Approved & therapeutic
Nafarelin
Synarel
Nafarelin is a GnRH agonist given as a nasal spray, approved for endometriosis and for central precocious puberty. The intranasal route distinguishes it from the injectable and implanted agonists.
Also known as: nafarelin acetate
- Status
- Nafarelin is approved by the U.S. FDA and has official prescribing information.
- Evidence
- Approved labeling. Official prescribing information exists, based on clinical trials in people.
- Half-life
- Approximately 3 hours after intranasal administration.
- How it's taken
- Intranasal spray, dosed twice daily
- Mechanism
- Reproductive axis (GnRH / kisspeptin / oxytocin)
- Pathways
- GnRH, Estrogen
How Nafarelin works
Like other GnRH agonists, continuous exposure first stimulates and then desensitises pituitary GnRH receptors, suppressing LH and FSH and therefore estradiol or testosterone. Nafarelin is substantially more potent than native GnRH, which is what makes nasal absorption sufficient.
What research has looked at
- Suppresses estradiol in endometriosis, reducing lesion-associated pain over a treatment course typically limited to six months.
- Halts pubertal progression in central precocious puberty.
- Nasal administration avoids injection entirely, which matters particularly in the paediatric indication.
Evidence level: Approved labeling. Official prescribing information exists, based on clinical trials in people. These are areas studied or reported, not promised effects.
Reported side effects and risks
- Hypoestrogenic effects: hot flashes, vaginal dryness, decreased libido, headache and mood changes.
- Loss of bone mineral density, which is why the endometriosis course is duration-limited and generally not repeated.
- Nasal irritation, and rhinitis or nasal decongestant use can alter absorption — a route-specific reliability problem.
- The initial gonadotropin surge causes a transient symptom flare in the first weeks.
- Contraindicated in pregnancy and in undiagnosed abnormal vaginal bleeding.
Sources
- FDA approved-drug listing for nafarelin · U.S. Food & Drug Administration
- DailyMed prescribing information for nafarelin · NIH · DailyMed
- PubMed research on nafarelin endometriosis intranasal · NIH · National Library of Medicine
- DrugBank record for nafarelin · DrugBank
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Related compounds
Nafarelin FAQ
What is Nafarelin?
Nafarelin is a GnRH agonist given as a nasal spray, approved for endometriosis and for central precocious puberty. The intranasal route distinguishes it from the injectable and implanted agonists.
How does Nafarelin work?
Like other GnRH agonists, continuous exposure first stimulates and then desensitises pituitary GnRH receptors, suppressing LH and FSH and therefore estradiol or testosterone. Nafarelin is substantially more potent than native GnRH, which is what makes nasal absorption sufficient.
Is Nafarelin FDA approved?
Yes. Nafarelin is approved by the U.S. FDA and has official prescribing information. Evidence level: approved labeling. Official prescribing information exists, based on clinical trials in people.
What is the half-life of Nafarelin?
Reported half-life: Approximately 3 hours after intranasal administration.
How is Nafarelin taken?
Intranasal spray, dosed twice daily.
What side effects have been reported with Nafarelin?
Reported in the sources: Hypoestrogenic effects: hot flashes, vaginal dryness, decreased libido, headache and mood changes; Loss of bone mineral density, which is why the endometriosis course is duration-limited and generally not repeated; Nasal irritation, and rhinitis or nasal decongestant use can alter absorption — a route-specific reliability problem; The initial gonadotropin surge causes a transient symptom flare in the first weeks; Contraindicated in pregnancy and in undiagnosed abnormal vaginal bleeding.
Educational summary compiled from the sources listed above. Not medical advice. Peptide Vault does not sell, source or recommend any compound. Talk to a qualified clinician before starting or changing anything.