Nafarelin Reference

Plain English

What it is

Nafarelin (brand name Synarel) is an FDA-approved prescription nasal spray. It is a GnRH agonist, a lab-made copy of a natural hormone signal that, when used steadily, lowers the body's sex hormones (especially estrogen).

What people use it for

Doctors prescribe it to ease the pain of endometriosis and shrink its tissue growths in women, and to treat central precocious puberty (puberty that starts far too early) in children. It is taken as a nose spray at home after a prescriber shows the person how to use it.

What the science shows

It has solid human evidence from controlled trials. For endometriosis it eased pelvic pain and reduced the lesions about as well as an older comparison drug, and for early puberty it quiets the signals that drive it while still allowing normal adult height.

The catch

This is a prescription medicine, and self-treating is unsafe. Keeping estrogen low for a long time thins the bones, and some of that loss may not come back, so the label limits how long and how many times it can be used and discourages repeat courses. Common effects include hot flashes, headaches, vaginal dryness, and mood swings. Pregnancy must be ruled out before starting, and nonhormonal birth control is used during treatment.

Reference summary

Nafarelin is a label-verified intranasal GnRH agonist with multiple Phase 3 and post-marketing trials in endometriosis (Henzl 1988 NEJM and follow-on studies) showing pelvic-pain and lesion-size endpoints comparable to depot agonists, and a separate label evidence base in central precocious puberty showing pituitary downregulation with maintained adult-height outcomes. The hypoestrogenic state during continuous suppression drives a measurable bone-density loss that increases with cumulative treatment length, and the label caps endometriosis courses accordingly.

Regulatory and posture

Categories

Reproductive, Hormonal

Aliases

Synarel, Intranasal GnRH agonist, Nafarelin acetate, RS-94991

Evidence posture

human - Endocrinology drug. Prescription-only; off-label or self-administered use is unsafe. Bone-density loss accumulates with prolonged hypoestrogenic exposure, the label caps endometriosis courses, and add-back hormonal therapy is a common label-discussed mitigation.

Regulatory status

FDA-approved prescription medication (Synarel). Indications include endometriosis (in women) and central precocious puberty (in children). Prescription-only and patient self-administered as an intranasal spray after prescriber training.

Content review status

label verified