Record updated Oct 23, 2026. Numbers are restated in our own words and labelled by where they came from.
Clinical study8
- Bremelanotide: first approval (Drugs 2019)PubMed · checked Oct 23, 2026
- Subcutaneous PT-141 in healthy men and Viagra non-responders (Int J Impot Res 2004)PubMed · checked Oct 23, 2026
- Intranasal PT-141 in healthy men and patients with erectile dysfunction (Int J Impot Res 2004)PubMed · checked Oct 23, 2026
Regulatory3
- Vyleesi (bremelanotide) prescribing information, 2019FDA · checked Oct 23, 2026
- Vyleesi label (current)DailyMed · checked Oct 23, 2026
- FDA approves Vyleesi for women with low sexual desireHealio, via a news report · checked Oct 23, 2026
Competitor guide6
- Bremelanotide (PT-141) protocolpeptidedosingprotocols.com · checked Oct 23, 2026
- PT-141 10 mg vial dosage protocolpeptidedosages.com · checked Oct 23, 2026
- PT-141peptiq.io · checked Oct 23, 2026
Community-reported12
- Comment: nasal failed, subQ worked; compounded productsr/Peptides · checked Oct 23, 2026
- Comment: about 2 mg doser/Peptides · checked Oct 23, 2026
- Comment: 1.0 mg instead of 1.75 mg; oxytocinr/Peptides · checked Oct 23, 2026