PT-141 dosage is an as-needed timing decision, not a daily schedule. The brand Vyleesi label uses a fixed 1.75 mg subcutaneous dose at least 45 minutes before anticipated sexual activity, with no more than one dose in 24 hours and no more than eight doses per month. That label does not establish the right dose for a compounded prescription. The prescriber sets the actual amount and timing from the patient's history, other medicines, tolerability and response.
The PT-141 dosage evidence at a glance
PT-141 is another name for bremelanotide, a melanocortin-receptor agonist. Its dosing evidence comes from a dose-finding study, the two phase 3 RECONNECT trials and the Vyleesi prescribing label. These are related sources, but they answer different questions.
| Evidence | Amount evaluated | Schedule studied or labeled | What it establishes |
|---|---|---|---|
| Phase 2 dose-finding trial | 0.75, 1.25 or 1.75 mg | Subcutaneous, as desired, about 45 minutes before anticipated activity | 0.75 mg did not separate from placebo; the two higher groups informed phase 3 selection |
| RECONNECT phase 3 trials | 1.75 mg | Subcutaneous, as needed, for 24 weeks | The registration-trial regimen in premenopausal women with acquired, generalized HSDD |
| Vyleesi label | 1.75 mg in 0.3 mL | At least 45 minutes beforehand; no more than once per 24 hours or eight times per month | The approved brand's fixed-dose instructions |
| Compounded bremelanotide | Set by the prescription | Set by the prescriber and pharmacy label | A separate formulation whose concentration and prescribed amount should not be inferred from the brand pen |
The current Vyleesi label also says the optimal administration window and the duration of efficacy have not been fully characterized. That is why 45 minutes is a labeled minimum, not a promise that every patient experiences the same onset.
Brand Vyleesi and compounded PT-141 are not interchangeable
As of August 2026, Promise's bremelanotide is dispensed as a compounded medication, which is different from an FDA-approved product: the formulation offered here is not FDA-approved; by contrast, the FDA-approved brand Vyleesi is indicated for acquired, generalized hypoactive sexual desire disorder in premenopausal women. The FDA approval labeling says it is not indicated for postmenopausal women, men or enhancement of sexual performance.
The distinction matters in a dosage article. A Vyleesi autoinjector contains one fixed 1.75 mg dose in 0.3 mL. A compounded vial can have a different concentration and delivery device. The number printed on a syringe therefore cannot be translated into milligrams without the pharmacy label. The prescription, not an online conversion, defines the dose.
FDA status is one input to care, and a licensed provider may still prescribe a compounded formulation when medically appropriate; that decision is between the patient and the doctor.
What the RECONNECT trials used
RECONNECT consisted of two identically designed, randomized, placebo-controlled phase 3 trials. The investigators randomized 1,267 premenopausal women with HSDD and evaluated bremelanotide 1.75 mg given subcutaneously as needed over 24 weeks. The regimen improved the trials' measures of sexual desire and distress relative to placebo, while nausea, flushing and headache occurred more often with bremelanotide (Kingsberg et al., Obstetrics & Gynecology, 2019).
Those trials establish what was tested for the approved population. They do not establish a universal PT-141 dose for men, postmenopausal women or people using a compounded formulation. The PT-141 mechanism explainer covers what the melanocortin pathway does; dose selection is narrower and depends heavily on tolerability.
How long does PT-141 last?
There is no well-established single duration for the clinical effect. The label reports that blood concentrations peak at a median of about one hour and that bremelanotide has a mean terminal half-life of about 2.7 hours. Neither number is a stopwatch for desire or response. Pharmacokinetics describe drug concentration, while the felt effect can vary between people.
The 24-hour interval in the label is also not a claim that PT-141 lasts 24 hours. It is a safety boundary: closer repeat doses have not been shown to add benefit and could add blood-pressure effects. Timing before anticipated activity, rather than a daily clock, is the variable a prescriber adjusts around response and adverse effects.
Why nausea and flushing shape dose selection
The phase 2 dose-finding study randomized 397 women to placebo or 0.75, 1.25 or 1.75 mg. Nausea was reported by 18%, 22% and 24% across the three active-dose groups, compared with 3% on placebo. Flushing occurred in 17%, 14% and 17%, compared with none on placebo (Clayton et al., Women's Health, 2016). Nausea showed a modest upward dose pattern; flushing was common across active doses but did not rise in a clean dose-response line.
In the pooled phase 3 label data at 1.75 mg, nausea occurred in 40% of participants and flushing in 20.3%. Nausea usually began within an hour and had a median duration of about two hours; 8% discontinued because of it. The label also describes a temporary blood-pressure rise, generally returning to baseline within 12 hours, and contraindicates Vyleesi in uncontrolled hypertension or known cardiovascular disease.
For compounded care, those findings explain why a prescriber may consider tolerability when choosing a starting amount. They do not create a validated do-it-yourself low-dose protocol.
What the prescriber weighs
A dosing decision starts with whether bremelanotide fits the clinical question at all. The Vyleesi trials enrolled premenopausal women with acquired, generalized HSDD; they were not general libido or performance studies. Cardiovascular history and blood pressure matter because of the transient rise after dosing. Pregnancy potential, kidney or liver impairment, nausea history and other oral medicines also affect the review. Bremelanotide can slow gastric emptying, and the label flags a clinically important interaction with oral naltrexone.
At Promise, a licensed provider reviews every request and determines whether PT-141 and a particular dose are appropriate; not everyone qualifies. The PT-141 product page begins that compound-specific intake, while the guide to prescribed peptides explains what happens between intake, provider review and pharmacy dispensing.
The useful answer is on the prescription label
The evidence gives a clear reference point: 1.75 mg as needed was the phase 3 and brand-label regimen, and the label uses a minimum 45-minute lead time with firm frequency limits. It does not turn that regimen into instructions for every compounded vial. Concentration, delivery device, medical history and tolerability can all change what a prescriber writes. For an individual prescription, the pharmacy label is the source of truth.