How much BAC water do I add to a PT-141 vial?

PT-141 is commonly supplied in 10 mg vials. 1–2 mL of BAC water is typical. Use the calculator above to find the exact draw volume for your target dose.

What concentration does 1 mL give in a 10 mg PT-141 vial?

10 mg/mL (10,000 mcg/mL). A 1000 mcg dose equals 0.1 mL, which is 10 units on a U-100 insulin syringe.

How is PT-141 different from Melanotan II?

PT-141 is a derivative of Melanotan II with a modified structure giving it different receptor selectivity. Both have dedicated calculators on PepperCalc.

PT-141 Dosing Calculator & Protocol

What is PT-141?

PT-141 was developed from Melanotan II by removing the melanocyte-stimulating portion, creating a compound selective for MC3R and MC4R without the strong MC1R (tanning) and MC5R effects. It received FDA approval as Vyleesi® in 2019, becoming the first non-hormonal FDA-approved treatment for HSDD — a condition affecting approximately 10% of premenopausal women.

Unlike PDE5 inhibitors (sildenafil, tadalafil) which work peripherally through vascular mechanisms, PT-141 acts centrally through hypothalamic MC4R pathways to increase sexual desire and arousal. This makes it effective in both men and women regardless of vascular health. Off-label research use in men for erectile dysfunction and low libido has also been extensively reported.

🧠

Central MC4R Activation

Activates hypothalamic MC4R signaling pathways that regulate sexual arousal and desire — central mechanism distinct from peripheral vascular agents.

❤️

Libido Enhancement

Increases sexual desire and motivation through central melanocortin pathways in hypothalamic nuclei (MPOA, PVN) that regulate sexual behavior.

⚡

Erectogenic Effect

MC4R activation in the spinal cord and hypothalamus promotes penile erection through melanocortinergic pathways — studied in men with organic ED.

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Non-Vascular Mechanism

Works independently of nitric oxide/vascular mechanisms — effective even when PDE5 inhibitors fail or are contraindicated due to cardiovascular issues.

Dosing Schedule

Parameters documented in published preclinical and clinical research.

⚠️ Research use only. The following documents parameters from published preclinical and clinical research. Not medical advice. Not for human consumption. Consult a licensed healthcare professional before any use.

Phase	Dose	Frequency	Duration	Notes
FDA-approved (female HSDD)	1.75 mg SubQ	45 min before sexual activity	Max 1× / 24h, max 8× / month	Vyleesi-approved dose. Abdomen or thigh SubQ. No more than 8 doses per month per FDA guidance.
Male research	0.5–2 mg	45–60 min before activity	As needed, max 8× / month	Off-label male research dose. Start at 0.5 mg to assess nausea tolerance.
Intranasal	1–2 mg	45 min before	As needed	Earlier nasal spray formulations — lower and more variable bioavailability than SubQ.
Titration	Start 0.5 mg → up to 1.75 mg	Per response	Gradual	Titrate to effective dose while minimizing nausea side effect. 1.75 mg is the FDA ceiling.

Phase

Dose

Frequency

Duration

Notes

FDA-approved (female HSDD)

1.75 mg SubQ

45 min before sexual activity

Max 1× / 24h, max 8× / month

Vyleesi-approved dose. Abdomen or thigh SubQ. No more than 8 doses per month per FDA guidance.

Male research

0.5–2 mg

45–60 min before activity

As needed, max 8× / month

Off-label male research dose. Start at 0.5 mg to assess nausea tolerance.

Intranasal

1–2 mg

45 min before

As needed

Earlier nasal spray formulations — lower and more variable bioavailability than SubQ.

Titration

Start 0.5 mg → up to 1.75 mg

Per response

Gradual

Titrate to effective dose while minimizing nausea side effect. 1.75 mg is the FDA ceiling.

Safety & Side Effects

✓ Generally Well Tolerated

FDA-approved (Vyleesi) for female HSDD — highest regulatory status

Central mechanism — effective regardless of vascular health

Non-hormonal — no effect on estrogen/testosterone balance

As-needed dosing — no daily maintenance required

⚠ Potential Concerns

Nausea in 40% of subjects — primary limiting side effect

Transient hypertension immediately post-injection — avoid in cardiovascular disease

Facial flushing and hyperpigmentation with repeated use

Contraindicated with cardiovascular disease (transient BP increase)

⚠️

Research use onlyThis page is an educational reference. None of this constitutes medical advice. Consult a qualified professional before any use. All compounds are for research purposes only.

Academic References

[1]

Diamond LE, et al. (2004). A double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141. J Sex Med. 1(1):10–8. PubMed ↗

[2]

Kingsberg SA, et al. (2019). Bremelanotide for the treatment of hypoactive sexual desire disorder. Obstet Gynecol. 134(5):899–908. PubMed ↗

[3]

Safarinejad MR. (2008). Evaluation of the safety and efficacy of bremelanotide, a melanocortin receptor agonist, in female subjects with arousal disorder. J Sex Med. 5(4):887–97. PubMed ↗

[4]

Clayton AH, et al. (2016). Bremelanotide for female sexual dysfunctions in premenopausal women. Obstet Gynecol. 128(6):1239–50. PubMed ↗

PT-141: bremelanotide — FDA-approved desire peptide.

PT-141
Dosage Protocol

What is PT-141?

Dosing Schedule

Safety & Side Effects

Academic References

PT-141: bremelanotide — FDA-approved desire peptide.

PT-141Dosage Protocol

What is PT-141?

Dosing Schedule

Safety & Side Effects

Academic References

PT-141
Dosage Protocol