Parents of a child showing early signs of puberty, or patients exploring fertility treatment options, may come across nafarelin as part of a care plan. This peptide has an established place in reproductive endocrinology, with decades of clinical use behind its approved formulation.
Key takeaways
- Nafarelin is FDA-approved under the brand name Synarel for central precocious puberty (CPP).
- The label does not carry a boxed warning.
- Thirteen clinical trials involving nafarelin are registered, spanning fertility and reproductive research.
- FAERS reports linked to nafarelin are dominated by ovarian hyperstimulation syndrome, with smaller numbers of respiratory, gastrointestinal, and general symptoms.
- Its chemical identity is catalogued under PubChem CID 25077405.
What Nafarelin Is
Nafarelin is a synthetic peptide belonging to the class of compounds used in reproductive hormone therapy. The approved product, Synarel, is administered to modify hormone signaling involved in puberty and reproductive cycling. Its structure is that of a modified peptide analog, reflected in its molecular formula of roughly 66 carbons and 17 nitrogens.
What Nafarelin Is Approved For
Synarel is indicated for the treatment of central precocious puberty (CPP), also called gonadotropin-dependent precocious puberty, in both girls and boys. This diagnosis is typically suspected when secondary sexual characteristics appear unusually early, before age 8 in girls and age 9 in boys. Confirmation involves hormone level testing, a gonadotropin-releasing hormone stimulation test, and often pelvic ultrasound imaging to assess uterine and ovarian development. The label notes that Synarel has additional labeling for endometriosis as well. No boxed warning is present on the label.
What the Evidence Shows
Thirteen clinical trials have been registered involving nafarelin. Recent studies include a trial examining intranasal nafarelin for triggering oocyte maturation, currently not yet recruiting, and a completed study protocol designed to minimize injections and blood draws for women undergoing in vitro fertilization. Another registered trial compares pregnancy rates using GnRH agonist luteal support against progesterone in frozen embryo transfer cycles.
Reported Side Effects
Reports submitted to the FDA Adverse Event Reporting System reflect voluntary reports, not confirmed incidence or direct causation. The most frequently reported reaction associated with nafarelin is ovarian hyperstimulation syndrome, with 48 reports. Respiratory and abdominal symptoms follow, including dyspnoea (19 reports) and ascites (18 reports). Smaller numbers of reports describe condition aggravation, diarrhoea, headache, and nausea, each with 13 reports, alongside a similar count of reports flagged as off label use.