Page data last changed: . Chemistry registry snapshot: . Registry refreshes and identity assessments are separate from scientific content review.
A GnRH decapeptide unusual for being delivered as a nasal spray.
Also known as: Synarel
Part of the Foundational & therapeutic peptides cluster
Overview
Nafarelin is a synthetic decapeptide GnRH agonist administered intranasally. Continuous receptor activation desensitizes the pituitary and suppresses luteinizing and follicle-stimulating hormone, and it is an approved therapeutic for endometriosis and central precocious puberty. This page is educational and not medical advice.
Source & context
Biological / chemical source: Synthetic decapeptide analog of GnRH
Primary research or clinical context: Approved for endometriosis and central precocious puberty (intranasal)
Intranasal delivery
Nafarelin's nasal-spray formulation is notable because most GnRH analogs require injection or implant. Nasal absorption offers a needle-free route, illustrating how peptide lipophilicity and potency can be tuned to enable mucosal delivery.
Hormone suppression
Repeated dosing collapses pituitary gonadotropin output, lowering estrogen and reducing endometriotic tissue activity or halting premature pubertal progression. Nafarelin is a well-studied member of the GnRH-analog class alongside leuprolide and goserelin.
Sequence
One-letter sequence commonly cited for Nafarelin (educational; isoforms and modifications may differ):
XHWSYXLRPG
X = non-canonical residue (C terminal amidation; N-terminal pyroglutamate; 3-(2-naphthyl)-D-alanine (D-3-naphthylalanine; D-Nal) substitution at residue 6). X marks a non-canonical residue — see the structure block below. (Plotted as alanine on the wheel.)
Residues plotted ~100° apart around an α-helix — clustering of one color reveals an amphipathic face.
Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.
- Molecular form
- Nafarelin (source record; form not independently established)
- Species
- Not established by this molecular identity audit
- Termini (N / C)
- Not specified / Not specified
Average reference mass
Reference policy updated: 2026-10-05
- IUPHAR/BPS source snapshot · 2026-10-01
- PubChem molecular record · 2026-10-01
- Molecular formula
- C66H83N17O13
- Average reference mass
- ≈ 1,322.5
- Status
- Approved medicine in at least one jurisdiction (IUPHAR record)
C terminal amidation; N-terminal pyroglutamate; 3-(2-naphthyl)-D-alanine (D-3-naphthylalanine; D-Nal) substitution at residue 6
- PubChem CID: 25077405
- IUPHAR ligand: 3902
- ChEMBL: CHEMBL1201309
- DrugBank: DB00666
- CAS RN: 76932-56-4
- UNII: 1X0094V6JV
Chemistry values: IUPHAR/BPS Guide to Pharmacology, PubChem · fetched 2026-10-01.
Clinical development snapshot
ClinicalTrials.gov lists 12 registered studies with “Nafarelin” as an intervention (snapshot 2026-09-06). A registry footprint is not evidence of efficacy or approval.
| NCT | Title | Phase | Status | Updated |
|---|---|---|---|---|
| NCT06763926 | Intranasal Nafarelin For Triggering Oocyte Maturation | Phase 4 | not yet recruiting | 2026-09-03 |
| NCT07620067 | GnRH for Luteal Support - Mechanism of Action | — | recruiting | 2026-06-02 |
| NCT06150703 | Luteal Phase Support With GnRH Agonist After GnRH Agonist Triggering in IVF/ICSI Cycles | Phase 3 | recruiting | 2025-08-24 |
| NCT06870266 | Comparison of Pregnancy Rates in Modified Natural Frozen Embryo Transfer (FET) Cycle After Luteal Support with | Early phase 1 | not yet recruiting | 2025-03-11 |
| NCT04850261 | Injection Free IVF | Phase 2 | withdrawn | 2024-10-30 |
| NCT05801705 | Comparative Evaluation of Efficacy and Safety of Toremifene, Tamoxifen, and Aromatase Inhibitor Plus Ovarian F | — | unknown | 2023-05-18 |
Nafarelin — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Nafarelin (source record; form not independently established)Average reference mass: 1,322.5 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
FAQ about Nafarelin
What is Nafarelin?+
Nafarelin is a synthetic decapeptide GnRH agonist administered intranasally. Continuous receptor activation desensitizes the pituitary and suppresses luteinizing and follicle-stimulating hormone, and it is an approved therapeutic for endometriosis and central precocious puberty. This page is educational and not medical advice.
What Canadian product status is recorded for Nafarelin?+
Canadian product status for Nafarelin has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the typical length of Nafarelin?+
Nafarelin is commonly described as approximately 10 amino acids (GnRH agonist).
Related peptides
References & further reading
- 1.Bergqvist et al. (1997). A double-blind randomized study of the treatment of endometriosis with nafarelin or nafarelin plus norethisterone. Gynecol Endocrinol
- 2.Palatyński et al. (2001). [Nafarelin acetate (Synarel) and thermocoagulation in the treatment of endometriosis]. Ginekol Pol
- 3.Wong et al. (2001). Efficacy of nafarelin in assisted reproductive technology: a meta-analysis. Hum Reprod Update
- 4.Adamson et al. (1997). Therapeutic efficacy and bone mineral density response during and following a three-month re-treatment of endometriosis with nafarelin (Synarel). Am J Obstet Gynecol
- 5.Rosenfield et al. (1986). The rapid ovarian secretory response to pituitary stimulation by the gonadotropin-releasing hormone agonist nafarelin in sexual precocity. J Clin Endocrinol Metab
- 6.Chrisp et al. (1990). Nafarelin. A review of its pharmacodynamic and pharmacokinetic properties, and clinical potential in sex hormone-related conditions. Drugs
- 7.Eldred et al. (1992). A randomized double blind placebo controlled trial of the effects on bone metabolism of the combination of nafarelin acetate and norethisterone. Clin Endocrinol (Oxf)
- 8.Audebert et al. (1998). Pre or post-operative medical treatment with nafarelin in stage III-IV endometriosis: a French multicenter study. Eur J Obstet Gynecol Reprod Biol
- 9.PubChem — compound summary for Nafarelin (CID 25077405)
- 10.Wikipedia — Nafarelin