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The Desire Drug

PT-141

Also known as Bremelanotide · Vyleesi

Prescription · work with your prescriber

At a glance

What it is
FDA-approved for premenopausal HSDD. Narrow indication, real side effects.
Evidence
Clinical trialsHow the tiers workBremelanotide has clinical trial evidence for one thing: acquired, generalised hypoactive sexual desire disorder in premenopausal women, by subcutaneous injection. Why this tier
Half-life
Approximately 2.7 hours.
Routes
Subcutaneous
Category
Sexual health
FDA
FDA-approved
As of 3 August 2026. What that means
WADA
We do not state a status
Amino acids
7

Putting PT-141 on a schedule, with the vial it comes from and a log of each dose, happens in the app: Claritide for iPhone.

Evidence

Why this tier

Bremelanotide has clinical trial evidence for one thing: acquired, generalised hypoactive sexual desire disorder in premenopausal women, by subcutaneous injection. Every other use is off-label and unstudied: men, postmenopausal women, the compounded intranasal form the telehealth market sells. The label also states that the exact mechanism by which it improves sexual desire is unknown.

Overview

What it is

PT-141, also called bremelanotide and sold as Vyleesi, is an FDA-approved autoinjector for premenopausal women with acquired, generalised hypoactive sexual desire disorder. The indication is much narrower than the marketing around it suggests, and the label is explicit that it is not indicated for postmenopausal women, for men, or to enhance sexual performance. The label is also the source of the correction on this page: bremelanotide’s highest-potency receptor is MC1R, the pigmentation receptor.

Mechanism

How it works

Bremelanotide is a non-selective melanocortin receptor agonist. The label states the potency order explicitly: MC1R, then MC4R, then MC3R, then MC5R, then MC2R. MC4R is the receptor usually invoked to explain effects on sexual desire, and the label is equally explicit that the exact mechanism by which bremelanotide improves desire is unknown, so MC4R involvement is a hypothesis, not a switch anyone has found. MC1R is the receptor on melanocytes that drives pigment production, and it is the one bremelanotide binds most strongly. That is not a footnote; it is the mechanistic origin of the pigmentation side effect.

Dosing

Commonly researched ranges

These are figures reported in published literature and practitioner protocols: a commonly researched range, not a recommendation. Claritide does not tell you what to take.
  • Label dose (Vyleesi)1.75 mg

    As needed, maximum one dose per 24 hours and no more than 8 doses per month · At least 45 minutes before anticipated sexual activity

    Autoinjector into the abdomen or thigh. The monthly ceiling is a label instruction, not a suggestion. The pigmentation figures below are what happens when it is exceeded.

Cycle guidance
Not cycled. It is dosed on demand within a hard ceiling: one dose in 24 hours, no more than eight doses in a month.
Goals
Libido
Legal standing

Where this sits with the FDA

Dated, sourced, and separate from whether it works. Removal from a warning list is not permission to compound.
FDA-approvedas of 3 August 2026 · US

FDA-approved drug product (Vyleesi)

Approved for premenopausal women with acquired, generalised hypoactive sexual desire disorder, explicitly excluding HSDD due to a co-existing medical or psychiatric condition, relationship problems, or drug effects. PT-141 also appears on FDA Import Alert 66-41 red list, which is about unapproved product entering the country, not about the approved autoinjector.

Primary source

How it got here

  1. 21 March 2020

    PT-141 listed on FDA Import Alert 66-41 (CanLab Research), the detention-without-physical-examination list for unapproved new drugs.

Sport

WADA status

The 2026 Prohibited List entered force on 1 January 2026.
We do not state a status

Not named on the 2026 Prohibited List. Bremelanotide holds a US marketing authorisation, so the S0 catch-all does not obviously capture it. We could not determine a classification and do not state one.

We looked and could not resolve it. This is not the same as "not prohibited". Treat it as unresolved and check with your federation before competing.

Reconstitution

There is nothing to mix

Not applicable. None of the published routes for this compound take a diluent, so there is no concentration to calculate and no beyond-use window to track.

Expectations

Week by week

What our material describes people reporting. Individual responses vary widely.
  1. 1
    Within 1 hour of a dose

    Peak plasma concentration. Nausea, if it happens, typically starts inside this window. It affected 40% of patients in trials and 13% needed an anti-emetic.

  2. 2
    2–4 hours after a dose

    Peak of the transient blood-pressure effect: systolic up about 6 mmHg, diastolic up about 3 mmHg, heart rate down about 5 bpm. This is why uncontrolled hypertension and known cardiovascular disease are absolute contraindications.

Tolerability

Side effects

Grouped by how often our sources report them. Percentages appear only where a published trial figure exists.

