Reproductive · FDA Approved
Nafarelin (Synarel)
FDA-approved
01 · Overview
Nafarelin is a synthetic decapeptide analogue of gonadotropin-releasing hormone with substitutions that enhance receptor affinity and metabolic stability. Chronic administration downregulates pituitary GnRH receptors and suppresses gonadotropin secretion, producing a hypoestrogenic state.
This mechanism is used therapeutically where ovarian or gonadal suppression is wanted, including endometriosis and central precocious puberty. The intranasal product Synarel, approved under NDA 019886, remains listed as a prescription product in the FDA drug approval database.
02 · Research summary & key findings
FDA approval of nafarelin was granted in February 1990 according to the FDA drug approval database. In a randomized, double-blind, double-dummy European trial of 307 women with laparoscopically confirmed endometriosis, intranasal nafarelin and oral danazol were equally effective at reducing endometriotic lesions and symptoms over six months and at limiting symptom return through 12 months of follow-up; hot flushes were more common with nafarelin, while weight gain and liver enzyme rises were greater with danazol (PMID 1531464). In girls with idiopathic central precocious puberty and an impaired height prognosis, nafarelin suppressed the pituitary-gonadal axis and modestly improved predicted adult height over two years in a small prospective study (PMID 2144020). Longer-acting GnRH analogues have since become more commonly used.
03 · Regulatory status
Nafarelin (Synarel) has received FDA approval and is available for clinical use under appropriate medical supervision. Consult a qualified healthcare provider for prescribing information.
Nafarelin (Synarel) is an FDA-approved medicine prescribed for the conditions on its label. It is not part of our intake, so we do not propose protocols for it. If you think it may be relevant to you, talk to your own doctor. How to ask your doctor.
Looking for a lawful, clinician-prescribed option for hormone optimization?
Nafarelin (Synarel) is prescribed for the conditions on its label, and it is not part of our intake. If you are working on hormone optimization, a licensed clinician can tell you at a free consultation whether an FDA-approved or lawfully compounded treatment fits you, or whether nothing does.
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04 · Administration routes
- Intranasal
References
- [1]Nafarelin for endometriosis: a large-scale, danazol-controlled trial of efficacy and safety, with 1-year follow-up. The Nafarelin European Endometriosis Trial Group (NEET) Fertil Steril, 1992. PMID 1531464
- [2]Preserving adult height potential in girls with idiopathic true precocious puberty J Pediatr, 1990. PMID 2144020
Primary literature
- PubMed: "Nafarelin"
Peer-reviewed literature indexed by the National Library of Medicine.
- ClinicalTrials.gov: "Nafarelin"
Registered interventional and observational studies, including status and phase.
- PubChem: "Nafarelin"
Chemical structure, molecular properties, and bioactivity data.
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