Peptide LibraryNafarelin dosage in published studies and labels
These are the doses used for Nafarelin in FDA labelling and published clinical studies, reported as each source states them, one row per regimen. They describe what was studied or approved for a specific population. They are not a recommendation, and none of them is a dose for any individual.
Research and educational reference only. This is not medical advice, and no figure on this page is a dosing recommendation.
Last checked against primary sources:
Studied regimens and sources
Nafarelin has FDA-approved human dosages as SYNAREL nasal spray, which delivers 200 mcg per spray. For central precocious puberty in children the label dose is 1600 mcg a day (8 sprays), raised to 1800 mcg a day if suppression is not adequate. For endometriosis in women aged 18 and over it is 400 mcg a day (one spray morning and evening), raised to 800 mcg a day if menstruation continues after 2 months, for 6 months.
| Human dosing established | Yes |
|---|---|
| Route | Intranasal |
| Frequency | Two or three times daily by indication |
| Duration studied | Until puberty is wanted (central precocious puberty); 6 months (endometriosis) |
| Titration | The label allows one step up for each indication if suppression is not adequate. |
| Evidence level | FDA Approved |
| Last reviewed | 2026-11-07 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| FDA label — SYNAREL, central precocious pubertyFDA-approved label · FDA prescribing information | Children of both sexes with central precocious puberty | 1600 mcg a day: 2 sprays (400 mcg) into each nostril in the morning and evening. 1800 mcg a day if suppression is not adequate: 3 sprays (600 mcg) into alternating nostrils three times a day | Intranasal | Twice daily (1600 mcg) or three times daily (1800 mcg) | Until resumption of puberty is desired | Suppression of pituitary-gonadal activity | SYNAREL (nafarelin acetate) nasal solution — FDA prescribing information (Pfizer), DailyMed |
| FDA label — SYNAREL, endometriosisFDA-approved label · FDA prescribing information | Women aged 18 and over with endometriosis | 400 mcg a day: one 200 mcg spray into one nostril in the morning and the other nostril in the evening; 800 mcg a day if regular menstruation continues after 2 months | Intranasal | Twice daily | 6 months, started between days 2 and 4 of the menstrual cycle | Pain relief and reduction of endometriotic lesions | SYNAREL (nafarelin acetate) nasal solution — FDA prescribing information (Pfizer), DailyMed |
Where sources disagree
- The two indications use very different amounts: 1600–1800 mcg a day in central precocious puberty against 400–800 mcg a day in endometriosis.
- For endometriosis the label says retreatment cannot be recommended because safety data are not available, and that bone density should be assessed before any retreatment.
- The label advises waiting at least 2 hours after a dose before using a nasal decongestant, and avoiding sneezing during or right after a dose. It also warns of severe skin reactions and pseudotumor cerebri.