Gonadorelin is the body's own gonadotropin-releasing hormone made synthetically, and its dosing record is shaped by one fact: the pituitary answers GnRH only when it arrives in pulses. The medical doses are therefore tiny amounts delivered by a pump every 90 minutes, or a single larger injection used as a test. Both US human products have been discontinued; the current labels are for cattle. The one study that gave GnRH and kisspeptin to the same people, as paired tests of pituitary and hypothalamus, is reported on gonadorelin vs kisspeptin. Medibact's gonadorelin guide covers the molecule and its evidence; this page stays with figures.
What the records hold
A census run on 2026-09-28:
| Source | Result |
|---|---|
| Drugs@FDA | Factrel (NDA 018123) and Lutrepulse (NDA 019687) — both discontinued |
| DailyMed | 5 labels, all veterinary (cattle) |
| PubMed, gonadorelin in title/abstract | 296 records |
| … tagged as human | 117 |
| … tagged as clinical trial | 25 |
Most human research on GnRH pulses is indexed under "GnRH" rather than "gonadorelin", so the PubMed count understates the literature; the figures below come from records that name the product or the drug.
The human doses, by use
| Use | Dose, route and rhythm | Source |
|---|---|---|
| Ovulation induction, former US label | 5 mcg IV every 90 min, raised stepwise to 20 mcg if no response | Lutrepulse label, as quoted in the NCT01976728 protocol (Ferring, 2017) |
| Ovulation induction, SC pump trial | 10, 15 or 20 mcg SC every 90 min vs placebo | NCT01976728, 39 enrolled, completed |
| Ovulation induction, case series | 5 mcg IV or 15 mcg SC per pulse to start, every 90 min | Gynecol Endocrinol 2017 (PMID 28277105), 12 women |
| Sperm production in congenital hypogonadism | 10 mcg SC every 90 min; 7–15 mcg in another series | Zhonghua Yi Xue Za Zhi 2015 (PMID 26813133); Zhonghua Nan Ke Xue 2024 (PMID 39210488) |
| Stimulation test | 100 mcg IV, once | Presse Med 1988 (PMID 2964021) |
The pump numbers add up to modest daily totals: 16 pulses a day at 5 mcg is 80 mcg, and at 20 mcg it is 320 mcg. In the 2017 series every woman ovulated, after a mean of 17 days on the pump, with 10 pregnancies in 7 patients. In men with congenital hypogonadotropic hypogonadism, a non-randomised comparison found sperm appeared at a median of 6 months on the pump against 14 months on gonadotropin injections (Am J Mens Health 2019, PMID 30569789; 10 and 18 men), with skin reactions at the pump site common. One 1989 case report describes an antibody-mediated allergy after long-term Factrel treatment (PMID 2653043).
The veterinary labels
The only current US gonadorelin labels are for cattle. Factrel (Zoetis) is 50 mcg/mL; its label gives 2 mL, which is 100 mcg, as a single intramuscular injection for ovarian follicular cysts, and 2 to 4 mL (100–200 mcg) per cow in fixed-time insemination programmes. These are single shots to trigger ovulation in an animal, not a repeating human schedule.
What protocol pages state
A dosage page last reviewed 21 May 2026 states 50–250 mcg per subcutaneous injection, two to three times a week on non-consecutive days, from a 2 mg vial with 2 mL of water, for use alongside testosterone; it describes that use as off-label and says formal published trials of it remain limited. Set against the medical record, those amounts are 10 to 50 times one pump pulse, given a few times a week rather than every 90 minutes — a rhythm no trial found here has tested.
Units per vial size
Gonadorelin is counted in micrograms, so the table works in mcg/mL. Units on a U-100 syringe = mcg ÷ mcg/mL × 100. Research vials in this site's data are 2, 5 and 10 mg:
| Amount | 2 mg + 2 mL (1,000 mcg/mL) | 2 mg + 1 mL (2,000 mcg/mL) | 5 mg + 2 mL (2,500 mcg/mL) | 10 mg + 2 mL (5,000 mcg/mL) |
|---|---|---|---|---|
| 5 mcg (one label pulse) | 0.5 | 0.25 | 0.2 | 0.1 |
| 20 mcg (top label pulse) | 2 | 1 | 0.8 | 0.4 |
| 100 mcg (test dose) | 10 | 5 | 4 | 2 |
| 250 mcg | 25 | 12.5 | 10 | 5 |
The pulse amounts are fractions of a single syringe mark at every concentration a research vial produces, which is why pumps run far more dilute solutions: at those amounts a syringe cannot measure them. For the injection amounts, the 2 mg vial with 2 mL gives the most readable numbers. How long a vial lasts is a division: 2 mg at 100 mcg three times a week is about 6.7 weeks. The mg to mcg page covers the conversion, the insulin syringe units page the small barrels, and the gonadorelin calculator any other vial. The kisspeptin-10 dosage page reports the peptide that acts one step above it.
What is not established
No human product containing gonadorelin is currently marketed in the US, and no regulator has reviewed an intermittent twice- or thrice-weekly injection schedule. The human evidence is for pulsatile pumps and one-off tests. The half-life is not stated in the sources opened for this page. Whether a vial sold as gonadorelin contains it, and how much, is not known without an assay. Nothing on this page is a dose or a schedule.
Sources and dates
Opened 2026-09-28: Drugs@FDA through openFDA (gonadorelin); DailyMed SPL search for gonadorelin and the Factrel (Zoetis) label; ClinicalTrials.gov record NCT01976728 and its posted protocol (Ferring, dated 6 December 2017); PubMed through NCBI E-utilities (gonadorelin in title or abstract, with human and clinical-trial filters; GnRH pulse and pump searches) and the abstracts of PMIDs 2122733, 28277105, 30569789, 26813133, 39210488, 2964021 and 2653043 (title); one dosage page (last reviewed 21 May 2026), quoted for what it states. Per-day, per-vial and unit figures are arithmetic by this site. Corrections go to the contact page.