Nafarelin
Nafarelin is an FDA-approved GnRH receptor agonist. Nafarelin is a GnRH agonist whose D-naphthylalanine substitution at position 6 increases receptor affinity and resistance to degradation, giving sufficient bioavailability for nasal administration. Continuous receptor stimulation downregulates pituitary GnRH receptors after an initial gonadotropin rise, producing reversible suppression of ovarian or testicular steroid production.
For research use only.
Key Facts
- CAS
- 76932-56-4
- Molecular Weight (MW)
- 1322.5 g/mol
- Half-life
- —
- FDA status
- Approved
- Administration Route
- intranasal
- Frequency
- —
- Last updated
- Aug 30, 2026
- Reviewed
- Aug 30, 2026
Research summary
Intranasally administered GnRH receptor agonist approved for endometriosis and for central precocious puberty. One of the few peptide drugs delivered routinely by nasal spray.
Peptide Library's Nafarelin profile summarises 5 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Protocol
- Dosage Range
- —
- Frequency
- —
- Cycle
- —
- Administration Route
- intranasal
- Reconstitution Guide
- —
Not yet checked against primary sources
These figures are compiled from earlier reference material. They have not been verified against FDA labelling, registered trials or published literature, no citation is attached to them, and none of them is a recommended dose. Nafarelin is queued for dosage evidence review.
Compare reported doses across the whole librarySequence & molecular data
| Molecular formula | C66H83N17O13 |
|---|---|
| Molecular weight | 1322.5 g/mol |
| CAS number | 76932-56-4 |
| PubChem CID | 25077405 |
| FDA UNII | 1X0094V6JV |
| DrugBank | DB00666 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
Nafarelin is a GnRH agonist whose D-naphthylalanine substitution at position 6 increases receptor affinity and resistance to degradation, giving sufficient bioavailability for nasal administration. Continuous receptor stimulation downregulates pituitary GnRH receptors after an initial gonadotropin rise, producing reversible suppression of ovarian or testicular steroid production.
Studies
- Prospective randomized comparison of ovarian blockade with nafarelin versus leuprolide during ovarian stimulation with recombinant FSH in an ICSI program
- A double-blind randomized study of the treatment of endometriosis with nafarelin or nafarelin plus norethisterone
- [Nafarelin acetate (Synarel) and thermocoagulation in the treatment of endometriosis]
- Treatment with nafarelin for endometriosis in young women. Efficacy, safety and lipid metabolism. Niigata Nafarelin Study Group
- Retreatment with nafarelin for recurrent endometriosis symptoms: efficacy, safety, and bone mineral density
Regulatory & research status
Nafarelin is an FDA-approved product for specific labelled indications. Approval does not extend to the research contexts described on this page, and approved products are prescription medicines.
| FDA status | Approved |
|---|---|
| Research status | Approved product (see FDA status) |
| Availability | Prescription-Only |
| WADA (sport) | Unknown / Not Listed |
| Library classification | FDA-Approved |
Benefits
—
Potential Side Effects
No side effects listed yet for this entry.
Storage & stability
Lyophilized (freeze-dried) peptide powder is far more stable than the reconstituted solution. Keep sealed vials cold, dry and away from light; long-term storage is typically frozen, with short-term refrigeration for vials in use.
Once reconstituted in bacteriostatic water, keep the solution refrigerated, avoid repeated freeze–thaw cycles and agitation, and label the vial with the reconstitution date and concentration. Discard any solution that turns cloudy or shows particulates.
Degradation rates differ by sequence: peptides containing methionine, cysteine, asparagine or glutamine are more prone to oxidation and deamidation, so shelf life after reconstitution is compound-specific rather than universal.
Read the full guide: how to store peptides before and after reconstitution →
Source: Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. (PMID 20143256). General guidance for research handling; not product-specific instructions.
Nafarelin: frequently asked questions
What is Nafarelin?
Intranasally administered GnRH receptor agonist approved for endometriosis and for central precocious puberty. One of the few peptide drugs delivered routinely by nasal spray.
How does Nafarelin work?
Nafarelin is a GnRH agonist whose D-naphthylalanine substitution at position 6 increases receptor affinity and resistance to degradation, giving sufficient bioavailability for nasal administration. Continuous receptor stimulation downregulates pituitary GnRH receptors after an initial gonadotropin rise, producing reversible suppression of ovarian or testicular steroid production.
Is Nafarelin FDA approved?
Yes. Nafarelin is approved by the FDA, and approved products are prescription medicines. Approval is always for specific indications studied in clinical trials, so an approved status does not mean the compound is approved for every use it is discussed for. Research-chemical material sold under the same name is not the approved product.
What peptides are similar to Nafarelin?
Compounds most often compared with Nafarelin include Leuprolide, Goserelin, Triptorelin and Histrelin. They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ.
References
- Prospective randomized comparison of ovarian blockade with nafarelin versus leuprolide during ovarian stimulation with recombinant FSH in an ICSI program — J Assist Reprod Genet, 2001External reference
- A double-blind randomized study of the treatment of endometriosis with nafarelin or nafarelin plus norethisterone — Gynecol Endocrinol, 1997External reference
- [Nafarelin acetate (Synarel) and thermocoagulation in the treatment of endometriosis] — Ginekol Pol, 2001External reference
- Treatment with nafarelin for endometriosis in young women. Efficacy, safety and lipid metabolism. Niigata Nafarelin Study Group — J Reprod Med, 2000External reference
- Retreatment with nafarelin for recurrent endometriosis symptoms: efficacy, safety, and bone mineral density — Fertil Steril, 1997External reference
Related research, comparisons & guides
Related peptides
Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Aug 30, 2026 · Version 1
This Nafarelin profile is compiled from published literature (5 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
Track Nafarelin research, inventory and reconstitution in the free Peptide Library app. Get the app for iOS or Android →