Important limitations
- Individual claims and source links have not yet completed editorial verification.
- Evidence level, applicable study model, formulation, route and population remain unassigned.
PT-141
PT-141, generic name bremelanotide, is a cyclic seven-residue analog of alpha-melanocyte-stimulating hormone developed by Palatin Technologies.
Dosing & scaling, explained
The moderated mass amounts below are retained for comparison. Near-duplicates, mix-dependent volumes and device markings are excluded. This is educational source context, not a protocol or recommendation.
Mass amounts available for comparison
- Lower range1 mgTypical Dose
Recorded example with no verified study backing; shown for amount literacy only.
- Mid range4 mgTypical Dose
Recorded example with no verified study backing; shown for amount literacy only.
Only mcg or mg amounts are retained. The calculator derives mL, syringe units or pen clicks from the current vial strength, water volume and device.
No independently verified schedule
Evidence context
No clinical amount or schedule is inferred from this material. Source verification is pending, and every displayed amount remains educational context rather than guidance.
Storage, handling and interpretation
Product identity
Verify the exact compound, formulation and amount against the product label or certificate before calculation.
Storage & handling
Follow the product label, certificate and validated laboratory SOP; no universal storage assumption is applied here.
Prepared solutions
Label concentration and preparation date, use sterile technique where applicable, and follow a validated stability protocol.
Reported protocols for PT-141
What published studies and recent community write-ups report about amounts, timing and course length. 6 clinical, 1 preclinical and 4 community-reported rows, each linked to its source. These are descriptions of what others report, not instructions, and nothing here is medical advice.
| Context | Dose | Frequency | Route | Course | Source |
|---|---|---|---|---|---|
| Clinical6 rows | |||||
| FDA label, Vyleesi autoinjectorPremenopausal women with acquired, generalized hypoactive sexual desire disorder | 1.75 mg (0.3 mL autoinjector) | As needed, at least 45 minutes before anticipated sexual activity; no more than one dose in 24 hours and no more than 8 doses per month | Subcutaneous, abdomen or thigh | On demand; the label directs stopping after 8 weeks if symptoms have not improvedAt least 24 hours between doses; the monthly cap is the only other limit described | DailyMed, National Library of Medicine2024 |
| The label states that the duration of effect after each dose is unknown and that the optimal timing window has not been fully characterized, so patients are told to judge timing from their own experience. It caps monthly use because focal hyperpigmentation appears to be cumulative and because each dose transiently raises blood pressure. | |||||
| Phase 3 RECONNECT trials1,267 premenopausal women with hypoactive sexual desire disorder, mean age 39 | 1.75 mg | As needed, self-administered about 45 minutes before anticipated sexual activity, no more than once in 24 hours | Subcutaneous autoinjector, at home | 24 weeks of double-blind treatment after a 4-week placebo baseline periodNone described; an optional 52-week open-label phase followed | Obstetrics and Gynecology (PubMed)2019 |
| Two identically designed trials found increases in the desire domain score of 0.30 and 0.42 and reductions in desire-related distress of 0.37 and 0.29 against placebo. The absolute differences are small, and nausea, flushing and headache each affected 10% or more of treated participants in both studies. | |||||
| Phase 3 registration and open-label extension723 premenopausal women randomized in study 301 | 1.75 mg fixed dose | As needed, no more than one dose every 24 hours | Subcutaneous autoinjector | 24 weeks, then 52 weeks of open-label treatment for those who continuedNone; the 24-hour minimum interval was the only restriction in the protocol | ClinicalTrials.gov2014 |
| The registration record shows that no dose titration was used at any point: everyone who received drug received the same 1.75 mg amount for up to 76 weeks in total. It also confirms the 4-week no-treatment qualification period and 4-week single-blind placebo run-in that preceded randomization. | |||||
| Phase 2b dose-finding trial327 premenopausal women with hypoactive sexual desire disorder, female sexual arousal disorder or both | 0.75, 1.25 or 1.75 mg | As desired, about 45 minutes before anticipated sexual activity | Subcutaneous, prefilled 0.3 mL syringe into the anterior thigh or abdomen | 12 weeks, after an in-clinic single-blind placebo dose and a 4-week at-home placebo baselineNone described | Women's Health (PubMed)2016 |
| The pooled 1.25 and 1.75 mg arms gained 0.7 satisfying sexual events per month against 0.2 on placebo, and the 0.75 mg arm was not effective. This is the study that selected 1.75 mg for phase 3, and nausea reached 22% to 24% in the two higher arms. | |||||
