Compare Peptides
Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.
Popular comparisons
A neuropeptide that acts as the master regulator of the reproductive hormone axis. Kisspeptin neurons in the hypothalamus control the release of GnRH (gonadotropin-releasing hormone), which in turn drives LH and FSH production. Increasingly studied for fertility treatment, hypogonadism, and as a diagnostic tool for reproductive disorders. Also being explored for its role in emotional and sexual brain processing.
A synthetic melanocortin receptor agonist derived from Melanotan II. Unlike Melanotan II, PT-141 was developed specifically for sexual dysfunction and received FDA approval in 2019 as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women.
Binds to the KISS1R (GPR54) receptor on GnRH neurons in the hypothalamus, triggering GnRH release. This stimulates the anterior pituitary to release LH and FSH, which drive testosterone production in males and ovulation in females. Kisspeptin is the upstream 'gatekeeper' of the entire HPG axis.
Activates melanocortin receptors (MC3R and MC4R) in the central nervous system, increasing sexual desire through a brain-based mechanism rather than vascular effects. This distinguishes it from PDE5 inhibitors like sildenafil which work peripherally.
- Fertility treatment (investigational)
- Hypogonadism evaluation
- IVF protocols (as GnRH trigger alternative)
- Reproductive endocrinology research
- Libido and sexual function research
- Female sexual dysfunction (FDA-approved indication)
- Male sexual dysfunction (off-label)
- Libido enhancement
- Erectile dysfunction (off-label)
- Injection site discomfort
- Headache and flushing
- Potential for ovarian hyperstimulation in women
- Short half-life requires frequent dosing or infusion
- Limited long-term safety data
- Nausea (most common side effect — ~40% in trials)
- Flushing
- Headache
- Transient blood pressure increase
- Hyperpigmentation with repeated use
- Injection site reactions
Not FDA-approved. Active clinical trials at Imperial College London and other institutions for fertility applications. Being studied as a safer alternative to hCG triggers in IVF (lower risk of ovarian hyperstimulation syndrome). No US-approved formulation exists.
FDA-approved as Vyleesi (bremelanotide injection) in June 2019 for hypoactive sexual desire disorder (HSDD) in premenopausal women. Off-label use for male sexual dysfunction is common through telehealth clinics. Available through compounding pharmacies with prescription.
This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.