PT-141 (Bremelanotide): Peptide for Sexual Function in Research

EXOMA Scientific Team · Publicado el 13 de abril de 2026 · Actualizado el 17 de agosto de 2026

PT-141 (Bremelanotide): mechanism of action via MC4R, clinical evidence in sexual dysfunction, comparison with PDE5 inhibitors and pharmacological profile.

Introduction to PT-141

PT-141, known as Bremelanotide, is a cyclic heptapeptide derived from Melanotan II. Unlike its precursor, it was developed specifically for its action on the melanocortin 4 receptor (MC4R) in the central nervous system.

General Information

• Generic name: Bremelanotide
• FDA approval: June 2019
• Indication: Hypoactive sexual desire disorder (HSDD) in premenopausal women
• Structure: Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-OH

Mechanism of Action

PT-141 acts through a mechanism fundamentally different from PDE5 inhibitors (sildenafil, tadalafil):

Central Pathway (PT-141)

1. MC4R binding: Agonist del receptor de melanocortina 4 en el hipotálamo
2. Activation of POMC neurons: En el núcleo arcuato hipotalámico
3. Dopaminergic modulation: Aumento de señalización dopaminérgica en áreas de recompensa
4. Central effect: Acts at the level of desire and arousal, not on peripheral blood flow

Peripheral Pathway (PDE5 inhibitors)

• Act on the NO/cGMP pathway in vascular tissue
• Local vasodilatory effect
• They do not modulate desire or central arousal

Comparison of Mechanisms

Clinical Evidence

RECONNECT Studies (Phase III)

Two pivotal randomized, double-blind studies:

• Total N: 1,247 premenopausal women with HSDD
• Duration: 24 weeks
• Dose: 1.75 mg SC on demand
• Results:
• Significant increase in sexual desire (FSFI scale)
• Reduction of distress associated with HSDD (FSDS-DAO scale)
• Onset of effect: ~45 minutes post-injection
• Duration of effect: ~12-24 hours

Studies in Male Populations

Phase II studies in erectile dysfunction:

• Demonstrated efficacy in patients who did not respond to sildenafil
• Mechanism complementary to that of PDE5 inhibitors
• Promising results in psychogenic erectile dysfunction

MC4R pharmacology

The MC4R receptor plays a central role in multiple functions:

• Sexual behavior: Modulation of hypothalamic circuits of sexual motivation
• Appetite: Regulation of food intake (anorexic effect)
• Energy homeostasis: Control of energy expenditure
• Blood pressure: Cardiovascular sympathetic modulation

Neural Circuit

MC4R signaling in sexual function involves:

1. Neuronas MC4R+ en el área preóptica medial (mPOA)
2. Proyecciones al área tegmental ventral (VTA)
3. Liberación de dopamina en el núcleo accumbens
4. Activación de circuitos de motivación/recompensa sexual

Pharmacokinetics

• SC absorption: Bioavailability ~100%
• Tmax: ~1 hour
• Half-life: 2.7 hours
• Metabolism: Peptide hydrolysis
• Duration of effect: Up to 24 hours (beyond the plasma half-life)

Related Peptides

Oxytocin

Oxytocin complements the action of PT-141:

• Modulation of social bonding and prosocial behavior
• Effect on the contraction of uterine smooth muscle
• Role in the orgasmic response

Kisspeptin

Kisspeptin acts upstream in the reproductive axis:

• Regulation of GnRH in hypothalamic neurons
• Modulation of LH and FSH
• Role in puberty and fertility
• Research as a modulator of sexual attraction

Safety Profile

Adverse effects reported in clinical trials:

• Nausea (40% - most common effect)
• Facial flushing (20%)
• Headache (11%)
• Injection site reaction (5%)
• Transient hyperpigmentation with repeated use

Warnings: Contraindicated in uncontrolled hypertension. It can cause a transient increase in blood pressure.

Conclusion

PT-141 (Bremelanotide) represents a unique paradigm in the pharmacology of sexual function by acting centrally on MC4R rather than peripherally on blood flow. Its FDA approval in 2019 validated the concept of melanocortinergic modulation of sexual desire, opening new avenues of research in neuroscience and endocrinology.

Available at Exoma Peptides with certified COA.

References

Material for research use only. The following primary sources support the scientific claims of this article:

1. Kingsberg SA, Clayton AH, Portman D, et al. Bremelanotide for the treatment of hypoactive sexual desire disorder: two randomized phase 3 trials (RECONNECT). Obstet Gynecol. 2019;134(5):899-908. PMID 31599840. (statistically significant improvement but of modest magnitude vs placebo)

Products available at EXOMA

• PT-141 (Bremelanotide)