Adult: For hormonal management of endometriosis, including pain relief and reduction of endometriotic lesions: As 2 mg/mL nasal spray: 1 spray (200 mcg) into 1 nostril in the morning and 1 spray (200 mcg) into the other nostril in the evening, starting on days 2-4 of the menstrual cycle. Total dose: 400 mcg daily. If regular menstruation persists after 2 months of treatment, may increase to 1 spray into each nostril in the morning and again in the evening (total dose: 800 mcg daily). Max treatment duration: 6 months (only one 6-month course is recommended). Treatment recommendations may vary between countries (refer to local or specific product guidelines).
Nasal Pituitary desensitisation before ovulation induction with gonadotrophins
Adult: For in vitro fertilisation: As 2 mg/mL nasal spray: 1 spray (200 mcg) into each nostril in the morning and 1 spray (200 mcg) into each nostril in the evening, starting either on early follicular phase (day 2) or mid-luteal phase (usually day 21) of the menstrual cycle. Total dose: 800 mcg daily. Continue therapy until pituitary downregulation is achieved, then maintain during gonadotrophin treatment until the administration of chorionic gonadotrophin at follicular maturity. If downregulation does not occur within 12 weeks, discontinue therapy.
Nasal Central precocious puberty
Child: For treatment of gonadotrophin-dependent cases in children of both sexes: As 2 mg/mL nasal spray: 2 sprays (400 mcg) into each nostril in the morning and 2 sprays (400 mcg) into each nostril in the evening. Total dose: 1,600 mcg daily. If suppression is inadequate, may increase to 3 sprays (600 mcg) into alternating nostrils tid (total dose: 1,800 mcg daily). Continue therapy until resumption of puberty is desired.
Contraindications
Undiagnosed abnormal vaginal bleeding. Pregnancy and lactation.
Special Precautions
Patient with major risk factors for reduced bone mass (e.g. strong family history of osteoporosis, antiseizure or corticosteroid treatment, chronic alcohol use), PCOS, history of seizures, cerebrovascular disorders, CNS anomalies or tumours, intercurrent rhinitis, history of psychiatric illness or other comorbidities increasing the risk of depression. Children.
Adverse Reactions
Significant: Ovarian cysts (may occur in the initial 2 months of therapy), ovarian hyperstimulation syndrome; decreased BMD; pseudotumour cerebri (idiopathic intracranial hypertension), seizures, psychiatric events (e.g. depression, irritatability, aggression; rarely, suicidal ideation or attempt), severe cutaneous adverse reactions (e.g. Stevens-Johnson syndrome [SJS], toxic epidermal necrolysis [TEN], drug reaction with eosinophilia and systemic symptoms [DRESS], acute generalised exanthematous pustulosis). Rarely, pituitary apoplexy (characterised by sudden headache, vomiting, visual changes, altered mental status, and sometimes CV collapse). Blood and lymphatic system disorders: Eosinophilia. Endocrine disorders: Estrogen deficiency. General disorders and administration site conditions: Oedema. Immune system disorders: Hypersensitivity reactions (e.g. chest pain, urticaria, pruritus, dyspnoea, rash). Investigations: Decreased or increased weight; decreased WBC count; increased serum triglycerides and total cholesterol. Metabolism and nutrition disorders: Hyperphosphataemia, hypocalcaemia. Musculoskeletal and connective tissue disorders: Myalgia, arthralgia. Nervous system disorders: Paraesthesia. Psychiatric disorders: Insomnia. Reproductive system and breast disorders: Vulvovaginal dryness, vaginal discharge, uterine haemorrhage, breast atrophy, artificial menopause, decreased or increased libido. Respiratory, thoracic and mediastinal disorders: Rhinitis, nasal mucosal irritation. Skin and subcutaneous tissue disorders: Acne vulgaris, hypertrichosis, body odour, seborrhoea, hirsutism, alopecia. Vascular disorders: Hypertension, hypotension, hot flushes.
Monitor BMD (prior to therapy and before retreatment), FSH and LH blood levels, bone age measurement, development or worsening of psychiatric symptoms, menstruation, vaginal bleeding/spotting.
Drug Interactions
May enhance the effect of corifollitropin alfa.
Lab Interference
May give misleading result in the diagnostic test for pituitary gonadotrophic and gonadal functions up to 4-8 weeks after treatment discontinuation.
Action
Description: Mechanism of Action: Nafarelin is a gonadorelin analogue. It produces an initial phase of stimulation followed by downregulation of gonadotrophin-releasing hormone receptors, thus reducing the release of FSH and LH, leading to inhibition of androgen and estrogen production. Pharmacokinetics: Absorption: Rapidly absorbed intranasally. Bioavailability: Approx 3%. Time to peak plasma concentration: Within 20 minutes. Distribution: Plasma protein binding: Approx 80%, mainly to albumin. Metabolism: Metabolised by peptidases to form metabolites. Excretion: Via urine (44-55%, approx 3% as unchanged drug); faeces (19-44%). Elimination half-life: Approx 3 hours.
Chemical Structure
Nafarelin Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 25077405, Nafarelin. https://pubchem.ncbi.nlm.nih.gov/compound/Nafarelin. Accessed Feb. 25, 2026.
Storage
Store below 25°C. Protect from light. Do not freeze.
H01CA02 - nafarelin ; Belongs to the class of gonadotropin-releasing hormones. Used in hypothalamic hormone preparations.
References
Brayfield A, Cadart C (eds). Nafarelin Acetate. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 11/02/2026.Joint Formulary Committee. Nafarelin. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 11/02/2026.Nafarelin Acetate. UpToDate Lexidrug, AHFS DI (Adult and Pediatric) Online. American Society of Health-System Pharmacists, Inc. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 11/02/2026.Nafarelin. UpToDate Lexidrug, Lexi-Drugs Multinational Online. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 11/02/2026.Synarel 2 mg/mL Nasal Spray (Pfizer Limited). MHRA. https://products.mhra.gov.uk. Accessed 16/02/2026.Synarel Spray, Metered (Pfizer Laboratories Div Pfizer Inc). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 11/02/2026.
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