Pinc PeptideThe girly peptide research blog

Gonadorelin · Dose evidence · updated 8 October 2026

Gonadorelin dosage: what studies actually used

The short answer

No FDA-approved gonadorelin product for people is on the US market: Drugs@FDA lists Factrel and Lutrepulse as discontinued3. Factrel’s label used one 100 µg injection to test the pituitary4. Lutrepulse was pumped in pulses every 90 minutes, starting at 5 µg, in women whose brains make too little GnRH, and studies used 0.5 to 40 µg per pulse56. We found no study of the injections a few times a week reported for men on testosterone78.

Not dosing advice. This page reports doses that studies and approved labels used, with their sources. It does not recommend a dose, and we do not give mixing, injection or unit-conversion instructions. Gray-market vials often do not contain what their label says. How we report doses.

Every dose studied in people

StudyWhoPeopleDose and routeWhat happened
Lutrepulse pivotal studies (Canadian product monograph), four open, non-randomized studies Women aged 17 to 45: 48 with primary and 98 with secondary hypothalamic amenorrhea, 122 with other diagnoses 268 0.5 to 40 µg per pulse, every 10 to 180 minutes (most often every 90)
Pump into a vein (227 women), under the skin (13) or both (28) · Pump worn continuously for two or more weeks; 1 to 14 treatment intervals		 94% (45 of 48) of women with primary and 96% (94 of 98) with secondary hypothalamic amenorrhea ovulated6. Of 89 pregnancies with delivery data, 11 (12%) were twins or triplets6.
de Muinck Keizer-Schrama 1986, double-blind placebo-controlled trial Boys before puberty with undescended testes 252 LHRH 1.2 mg a day, or placebo
Nasal spray · 8 weeks, then a second open course		 After 8 weeks, 9% of treated testes and 8% on placebo had descended completely9. Serum testosterone did not rise9.
Christiansen 1988, modified double-blind controlled study Boys aged 1 to 13 with undescended testes 243 GnRH spray (dose not given in the abstract), hCG injections twice a week, or placebo spray
Nasal spray; hCG injected into muscle · 3 weeks of hCG; spray length not given in the abstract		 With both testes undescended, hCG did better than the GnRH spray and placebo (p = 0.0009)10. With one undescended, complete descent followed in 0% on GnRH, 3% on placebo and 14% on hCG (p = 0.07)10.
Olsen 1992, double-blind placebo-controlled multicenter trial Boys with undescended testes 141 LHRH 0.4 mg three times a day, or placebo
Nasal spray · 4 weeks		 Of 123 boys analyzed, a full response (both testes at the bottom of the scrotum) came only in six boys with both testes undescended, one of them on placebo (P = 0.12)11. Counting testes, LHRH had an effect on at least one testis in 25% of boys with both undescended (P = 0.001), but none when only one testis was undescended11.
Illig 1977, double-blind controlled trial Boys with one or both testes undescended (retractile testes excluded) 84 LHRH 1.2 mg a day in six doses, or placebo
Nasal spray · 4 weeks		 38% of 61 treated testes descended completely and another 28% improved in position, against an improved position in 25% of 51 testes on placebo12. No side effects or antibodies to LHRH were found12.
Ferring trial NCT01976728, randomized double-blind placebo-controlled trial Women aged 18 to 40 with primary hypothalamic amenorrhea 39 10, 15 or 20 µg per pulse every 90 minutes, or placebo
Wearable pump under the skin (OmniPod) · Planned for about 37 days		 Among women treated for at least 14 days, ovulation in 1 of 9, 4 of 9 and 5 of 9 women on 10, 15 and 20 µg, against 0 of 10 on placebo13. Breast tenderness and hot flushes occurred only on 15 and 20 µg, and no one had a serious side effect13.
Rajfer 1986, randomized double-blind trial against hCG Boys aged 1 to 5 with undescended testes 33 GnRH 1.2 mg a day, or hCG 3300 IU a week
GnRH nasal spray; hCG injection · 28 days of GnRH; 4 weeks of hCG		 Testes descended in 3 of 16 boys (19%) on GnRH and 1 of 17 (6%) on hCG (P = 0.23)14. Testosterone rose in both groups, more with hCG, and the authors judged both treatments ineffective in most cases14.
Zhang 2019, nonrandomized open-label comparison Males aged 16 to 34 with congenital hypogonadotropic hypogonadism (born with too little GnRH) and no sperm 28 Gonadorelin 10 µg every 90 minutes at first (10 men), or hCG 2,000 IU three times a week, with hMG 75 IU three times a week added in alternating 3-month blocks (18 men)
Pump under the skin; hCG injected into muscle, hMG injected (route not stated) · Up to 24 months		 Pump doses were adjusted to hormone levels: one man went up to 15 µg, two others were raised and one went down to 3 µg15. Sperm appeared after a median of 6 months on the pump and 14 months on injections (p = .01)15.
Manfredi-Lozano 2022, open-label pilot study Men with Down syndrome, average age 26.4 7 75 ng/kg per pulse every 2 hours
Pump under the skin (LutrePulse) · 6 months		 Total score on a cognitive screening test rose in 6 of 7 men, and the treatment was well tolerated16. There was no placebo or untreated comparison group16.
Factrel label, LH response tests in normal adults Normal adult men and women (the label’s reference tests) – One 100 µg dose
Injection under the skin or into a vein · Single dose		 In men, LH, the pituitary hormone gonadorelin releases, peaked at a mean of 34 minutes after the injection under the skin (18 tests) and 27 minutes after the vein injection (26 tests)4. In women, the means were 71.5 and 36 minutes (38 and 31 tests)4.