| Early intranasal dosing in menHealthy men and men with mild to moderate erectile dysfunction who responded to sildenafil | Doses above 7 mg produced a response; no maximum tolerated dose was reached | Single doses | Intranasal | Single-dose pharmacokinetic and pharmacodynamic sessionsNot applicable | International Journal of Impotence Research (PubMed)2004 |
| Erectile response measured by RigiScan became statistically significant against placebo only above 7 mg intranasally, with first erections about 30 minutes after dosing, a median time to peak concentration of 0.5 hours and a half-life of 1.85 to 2.09 hours. Flushing and nausea were the most common events; these intranasal doses are several times the amount later approved for subcutaneous use. | |||||
| Intranasal trial in sildenafil non-responders342 married men aged 28 to 59 with erectile dysfunction that had not responded to sildenafil | 10 mg | 45 minutes to 2 hours before sexual stimulation, for at least 16 attempts | Intranasal spray | At-home use across at least 16 dosing attemptsNone described | Journal of Urology (PubMed)2008 |
| A positive clinical result was recorded in 33.5% of the bremelanotide group against 8.5% on placebo, and intercourse satisfaction scores were higher. Drug-related adverse effects were also significantly more common, and the authors concluded that further work on different doses and regimens was needed; the male program was later discontinued. | |||||
| Preclinical1 row | |||||
| Preclinical rat model of sexual motivationOvariectomized female rats primed with estrogen, or estrogen plus progesterone | 50, 100 or 200 mcg/kg | Single dose, 5 minutes before each behavioral test | Subcutaneous in saline | Single 30-minute test sessionsNot applicable | Proceedings of the National Academy of Sciences (PubMed Central)2004 |
| Solicitation behavior increased significantly at 100 and 200 mcg/kg while lordosis, pacing and general motor activity were unchanged, which the authors read as a selective effect on sexual motivation rather than reflex. This is the rodent work that framed the compound as a desire drug, and it does not translate into a human dose. | |||||
| Community-reported4 rows | |||||
| Off-label male starting dose described by telehealth guides | 1 mg to start, raised to 1.5-1.75 mg if needed | As needed, 45 minutes before activity; the guide suggests keeping to 2 to 3 doses per week at most | Subcutaneous from a compounded 10 mg vial | On demand, with a review at 8 weeks mirroring the labelSame 24-hour and 8-dose-per-month caps as the label | Community resource2026 |
| This 2026 guide says most telehealth protocols open at 1 mg rather than the approved 1.75 mg specifically to gauge nausea, and it reports community use of intranasal doses of 0.5 to 1 mg with less reliable absorption. It presents the compounded male protocol as prescriber convention and notes that PT-141 has no approved indication in men. | |||||
| Compounded prescribing range for men with erectile dysfunction | 0.5-1.25 mg to start, titrated toward 1.75 mg | As needed, 45 to 60 minutes before activity, within the label caps | Subcutaneous, compounded through a 503A or 503B pharmacy | Reassessment at 4 to 6 weeks is described as reasonableOne dose per 24 hours and 8 doses per month, carried over from the label as a precaution | Community resource2025 |
| This clinician-facing page is explicit that the lower male starting range is prescriber judgment rather than published protocol, and that no large randomized trial in men supports any specific figure. It sets out stop points including uncontrolled hypertension, new pigmented lesions and nitrate use. | |||||
| Research-vial reconstitution reference | 1.75 mg per injection | As needed, maximum one dose per 24 hours | Subcutaneous from a vial reconstituted to 1.75-3.5 mg/mL | On demand; up to 8 uses per month as in the trials24-hour minimum interval | Community resource2026 |
| This 2026 reference argues that 1.75 mg is the only dose validated in phase 3 and that doses of 3 mg and above increased nausea, flushing and blood pressure effects without extra benefit. It lists a terminal half-life of about 2.7 hours and subjective effects lasting 2 to 4 hours, and gives 28-day refrigerated stability for bacteriostatic-water reconstitution. | |||||
| Dosing-wiki summary with unit math | 1.75 mg (0.875 mL of a 2 mg/mL solution) | As needed, at least 45 minutes before activity, no more than 8 doses per month | Subcutaneous, abdomen or thigh, rotating sites | Repeatable on demand rather than run as a courseOne dose per 24 hours, described as allowing more than eight half-lives of clearance | Community resource2026 |
| This page gives the reconstitution arithmetic for research vials, where a 10 mg vial in 5 mL of bacteriostatic water yields 2 mg/mL and a dose is 0.875 mL. It lists the gaps honestly, including that nobody has tested whether starting lower reduces nausea and that male dose optimization has never been established. | |||||
How a course is commonly described
- 45 minutes before useClinical
Both the label and the trials put the injection at least 45 minutes ahead of anticipated activity, with peak plasma levels about an hour after a subcutaneous dose. Nausea is the most common reaction and tends to arrive within that first hour.
