Buserelin is a synthetic GnRH agonist nonapeptide analog (MW ~1299.5 g/mol) with a D-Ser(tBu) substitution at position 6 and an NHEt modification at position 10. It is approved in the European Union, Canada, Australia, and other countries for the treatment of advanced prostate cancer, endometriosis, and as part of IVF protocols, but it is not approved by the FDA in the United States. Buserelin is available as a nasal spray (Suprecur), subcutaneous injection, and depot implant (Suprefact Depot), providing multiple route options for different clinical scenarios.
Category: Reproductive / Hormonal. Evidence rating: A (strong human clinical data).
Clinical status: Approved in EU, Canada, Australia, and other markets for prostate cancer, endometriosis, and IVF protocols. Not FDA-approved in the United States.
Buserelin is a GnRH agonist approximately 20-40 times more potent than native GnRH. Like other GnRH agonists, it operates through the "flare then suppression" mechanism. Initial administration causes transient stimulation of pituitary gonadotrophs, resulting in an LH and FSH surge with temporary…
Safety considerations: Hot flashes (common, similar frequency to other GnRH agonists); Decreased libido and sexual dysfunction; Headache and mood changes.
Reviewed by the PeptideAtlas Editorial Team. Last reviewed: 2026-08-12.
Related peptides: Kisspeptin, Gonadorelin, Oxytocin.
Compare: Buserelin vs Kisspeptin, Buserelin vs Gonadorelin, Buserelin vs Oxytocin.
Buserelin was never submitted for or received FDA approval in the United States. The US market has multiple alternative GnRH agonists (leuprolide, goserelin, triptorelin, histrelin, nafarelin) that fill the same clinical niches. Buserelin remains widely used in Europe, Canada, and Australia.
Buserelin is available as a nasal spray (Suprecur), subcutaneous injection, and depot implant (Suprefact Depot). For prostate cancer, the nasal spray is typically given as 400 mcg three times daily. For IVF protocols, either the nasal spray or subcutaneous injection may be used for pituitary downregulation.
Buserelin has comparable efficacy to leuprolide, goserelin, and triptorelin for testosterone suppression and endometriosis treatment. Its main distinguishing features are the availability of a nasal spray formulation (shared only with nafarelin among GnRH agonists) and its long track record in European clinical practice.