Compare Peptides
Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.
Popular comparisons
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.
A selective growth hormone secretagogue that stimulates GH release with minimal effects on cortisol and prolactin. Considered one of the 'cleanest' GH-releasing peptides due to its selectivity.
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.
Binds to ghrelin receptors (GHS-R) in the pituitary gland, triggering pulsatile growth hormone release. Unlike other GH secretagogues, it does not significantly increase cortisol, ACTH, or prolactin levels.
- Maintaining fertility during TRT
- Pituitary function testing
- Hypothalamic amenorrhea treatment
- Post-cycle therapy (PCT)
- Preserving testicular size during hormone therapy
- Growth hormone optimization
- Improved sleep quality
- Fat loss
- Muscle recovery and growth
- Anti-aging protocols
- Injection site reactions
- Headache and nausea
- Flushing
- Potential for desensitization with continuous (non-pulsatile) use
- Allergic reactions (rare)
- Headaches
- Water retention
- Tingling sensations
- Limited long-term human data
- May affect blood sugar
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.
Reclassified to Category 1 in February 2026 as part of the HHS announcement restoring compounding access. Not affected by the April 15, 2026 Category 2 removal action. Available through licensed 503A compounding pharmacies with a physician prescription.
- Ipamorelin, a new growth-hormone-releasing peptide
1998 · PubMed
This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.