Compare Peptides
Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.
Popular comparisons
A synthetic GnRH agonist that paradoxically suppresses gonadotropin release with chronic use. One of the most commercially important peptide drugs, used in prostate cancer, endometriosis, precocious puberty, and fertility treatments.
A synthetic form of the naturally occurring gonadotropin-releasing hormone (GnRH). Used clinically to evaluate pituitary function and increasingly prescribed in peptide therapy to maintain endogenous testosterone production during TRT or peptide cycles. Acts on the pituitary to stimulate LH and FSH release.
Initially stimulates LH and FSH release (flare effect), then downregulates GnRH receptors with continuous exposure, leading to profound suppression of testosterone and estrogen production. This 'chemical castration' effect is therapeutically useful.
Binds to GnRH receptors on gonadotroph cells in the anterior pituitary, triggering pulsatile release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This maintains the HPG axis feedback loop and preserves testicular function, including spermatogenesis.
- Prostate cancer treatment
- Endometriosis
- Uterine fibroids
- Precocious puberty
- Fertility treatments (IVF protocols)
- Maintaining fertility during TRT
- Pituitary function testing
- Hypothalamic amenorrhea treatment
- Post-cycle therapy (PCT)
- Preserving testicular size during hormone therapy
- Hot flashes
- Bone density loss with long-term use
- Mood changes and depression
- Initial testosterone flare (prostate cancer)
- Injection site reactions
- Cardiovascular risk with prolonged use
- Injection site reactions
- Headache and nausea
- Flushing
- Potential for desensitization with continuous (non-pulsatile) use
- Allergic reactions (rare)
FDA-approved as Lupron/Lupron Depot (multiple indications since 1985) and Eligard. One of the highest-revenue peptide drugs historically. Available in 1-month, 3-month, 4-month, and 6-month depot formulations.
FDA-approved as Factrel for diagnostic evaluation of pituitary gonadotroph function. Lutrelef (pulsatile gonadorelin) approved in 2024 for hypothalamic amenorrhea. Widely compounded for off-label use in fertility preservation during TRT.
This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.