Approved drugMelanocortin-receptor agonist

PT-141

Q: What is the usual PT-141 dose?

From the label (Vyleesi): 1.75 mg at least 45 minutes before sexual activity. No more than 1 dose in 24 hours or 8 doses a month. From community reports, not established: Off-label users often start at 1 mg to gauge nausea. These are the amounts sources reference, not recommendations.

Q: How much water do I mix PT-141 with?

There’s no single right amount, because the water only sets the strength. With 2 mL of bacteriostatic water in a 10 mg vial, the strength is 5 mg/mL, so 1.75 mg is 35 units on a U-100 insulin syringe. More water makes small doses easier to measure. The dose chart above shows other volumes.

Q: What is the half-life of PT-141?

About 2.7 hours, according to the prescribing information. Mean terminal half-life after a single subcutaneous dose, range 1.9 to 4.0 hours.

Q: How should PT-141 be stored?

Not supplied as powder. Vyleesi autoinjectors are stored at or below 25 °C (77 °F), not frozen, protected from light. Single-dose prefilled autoinjector; discard after one use.

Q: Is PT-141 banned in sport?

No. Not named on the 2026 list. As an approved drug (Vyleesi), bremelanotide is outside S0 non-approved substances.

Q: Has PT-141 been studied in people?

Yes. The human studies section lists 3 published studies. The largest, from 2019, included 1,267 people. Desire score rose 0.35 points and distress fell 0.33 points more than placebo (both P<.001); nausea, flushing and headache in 10% or more.

Bremelanotide (Vyleesi)

Common dose: 1.75 mg as needed
Cycle: As needed
Vial sizes: 10 mg
Typical draw: 35 units10 mg with 2 mL, 1.75 mg

A synthetic cyclic peptide that activates melanocortin receptors in the brain to increase sexual desire.

Evidence. FDA-approved in 2019 as Vyleesi for acquired, generalized low sexual desire in premenopausal women. Other use is off-label.

Status

Approval: Approved in the US in 2019 as Vyleesi, a 1.75 mg autoinjector for acquired, generalized low sexual desire (HSDD) in premenopausal women.
Sport (WADA 2026): Not banned in sportNot named on the 2026 list. As an approved drug (Vyleesi), bremelanotide is outside S0 non-approved substances.

Sport status follows the WADA Prohibited List in force since January 1, 2026; athletes should confirm with their anti-doping organization. Checked October 5, 2026.

Protocol

Label

Vyleesi

1.75 mg at least 45 minutes before sexual activity. No more than 1 dose in 24 hours or 8 doses a month.

Community

Off-label users often start at 1 mg to gauge nausea.

Frequency: As needed (max 8 a month)
Route: Subcutaneous injection (abdomen or thigh)
Timing: At least 45 minutes before activity.
Cycle: As needed. Stop after 8 weeks if there’s no improvement (label).
As needed, shown over 26 weeks

Common protocols

The ways PT-141 is most often run, each tagged with where it comes from.

Label dose

Label

Dose: 1.75 mg
How often: As needed, at least 45 min before sex
How long: Reassess at 8 weeks

No more than 1 dose in 24 hours; more than 8 a month isn’t recommended. Stop at 8 weeks if desire hasn’t improved.

Draw 35 units10 mg + 2 mL

Lower first dose

Community

Dose: 1 mg
How often: As needed
How long: First few uses

Off-label habit to gauge nausea. The label dose is 1.75 mg; lower doses aren’t part of the label.

Draw 20 units10 mg + 2 mL

Taking it

Where it goes

Subcutaneous injection into the abdomen or thigh with the autoinjector (label). Off-label vials are injected in the same areas.

If you miss a dose

No missed-dose rule, since it’s used as needed. Never take more than 1 dose in 24 hours, and more than 8 doses a month isn’t recommended (label).

What to expect

First dose
Nausea in 40% (placebo 1.3%). It improves for most people by the second dose.
Label
2–4 hours after a dose
Blood pressure up to 6/3 mmHg higher and heart rate up to 5 beats lower; usually back to normal within 12 hours.
Label
By 8 weeks
If desire hasn’t improved, the label says to stop.
Label

Side effects and what to do

Nausea (label: 40% vs 1.3% placebo)

13% needed anti-nausea medicine and 8% quit. Label: consider stopping if severe or persistent.

Flushing (label: 20%)

Common after a dose. Report it if severe.

Injection-site reactions (13%) and headache (11%)

Rotate sites. Get checked if a site looks infected.

Dark skin patches (label: 1% at up to 8 doses a month; 38% after 8 daily doses)

More likely with frequent dosing and darker skin. May not fade after stopping.

Blood pressure rise

Don’t use with uncontrolled high blood pressure or heart disease (label contraindication).

Stop and get medical help

Get help for hives, swelling or trouble breathing, chest pain, a severe headache, vomiting that won’t stop, or yellow skin or eyes.

Tracking and pairing

Worth tracking

Blood pressure
Nausea after doses
New dark skin patches

Often paired with

Usually run on its own.