Studies, animals and users: kept apart

Doses below are what studies used or what a label says. They are not advice, and gray-market products may not contain what their label says.

In human studies

Factrel’s label used a single 100 µg dose, under the skin or into a vein, for the pituitary test4. Lutrepulse’s original US label started at 5 µg into a vein every 90 minutes, raised stepwise up to 20 µg if there was no response5. The Canadian label starts at 5 µg under the skin every 90 minutes and notes that 1 to 20 µg have been used in studies6. The pivotal pump studies used 0.5 to 40 µg per pulse, every 10 to 180 minutes6, and Ferring’s 2014 to 2018 trial used 10, 15 or 20 µg every 90 minutes for about 37 days513. In men born with too little GnRH, one study started at 10 µg every 90 minutes by pump15. A Down syndrome pilot used 75 ng/kg per pulse every 2 hours for 6 months16. Nasal-spray trials in boys used 1.2 mg a day for 4 weeks12, 28 days14 or 8 weeks9, or 0.4 mg three times a day for 4 weeks11. We found no trial of injections a few times a week, the pattern reported for men on testosterone7817.

In animal studies

Not applicable or not reported.

What users report Anecdotal · not validated · not a recommendation

A peptide-information website (reviewed 30 July 2026) says community use is commonly around 100 µg under the skin a couple of times a week8.

Half-life and how it is taken

Half-life
About 2 to 10 minutes at first, then about 10 to 40 minutes6Initial and terminal half-lives of GnRH in blood after an injection into a vein or under the skin. The Canadian Lutrepulse monograph says they are similar in healthy volunteers and in men and women whose brains make too little GnRH, and similar for single injections and pump pulses. Kidney failure, but not liver disease, lengthens the half-life.
Routes
  • Pump pulses under the skin, usually every 90 minutes (the Canadian label and recent trials; human data)
  • Pump pulses into a vein (the original US Lutrepulse; human data)
  • Single injection under the skin or into a vein (the Factrel pituitary test; human data)
  • Nasal spray (trials in boys with undescended testes; human data)
  • Skin patch driven by a small electric current (one completed trial in women; no results posted)
  • Injections under the skin a few times a week (the pattern reported for men on testosterone; we found no trial data)

What the discontinued labels said

Neither US label is on FDA’s site: Drugs@FDA lists Factrel (NDA 018123) and the Lutrepulse Kit (NDA 019687) as discontinued and says the label is not available for either12. DailyMed, the US label library, has five gonadorelin labels, all for animals18. So the label details on this page come from a reproduced Factrel label, Ferring’s 2017 trial protocol and the 2016 Canadian Lutrepulse monograph456.

Drugs@FDA lists Factrel vials of 0.1, 0.2 and 0.5 mg1. Factrel was given once, as a test of the pituitary4. Blood was drawn 15 minutes before and just before the injection, then 15, 30, 45, 60 and 120 minutes after it, to measure the rise in LH4. The label said safety and effectiveness in children had not been established4.

Lutrepulse was approved in the US on 10 October 1989319. Its orphan designation covered inducing ovulation in women with hypothalamic amenorrhea caused by too little GnRH or the wrong pulse pattern19. The Canadian label says most women with primary hypothalamic amenorrhea ovulate during their first treatment cycle at 5 µg, though some do not respond to that dose6.