- First 12 hoursClinical
The label records maximal increases of 6 mmHg systolic and 3 mmHg diastolic blood pressure peaking 2 to 4 hours after a dose, with a matching fall in heart rate, and states that these changes usually resolve within 12 hours. This is the reason no second dose is permitted inside 24 hours.
- First weeks of community useCommunity-reported
Community and telehealth guides describe opening at 1 mg rather than 1.75 mg to judge tolerance, then moving up only if the effect is insufficient. Several report that nausea often eases over the first few doses and suggest keeping use to two or three times a week.
- Across a monthClinical
Use is capped at 8 doses per month. Focal hyperpigmentation of the face, gums or breasts was reported in 1% of patients at up to 8 doses per month in the phase 3 trials, against 38% in a separate study that dosed daily, which is what the monthly ceiling is protecting against.
- Week 8 reviewCommunity-reported
The label directs stopping if symptoms have not improved after 8 weeks of appropriate use, and off-label male protocols are described as mirroring that review point. Nothing in the label or the trials describes a break, a taper or a cycle.
- PT-141 is an on-demand drug rather than a cycled one. There is no titration in the label or the phase 3 protocol: every treated participant used the same 1.75 mg dose, and the only schedule rules are one dose per 24 hours and 8 doses per month.
- Nothing in the approved label applies to men. The male evidence consists of intranasal trials at 10 mg and above from a programme that was discontinued, so compounded subcutaneous doses in men are extrapolated from a female indication.
- The label contraindicates uncontrolled hypertension and known cardiovascular disease because each dose transiently raises blood pressure, and it warns that pigmentary changes may not fully resolve after stopping.
Sources for this section (12)
- VYLEESI (bremelanotide) injection: Prescribing Information
- VYLEESI (bremelanotide) injection: 2019 approval label
- Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials
- Study to Evaluate the Efficacy and Safety of Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder (NCT02333071)
- Bremelanotide for Female Sexual Dysfunctions in Premenopausal Women: A Randomized, Placebo-Controlled Dose-Finding Trial
- Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction
- Salvage of Sildenafil Failures With Bremelanotide: A Randomized, Double-Blind, Placebo Controlled Study
- Selective facilitation of sexual solicitation in the female rat by a melanocortin receptor agonist
Plus 4 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
Overview
PT-141, generic name bremelanotide, is a cyclic seven-residue analog of alpha-melanocyte-stimulating hormone developed by Palatin Technologies. It acts on melanocortin receptors in the brain rather than on blood vessels, which separates it mechanistically from the PDE5 inhibitors used for erectile dysfunction. The FDA approved it in June 2019 as Vyleesi, a 1.75 mg subcutaneous autoinjector for premenopausal women with acquired, generalized hypoactive sexual desire disorder; the label states it is not indicated for postmenopausal women, for men, or to enhance sexual performance. Earlier intranasal development in men with erectile dysfunction was discontinued, so all use in men comes from off-label compounded prescribing rather than an approved indication.
What researchers are exploring
These themes organize the educational information currently available. Individual claims remain under source review and are not treatment claims.
- 1
Research on PT-141
Scientific findings and therapeutic applications
What is known and what still needs verification
Available context is organized without assigning unsupported study models or evidence grades.
- Not graded
Research on PT-141
Scientific findings and therapeutic applications
Amounts recorded for PT-141
These amount records are independent from vial strength, reconstitution volume and measuring device. A recorded source is not the same as study backing, and these values are not recommendations.
- 1Typical DoseSign in for schedule, duration and source context.1 mg
- 2Typical DoseSign in for schedule, duration and source context.4 mg
Chemistry identifiers
Sequence, synonyms and registry identifiers as recorded in PubChem, the National Library of Medicine's open chemistry database. Formula, mass and CAS number are summarized at the top of the page.
Sequence
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]
Also listed as
Vyleesi, Bremelanotide, PT-141, PT-141 free base, UNII 6Y24O4F92S, DrugBank DB11653, CHEMBL2070241, CHEBI:177849
InChIKey
FFHBJDQSGDNCIV-MFVUMRCOSA-N
IUPAC name
(3S,6S,9R,12S,15S,23S)-15-[[(2S)-2-acetamidohexanoyl]amino]-9-benzyl-6-[3-(diaminomethylideneamino)propyl]-12-(1H-imidazol-5-ylmethyl)-3-(1H-indol-3-ylmethyl)-2,5,8,11,14,17-hexaoxo-1,4,7,10,13,18-hexazacyclotricosane-23-carboxylic acid
Limitations and unknowns
Sources
1 link carried over from the earlier page, awaiting verification.