Common

  • Nausea40% in trialsThe dominant adverse effect. Onset typically within an hour of dosing; 13% of patients required an anti-emetic.
  • Flushing20.3% in trials
  • Injection-site reactions13.2% in trials
  • Headache11.3% in trials
  • Vomiting4.8% in trials
  • Focal hyperpigmentation1% in trialsThis is the figure the community gets backwards. At the label frequency of up to 8 doses per month, focal hyperpigmentation occurred in 1% of patients. When bremelanotide was given daily for 8 consecutive days, it occurred in 38%, including on the face, the gums and the breasts, with higher risk in darker-skinned patients. Resolution was not confirmed in all patients. The dose ceiling is the mitigation.
  • Transient blood pressure increaseSystolic +6 mmHg, diastolic +3 mmHg, heart rate −5 bpm, peaking 2–4 hours after the dose.
Safety

Contraindications and interactions

Do not use if

  • Uncontrolled hypertension: an absolute contraindication on the label
  • Known cardiovascular disease: an absolute contraindication on the label
  • Not indicated for postmenopausal women
  • Not indicated for men
  • Not indicated to enhance sexual performance
  • Not indicated for HSDD caused by a co-existing medical or psychiatric condition, by relationship problems, or by the effects of another medication: the approved indication is acquired, generalised HSDD specifically

Interactions

  • Oral naltrexoneavoid

    The label states bremelanotide may significantly decrease systemic exposure to orally administered naltrexone, which could make a naltrexone regimen fail silently.

  • Other oral medicationscaution

    Bremelanotide may slow gastric emptying and reduce the rate and extent of absorption of concomitantly administered oral drugs.

Absence from this list does NOT mean safety. It means lack of research.

Handling

Storage and cost

Storage
The approved product is a single-use prefilled autoinjector containing a solution. There is nothing to reconstitute, no concentration to calculate, and no beyond-use window to track.
Cost
Not established in available literature
Combinations

Stacks with

Only pairings our own material actually documents. Stacking is the least evidence-based part of this field.

Curated stacks including it

Deep dive

PT-141 in full

The correction that makes this page worth reading

The widely repeated story about PT-141 is that it was engineered away from MC1R, the pigmentation receptor, so that, unlike Melanotan II, it does not tan you.

The label says the opposite. Bremelanotide's receptor potency order, stated on the approved US prescribing information, is MC1R, MC4R, MC3R, MC5R, MC2R. MC1R is first. It is the receptor bremelanotide binds most strongly.

And the pigmentation is documented, with numbers. At the label's frequency, up to eight doses a month, focal hyperpigmentation occurred in 1% of patients. When the drug was given daily for eight consecutive days, it occurred in 38%, including on the face, the gums and the breasts. Darker-skinned patients were at higher risk. Resolution was not confirmed in all patients.

That is why the ceiling of eight doses per month is on the label, and it is why publishing "PT-141 doesn't cause tanning" would tell a reader that a documented, sometimes-permanent pigmentation risk is not real.

What it is approved for

Premenopausal women with acquired, generalised hypoactive sexual desire disorder. Acquired means it developed after a period of normal function. Generalised means it is not situation-specific. The label then excludes HSDD due to a co-existing medical or psychiatric condition, due to relationship problems, or due to the effects of a medication.

It is explicitly not indicated for postmenopausal women, for men, or to enhance sexual performance. Those three exclusions cover most of the market for it.

How it is dosed

1.75 mg subcutaneously by autoinjector into the abdomen or thigh, at least 45 minutes before anticipated sexual activity. Maximum one dose per 24 hours. More than eight doses per month is not recommended.

Half-life is about 2.7 hours, peak concentration about an hour after dosing, and subcutaneous bioavailability is close to 100%. The 45-minute lead time is a pharmacokinetic instruction, not a ritual.

The side-effect profile is not mild

Nausea affected 40% of patients, and 13% needed an anti-emetic for it. Flushing 20.3%, injection-site reactions 13.2%, headache 11.3%, vomiting 4.8%. There is a transient rise in blood pressure, peaking two to four hours after the dose: systolic up about 6 mmHg, diastolic about 3 mmHg, heart rate down about 5 bpm.

Uncontrolled hypertension and known cardiovascular disease are absolute contraindications on the label. That is not a caution to weigh; it is a line.

Interactions worth knowing

Bremelanotide may significantly decrease systemic exposure to orally administered naltrexone. If someone is on naltrexone for alcohol or opioid use disorder, that is a serious interaction: the medication can stop working without any obvious sign. It may also slow gastric emptying and reduce the rate and extent of absorption of other oral drugs.

The intranasal problem

The telehealth and compounding market sells intranasal PT-141. That is the formulation the developer abandoned. In 2007 FDA placed a clinical hold on the intranasal bremelanotide programme after Phase 3 trials in male erectile dysfunction showed dose-dependent blood-pressure elevations, with wide variability in bioavailability by that route potentially exposing some patients to supra-efficacious levels. Palatin reformulated for subcutaneous injection and that is the form that was eventually approved.

We could not retrieve a primary FDA hold letter, so treat the detail as partial, but the direction is consistent across sources and it matches the blood-pressure warning that made it onto the approved label.

One naming note

"The Barbie peptide" belongs to Melanotan II, not to PT-141. The nickname transfers between the two compounds in community writing and it transfers the wrong expectations with it.

References

Sources

  1. 1
    Vyleesi (bremelanotide) · US prescribing information, DailyMed
    Source
  2. 2
    FDA Import Alert 66-41 · detention without physical examination of unapproved new drugs
    Source
  3. 3
    Palatin Technologies · Phase 2 of bremelanotide co-administered with a PDE5 inhibitor (no topline located)
    Source

Every record in this library is free to read, and it stays free. Your own schedule, vials and log live in the app: Claritide for iPhone.