Ovulation by dose in the label’s studies

The Canadian label breaks down ovulation in the pivotal studies by dose per pulse, at one pulse every 90 minutes. It counts treatment regimens rather than women, and each woman had 1 to 14 treatment intervals6.

  • Into a vein, primary hypothalamic amenorrhea: 75% (39 of 52) under 6 µg, 75% (3 of 4) at 6 to 10 µg, 91% (64 of 70) at 11 to 20 µg and 0% (0 of 1) above 20 µg6.
  • Into a vein, secondary hypothalamic amenorrhea: 90% (118 of 131) under 6 µg, 67% (4 of 6) at 6 to 10 µg and 85% (63 of 74) at 11 to 20 µg6.
  • Under the skin, primary: 27% (3 of 11) under 6 µg (the label prints ‘<6 pg’, apparently a typo), 100% (6 of 6) at 6 to 10 µg and 83% (33 of 40) at 11 to 20 µg6.
  • Under the skin, secondary: 75% (24 of 32), 80% (4 of 5) and 89% (31 of 35) at the same three dose levels6.

The label is not consistent about route. In the pivotal studies, 7% (4 of 61) of regimens under the skin led to pregnancy in women with primary hypothalamic amenorrhea, against 19% (33 of 175) into a vein6. Yet the same label reports a separate three-year assessment in which pregnancy rates were higher under the skin (78.4% vs 59.4%, p = 0.016)6.

The label says published work by other investigators supports these results6. About 816 women took part in those studies, which used 0.2 µg to 500 µg per pulse and pulses from a single dose to one every 24 hours6.

Why the pulse pattern matters

The fertility results in the table came from pumps that gave pulses, most often every 90 minutes, day and night, copying the brain’s own rhythm5615. The Canadian label says that with pulses, LH and FSH patterns in general do not differ markedly from those of normal menstrual cycles, while continuous exposure ‘could temporarily reduce pituitary responsiveness’6.

A 2026 review says GnRH’s effect depends on pulsed delivery, and that the need for special pumps, high cost and limited availability keep it for specific conditions rather than routine care of testosterone-related suppression20. Factrel’s label warned that repetitive, high doses may cause ‘inhibition of spermatogenesis’, meaning less sperm production4.

What compounded and research vials contain

We found no independent lab test of gonadorelin vials, so whether they hold the amount on the label is unknown21. USP’s standard for the powder, revised in 2025, describes it as gonadorelin with unspecified amounts of acetic acid and water, and requires 95% to 105% gonadorelin once those are excluded22. In March 2022, a Kentucky compounder and a Florida pharmacy recalled gonadorelin injections for lack of sterility assurance23.

Questions people ask

How much gonadorelin should I take?

We found no trial in men on testosterone, so we know of no tested dose for them, and no FDA-approved gonadorelin product for people is on the US market3717. Labels and trials used one 100 µg test dose, or pump pulses of 5 to 20 µg every 90 minutes in people whose brains make too little GnRH456. Ask a prescriber whether any dose fits you.

How often is gonadorelin given?

On the discontinued labels, either once, for the pituitary test, or as a pulse every 90 minutes from a pump worn day and night456. The Canadian pump could be set to pulse every 90 or 120 minutes6. Neither matches the injections a couple of times a week that a community site describes8.

How long does gonadorelin take to work?

In the Lutrepulse studies of women with primary hypothalamic amenorrhea, ovulation rarely came in fewer than 10 days (under 5% of treatment intervals); in half of the successful intervals it came after day 15, and in 95.3% (162 of 170) by day 286. In men born with too little GnRH, sperm appeared after a median of 6 months on a pump15.

Where does the 100 µg gonadorelin dose come from?

Not from a trial: the community site that reports it calls it ‘community convention, not a trial dose’8. The only 100 µg dose on a US label for people was Factrel’s single injection to test how the pituitary responds4.