Human studies

3 key published human studies, with how many people took part. Animal studies aren’t listed here.

20191,267 people

Desire score rose 0.35 points and distress fell 0.33 points more than placebo (both P<.001); nausea, flushing and headache in 10% or more.

Design
Two randomized controlled trials (RECONNECT)
Dose
1.75 mg subcutaneous as needed
Length
24 weeks

Kingsberg et al., Obstet Gynecol 2019 (RECONNECT 301/302), PMID 31599840
2019684 people

No new safety signals; nausea 40.4%, flushing 20.6%, headache 12.0%; desire and distress gains held (descriptive, no placebo); 272 finished.

Design
Open-label extension
Dose
1.75 mg subcutaneous as needed
Length
52 weeks

Simon et al., Obstet Gynecol 2019 (RECONNECT extension), PMID 31599847
2016327 people

Pooled 1.25 and 1.75 mg: satisfying sexual events rose 0.7 vs 0.2 per month with placebo (p=0.018).

Design
Randomized dose-finding trial (phase 2b)
Dose
0.75, 1.25 or 1.75 mg subcutaneous as desired
Length
12 weeks

Clayton et al., Womens Health (Lond) 2016, PMID 27181790

Mixing your vial

Vial	Water	Common dose	Draw	Strength	Action
10 mg	2 mL	1.75 mg	35 units (0.35 mL)	5 mg/mL

Dose chart

10 mg vial

Syringe units for common doses at different water volumes. Select a cell to open it in the calculator.

Dose	Water added
Dose	1 mL	2 mL	3 mL
1 mg
1.5 mg
1.75 mg

U-100 insulin syringe: 100 units is 1 mL. Draws over 100 units show in mL. Faded values are under 2 units, which is hard to measure. Check that your vial holds the larger volumes.

Datasheet

Half-life: about 2.7 hours LabelMean terminal half-life after a single subcutaneous dose, range 1.9 to 4.0 hours.
Type: Peptide, 7 amino acids
Molecular weight: 1,025.2 g/mol
Formula: C₅₀H₆₈N₁₄O₁₀
Sequence: Ac-[Nle]-cyclo(DH[D-Phe]RWK)-OH
Storage before use: Not supplied as powder. Vyleesi autoinjectors are stored at or below 25 °C (77 °F), not frozen, protected from light.
After mixing or opening: Single-dose prefilled autoinjector; discard after one use.

Half-life: Vyleesi prescribing information, clinical pharmacology (DailyMed, Nov 2025)
Molecule: PubChem CID 9941379 (bremelanotide)
Storage: Label Vyleesi prescribing information, How Supplied/Storage (DailyMed, Nov 2025)

Cautions

Nausea in about 40% of users in trials.
Temporary blood pressure rise. Avoid with uncontrolled high blood pressure or heart disease.
Skin darkening in about 1%, more with frequent dosing.
Sharply lowers blood levels of oral naltrexone.

Questions

What is PT-141?

A synthetic cyclic peptide that activates melanocortin receptors in the brain to increase sexual desire.

Is PT-141 FDA-approved?

Approved in the US in 2019 as Vyleesi, a 1.75 mg autoinjector for acquired, generalized low sexual desire (HSDD) in premenopausal women.

What is the usual PT-141 dose?

From the label (Vyleesi): 1.75 mg at least 45 minutes before sexual activity. No more than 1 dose in 24 hours or 8 doses a month. From community reports, not established: Off-label users often start at 1 mg to gauge nausea. These are the amounts sources reference, not recommendations.

How much water do I mix PT-141 with?

There’s no single right amount, because the water only sets the strength. With 2 mL of bacteriostatic water in a 10 mg vial, the strength is 5 mg/mL, so 1.75 mg is 35 units on a U-100 insulin syringe. More water makes small doses easier to measure. The dose chart above shows other volumes.

What is the half-life of PT-141?

About 2.7 hours, according to the prescribing information. Mean terminal half-life after a single subcutaneous dose, range 1.9 to 4.0 hours.

How should PT-141 be stored?

Not supplied as powder. Vyleesi autoinjectors are stored at or below 25 °C (77 °F), not frozen, protected from light. Single-dose prefilled autoinjector; discard after one use.

Is PT-141 banned in sport?

No. Not named on the 2026 list. As an approved drug (Vyleesi), bremelanotide is outside S0 non-approved substances.

Has PT-141 been studied in people?

Yes. The human studies section lists 3 published studies. The largest, from 2019, included 1,267 people. Desire score rose 0.35 points and distress fell 0.33 points more than placebo (both P<.001); nausea, flushing and headache in 10% or more.

Sources

Vyleesi (bremelanotide) label (DailyMed)

For the protocol details

Vyleesi (bremelanotide) prescribing information (FDA, 2019)

Doses tagged Community come from public dosing guides and user reports, checked against at least two of them. Those sites aren’t named here because many of them sell peptides or earn commissions on them.

By Vial Guide editorsLast reviewed October 5, 2026

How we review