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Gonadorelin
It was a real, FDA-approved drug once — Factrel for diagnostic testing, Lutrepulse for fertility induction — both now listed as discontinued in FDA’s approval records, which do not state why. Today's off-label use, preserving fertility during testosterone therapy, has a plausible mechanism but this page cites no dedicated randomized trial showing it works for that specific purpose.
Evidence grade B: what kinds of studies support the claims on this page, with limits. It is not a verdict on any product. How we grade
On this page
In brief
Should you care? Yes, if you've heard it pitched as a fertility-safe alternative to HCG during testosterone therapy — it has a real approval history, but not for the use it's bought for now.The short version
- Genuinely approved twice, for pituitary diagnostic testing and pulsatile fertility induction — both discontinued.
- Listed as discontinued in FDA’s approval records, which do not state a reason.
- No dedicated trial supports its current off-label TRT-adjacent use.
Correction, 1 October 2026
This page previously said Factrel and Lutrepulse were “withdrawn by their manufacturers for commercial reasons, not a safety finding,” based on secondary pharmacy references. FDA’s own Drugs@FDA records show only that both products are discontinued and do not state a reason, so the page now says that and no longer gives a reason. The Library card and tracker row were corrected to match. No evidence grade changed.
Further change, 1 October 2026: the sentences about the lack of randomized-trial evidence for off-label use were reworded to say only that this page cites no such trial, and an unsourced comparison with how often HCG is used was removed.
What it is, and its real approval history
Gonadorelin is synthetic GnRH. Factrel (Wyeth) was approved for diagnostic testing of pituitary gonadotroph function; Lutrepulse was approved for pulsatile induction of ovulation in women with hypothalamic amenorrhea, delivered via a dedicated pump. FDA’s Drugs@FDA records (served through openFDA, last updated 29 September 2026) list Factrel (first approved 1982) and Lutrepulse (first approved 1989), and mark both as discontinued. The records do not say why, so this page does not give a reason. A separate FDA-approved veterinary product named Factrel exists for cattle; it is unrelated to the human products.
The real diagnostic evidence
The GnRH stimulation test — measuring LH/FSH response at set intervals after a dose — is a genuine, published diagnostic tool for distinguishing hypogonadotropic hypogonadism from constitutional delay of puberty. Worth noting precisely: much of the currently-cited diagnostic literature uses newer GnRH analogs like triptorelin rather than gonadorelin itself, a distinction that matters if you're trying to trace evidence back to this specific molecule.
Today's off-label use
Compounded gonadorelin is now widely used off-label in testosterone-therapy protocols to stimulate the testes directly, intended to preserve fertility and prevent testicular atrophy during treatment — a plausible, LH-receptor-mediated mechanism. This page cites no completed randomized trial establishing its efficacy for this specific off-label use.
What buyers should know
No FDA-approved gonadorelin product is currently marketed in the US. What's available is compounded, prescription-only, and used off-label for the TRT-adjacent purpose it's actually bought for today — not the diagnostic or fertility-induction uses it was originally approved for.
What you can do next
References
- U.S. Food and Drug Administration, Drugs@FDA application data for gonadorelin (Factrel, Lutrepulse), via openFDA, data last updated 29 September 2026: both products marked discontinued; no reason stated. open.fda.gov
- GnRH stimulation-test diagnostic literature — note that much of this research uses related GnRH analogs (e.g. triptorelin) rather than gonadorelin itself.