Hormone medicines
Nafarelin
A GnRH agonist with labeled uses in central precocious puberty and endometriosis, plus clinical evidence that requires attention to bone and mood effects.
Randomized endometriosis trials and US prescribing information; population-specific benefit and risks
Also known as: Synarel
Practical use
Evidence interpretation and clinical context
- Keep the indication attached
- Pediatric puberty treatment and adult endometriosis are different evidence contexts.
- Check attrition
- The quality-of-life study lost a substantial number of participants.
- Separate during from after
- State when mood and symptom changes were measured.
Changes in quality of life after hormonal treatment of endometriosis.
Overview
Nafarelin is supplied as the prescription nasal product Synarel. Sustained GnRH-receptor stimulation suppresses pituitary-gonadal signaling. The pediatric puberty indication and adult endometriosis indication address different diseases and should remain separate.
Risks and limitations
The US label addresses bone-mineral loss, pregnancy-related harm and reports of seizures and psychiatric events. In an endometriosis quality-of-life trial, anxiety-depression scores worsened during nafarelin treatment even though some later outcomes improved.
How to read this
A nasal route does not make a hormone-active medicine local to the nose. The intended effects involve the reproductive endocrine axis throughout the body.
Research explained
A randomized, parallel, comparative study of the efficacy and safety of nafarelin versus danazol in the treatment of endometriosis in Taiwan.
Who was studied
59 Taiwanese women with confirmed endometriosis randomized to nafarelin or danazol for 180 days.
What was found
Both groups improved in symptoms and laparoscopic scores, without a significant efficacy difference. Nafarelin had fewer selected liver-enzyme and lipid changes than danazol.
What it cannot establish
The comparator was an active medicine. Relative laboratory tolerability does not establish absence of adverse effects or superiority to all alternatives.
Read the original studyChanges in quality of life after hormonal treatment of endometriosis.
Who was studied
48 women in a blinded randomized comparison of nafarelin and medroxyprogesterone; 30 completed the study.
What was found
Symptoms improved without a significant difference between treatments. Anxiety-depression increased during nafarelin treatment, while some quality-of-life measures improved later.
What it cannot establish
Substantial dropout and baseline psychosocial differences between completers and dropouts limit interpretation. Later improvement should not erase symptoms experienced during treatment.
Read the original studyCurrent US product scope
Synarel’s label includes central precocious puberty in children and endometriosis management in adults. The clinical purpose, monitoring and evidence differ between those indications.
Supporting sourceWhy follow-up timing changes the story
Quality of life during treatment and after treatment are separate outcomes. A later average improvement can coexist with an earlier deterioration in a specific symptom domain.
Supporting sourceClaims versus findings
Incorrect
A nasal hormone medicine has only local effects.
Nafarelin’s intended mechanism suppresses systemic reproductive-hormone signaling.
Check the evidenceCommon questions
Did the comparative trial prove fewer harms than every other GnRH medicine?
No. It compared nafarelin with danazol; those data do not establish superiority to untested comparators.
SourceSources
Changes in quality of life after hormonal treatment of endometriosis.
Current US product scope — primary or official source
Sources checked 2026-10-01.
General education; not a personal treatment plan.