Gonadorelin

Hormone

Also known as: GnRH, LHRH, Gonadotropin-releasing hormone, Factrel (discontinued human product), Luteinizing hormone-releasing hormone

Tier 2, Investigational, human data

Studied in registered human trials with published pharmacokinetic data, but not approved. Dosing outside a trial protocol has no established safety margin.

Half-life

3.0 minutes · human data · intravenous

Native GnRH plasma half-life stated as 2-4 minutes (0.033-0.067 h) in a peer-reviewed review (PMC10201293). The widely-repeated '2-10 min distribution / 10-40 min terminal' figure could NOT be traced to a primary/allowed source and is flagged as unverified. A methods paper (PubMed 3278187) specifically cautions that peptide-hormone PK such as GnRH is often mis-modeled.

Model a dosing schedule →

Dosing

No established dose

The human diagnostic dose (single ~100 mcg IV/SC for pituitary-function testing) comes from the historical Factrel human labeling, which is discontinued and was NOT retrievable at an approved-host source during this research, so numeric dose left null rather than guessed. TRT-adjunct 'microdosing' regimens are off-label and unsupported by a label or PK study.

Regulatory status

The human product (Factrel, gonadorelin HCl, NDA 017866) for diagnostic pituitary-function testing has been discontinued and is not currently marketed in the US; the only current US DailyMed gonadorelin labels are veterinary (cattle). Some ex-US diagnostic products exist. Marked approved=false to reflect the absence of a currently marketed, FDA-approved human product for a defined indication.

Evidence base

human clinical · confidence: medium

Native hormone with a former FDA-approved diagnostic label and long clinical history; however current human PK/dosing citations at allowed hosts are limited and the specific numbers commonly quoted are hard to source.

Safety

No boxed warning. As a diagnostic agent, hypersensitivity/anaphylaxis has been reported with repeated use; chronic non-pulsatile (continuous) GnRH exposure paradoxically suppresses the gonadal axis (the basis of GnRH-agonist therapy), so dosing pattern matters clinically.

Sources