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PT-141
A melanocortin receptor agonist with one approved use and a disputed effect size. It has one pairing in this atlas from a study that gave two compounds to the same subjects.
The basics
| Human protocol on record | 6 figures |
|---|---|
| Animal or laboratory figures | 0 |
| Published records retrieved | 27 |
| Registered trials | 14 |
| Certificate of analysis | Published by the partner |
| Regulatory status | Has an approved label for one specific indication, which is not approval for any other purpose |
1. The protocol on record
Hard disclaimer. Figures below are transcribed from a published study or an approved label exactly as the source states them. They record what researchers administered in a trial population, not instructions for any person, and none of it is adjusted to you. Most compounds here have no approved human use. Do not act on any of it without a licensed prescriber who knows your history.
Amounts and schedules, human record
| Phase or model | Amount | Frequency | Timing | Route | Duration | Source |
|---|---|---|---|---|---|---|
| FDA-approved use in premenopausal women with hypoactive sexual desire disorder, recommended dosage as stated in a 2022 review (approved brand named Vyleesi in the record) | 1.75 mg | not stated | at least 45 min before sexual activity | subcutaneous, in the abdomen or thigh | not stated | source |
| Phase 1/2 dose-ranging trial, healthy male subjects | 0.3 to 10 mg | not stated | not stated | subcutaneous | not stated | source |
| Phase 1/2 trial, healthy male subjects, threshold for a statistically significant erectile response | greater than 1.0 mg | not stated | not stated | subcutaneous | not stated | source |
| Phase 1/2 crossover trial, patients with erectile dysfunction and an inadequate response to sildenafil | 4 or 6 mg | not stated | not stated | subcutaneous | not stated | source |
| Phase 1 trial, healthy males and sildenafil-responsive erectile dysfunction patients, threshold for a statistically significant erectile response | greater than 7 mg | not stated | not stated | intranasal | not stated | source |
| Randomized crossover trial, 19 erectile dysfunction patients, co-administration arm with 25 mg sildenafil | 7.5 mg | not stated | not stated | intranasal | not stated | source |
Half-life and why the schedule looks like that
- In a phase 1 study of intranasal PT-141 in healthy males and Viagra-responsive erectile dysfunction patients, median T(max) was 0.50 h and mean half-life t(1/2) ranged from 1.85 to 2.09 h. Onset of the first erection occurred in approximately 30 min after intranasal administration (PMID:14963471). - The record states an on-demand schedule rather than a half-life for the approved use: the recommended dosage is 1.75 mg injected subcutaneously in the abdomen or thigh at least 45 min before sexual activity (PMID:35076581). A first-approval review describes bremelanotide as a self-administered, on-demand subcutaneous therapy (PMID:31429064). - No clearance figure and no half-life for the subcut
Handling and storage
- Lyophilised storage: Not stated in the cited record. - Storage after reconstitution: Not stated in the cited record. - Temperature: Not stated in the cited record. - Light: Not stated in the cited record. - Stability duration: Not stated in the cited record. The only administration detail on record is the injection site for the approved 1.75 mg dose, the abdomen or thigh (PMID:35076581).
These figures summarise what published research and approved labels describe. They are educational, not a recommendation or a personal protocol. Any dose, schedule, or decision to use a compound belongs with a licensed prescriber.
Open the interactive builder for reconstitution maths and a calendar →
2. Safety and harm reduction
Reported adverse effects
| Effect | How often reported | Population | Source |
|---|---|---|---|
| Nausea | 40.0% on bremelanotide vs 1.3% on placebo | Integrated double-blind portion of phase 3 studies (N = 1247), premenopausal women with hypoactive sexual desire disorder | PMID:35147466 |
| Flushing | 20.3% on bremelanotide vs 1.3% on placebo | Integrated double-blind portion of phase 3 studies (N = 1247), premenopausal women with hypoactive sexual desire disorder | PMID:35147466 |
| Headache | 11.3% on bremelanotide vs 1.9% on placebo | Integrated double-blind portion of phase 3 studies (N = 1247), premenopausal women with hypoactive sexual desire disorder | PMID:35147466 |
| Injection site reactions | 5.4% on bremelanotide vs 0.5% on placebo | Integrated double-blind portion of phase 3 studies (N = 1247), premenopausal women with hypoactive sexual desire disorder | PMID:35147466 |
| Nausea as reason for discontinuation | Most common reason for bremelanotide discontinuation | Phase 3 studies, clinical development program | PMID:35147466 |
| Focal hyperpigmentation | Rare when dosed per label recommendations; occurred in more than one-third of subjects after up to 16 consecutive daily dosings | Clinical development program (phases 1 through 3) | PMID:35147466 |
| Blood pressure increase | Small, transient, but statistically significant increases on ambulatory blood pressure monitoring | Clinical development program (phases 1 through 3) | PMID:35147466 |
| Serious adverse events | A few subjects; no deaths | Clinical development program, 3500 subjects in 43 completed studies | PMID:35147466 |
| Flushing and nausea | The most common adverse events in both studies | Phase 1 trials, intranasal PT-141, healthy males and Viagra-responsive erectile dysfunction patients | PMID:14963471 |
| Nausea | 40%, described as the most common adverse reaction | Review of clinical trials in premenopausal women with hypoactive sexual desire disorder | PMID:36242769 |
| Discontinuation due to adverse events | Substantially higher on bremelanotide than placebo (OR = 11.98, 95% CI 3.74 to 38.37, NNH 6) | Re-analysis of two 24-week phase 3 trials in women with hypoactive sexual desire disorder | PMID:33678061 |
Cautions stated in the literature
- Bremelanotide should be used with caution in patients at risk of cardiovascular disease, and blood pressure should be well controlled during treatment; small, transient, but statistically significant blood pressure increases were observed on ambulatory monitoring (PMID:35147466).
- Most drug-drug interactions were not clinically significant, except for interactions that lowered plasma concentrations of indomethacin and naltrexone (PMID:35147466).
- Focal hyperpigmentation occurred in more than one-third of subjects following up to 16 consecutive daily dosings, though it was rare when dosed in accordance with label recommendations (PMID:35147466).
- A review of melanocortin agonists reports that bremelanotide was well tolerated and not associated with the hypotension observed with phosphodiesterase-5 inhibitors (PMID:17584134). This is a report of what was not observed in that clinical experience, not a guarantee.
- A lactation study (single dose of Vyleesi in lactating female subjects to measure bremelanotide concentration in breast milk) is registered as completed; the stored record states no results (NCT06867835).
Stop and get help
- Any severe or worsening reaction after administration.
- Signs of an allergic reaction, such as rash, swelling of the face or throat, or difficulty breathing.
- Signs of injection-site infection, such as spreading redness, warmth, pain, or discharge at an injection site.
- New or worsening cardiovascular symptoms, such as chest pain, palpitations, faintness, or symptoms of elevated blood pressure.
- Anything unexpected that persists.
Pairings
Co-administered
PT-141 and Tirzepatide
A registered trial has begun giving both compounds to the same subjects. No result has been reported, so the pairing is a registration, not a finding.
Open the pairing brief →PT-141 at Peptara Labs
Open the PT-141 pageRead the third-party certificate of analysis before anything else. Research-grade material, research use only.