Go deeper

Sources

  1. 1Drugs@FDA: FACTREL (gonadorelin hydrochloride), NDA 018123, marketing status and label availability U.S. Food and Drug Administration, accessed 8 Oct 2026. accessdata.fda.gov
  2. 2Drugs@FDA: LUTREPULSE KIT (gonadorelin acetate), NDA 019687, marketing status and label availability U.S. Food and Drug Administration, accessed 8 Oct 2026. accessdata.fda.gov
  3. 3Drugs@FDA via openFDA: applications containing gonadorelin (NDA 018123 Factrel, NDA 019687 Lutrepulse) U.S. Food and Drug Administration (openFDA), 7 Oct 2026. api.fda.gov · data query
  4. 4Factrel (Gonadorelin): Side Effects, Uses, Dosage, Interactions, Warnings RxList, 8 Aug 2022. rxlist.com
  5. 5A Multicenter, Double-Blind, Randomized, Placebo-Controlled Study Evaluating Three Doses of Subcutaneous Pulsatile GnRH Administered via OmniPod Pump: clinical trial protocol, amendment 7 (NCT01976728) Ferring Pharmaceuticals, via ClinicalTrials.gov, 6 Dec 2017. cdn.clinicaltrials.gov
  6. 6LUTREPULSE (gonadorelin acetate) product monograph Ferring Inc. via Health Canada Drug Product Database, 17 May 2016. pdf.hres.ca
  7. 7PubMed search: gonadorelin with testosterone or TRT in the title or abstract (24 results; none gave gonadorelin to men taking testosterone) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov
  8. 8Gonadorelin: How It Works, Mechanism & Evidence (2026) The Peptide Catalog, 30 Jul 2026. thepeptidecatalog.com
  9. 9Double-blind, placebo-controlled study of luteinising-hormone-releasing-hormone nasal spray in treatment of undescended testes Lancet, 19 Apr 1986. pubmed.ncbi.nlm.nih.gov
  10. 10Treatment of cryptorchidism with human chorionic gonadotropin or gonadotropin releasing hormone. A double-blind controlled study of 243 boys Hormone Research, 1988. pubmed.ncbi.nlm.nih.gov
  11. 11Management of the non-descended testis: doubtful value of luteinizing-hormone-releasing-hormone (LHRH). A double-blind, placebo-controlled multicentre study International Journal of Andrology, Apr 1992. pubmed.ncbi.nlm.nih.gov
  12. 12Treatment of cryptorchidism by intranasal synthetic luteinising-hormone releasing hormone. Results of a collaborative double-blind study Lancet, 10 Sep 1977. pubmed.ncbi.nlm.nih.gov
  13. 13LutrePulse Hypogonadotropic Hypogonadism (NCT01976728), registry record with results ClinicalTrials.gov, 3 Mar 2021. clinicaltrials.gov
  14. 14Hormonal therapy of cryptorchidism. A randomized, double-blind study comparing human chorionic gonadotropin and gonadotropin-releasing hormone New England Journal of Medicine, 20 Feb 1986. pubmed.ncbi.nlm.nih.gov
  15. 15The Pulsatile Gonadorelin Pump Induces Earlier Spermatogenesis Than Cyclical Gonadotropin Therapy in Congenital Hypogonadotropic Hypogonadism Men American Journal of Men’s Health, 2019. pubmed.ncbi.nlm.nih.gov
  16. 16GnRH replacement rescues cognition in Down syndrome Science, 2 Sep 2022. pubmed.ncbi.nlm.nih.gov
  17. 17ClinicalTrials.gov search for ‘gonadorelin AND “testosterone replacement”’ (3 records, none giving gonadorelin to men on testosterone) ClinicalTrials.gov, accessed 8 Oct 2026. clinicaltrials.gov
  18. 18DailyMed label search: gonadorelin (5 results, all animal drugs) DailyMed (U.S. National Library of Medicine), accessed 8 Oct 2026. dailymed.nlm.nih.gov
  19. 19Orphan drug designation: gonadorelin acetate (Lutrepulse) for induction of ovulation in women with hypothalamic amenorrhea U.S. Food and Drug Administration, Office of Orphan Products Development, 22 Apr 1987. accessdata.fda.gov
  20. 20Emerging peptide and neuroendocrine strategies for TRT-induced reproductive suppression and functional male hypogonadism: a narrative review Frontiers in Reproductive Health, 2026. pubmed.ncbi.nlm.nih.gov
  21. 21Finnrick public data summary (llms-full.txt, generated 25 September 2026) Finnrick, 25 Sep 2026. finnrick.com
  22. 22USP Monographs: Gonadorelin Acetate (USP-NF, 2025 revision) United States Pharmacopeia, 2025. doi.usp.org
  23. 23FDA drug recall (enforcement report) records for products described as gonadorelin, via the openFDA drug/enforcement API (3 records) U.S. Food and Drug Administration (openFDA), 30 Sep 2026. api.fda.gov · data query

Not medical advice. Talk to a licensed clinician before using any drug. Report an error.