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Historical human GnRH drug · current veterinary name collision
Gonadorelin
Gonadorelin studies tested one IV dose or repeated small pulses. They do not set a wellness schedule. Current US Factrel listings are for animals.
- A one-time test dose and repeated pulses serve different purposes.
- Current US animal-drug listings do not establish human use.
- The studies do not set a wellness or routine testosterone add-on schedule.
Gonadorelin is synthetic gonadotropin-releasing hormone (GnRH). The human evidence reviewed covers two distinct uses. One dose tests the pituitary response through gonadotropin release.
The other use replaces deficient signals from the hypothalamus. A portable pump sends frequent pulses for that purpose. Those studies enrolled people with narrowly defined reproductive disorders.
Human research did not use one general schedule for this drug. One diagnostic study gave a rapid 100 microgram IV dose. One small fertility study used 5–15 microgram pulses under the skin.
It gave them every 90 minutes. A second used 1–5 microgram pulses from a portable pump. It gave them every 96 or 120 minutes.
Its checked abstract did not state the route. A male hypothalamic-hypogonadism study began at 4 micrograms under the skin. It gave that amount every two hours.
Current US sources checked list the historical human products as stopped. Current DailyMed records for this drug are for animals. None of this evidence establishes a wellness use.
Nor does it support routine use alongside testosterone replacement therapy.
What matters first
- The one-time test and repeated treatment are separate: The rapid IV dose was a diagnostic test. It cannot become a daily or weekly treatment schedule.
- The reproductive schedules depended on a pump: The studies sought to reproduce the body’s natural pulses. They gave them every 90–120 minutes or every two hours. The people studied had disorders of the hypothalamus. These had been diagnosed. A daily total would lose a defining part of the treatment.
- The human products are historical: Current Drugs@FDA data and openFDA list the human applications as
Discontinued. That is a marketing status. It does not by itself mean approval was withdrawn. It also does not show current human availability. - Factrel names two different product histories: One historical Factrel application was for people. A currently approved Factrel product is for cattle. They share a name and ingredient. The animal approval supplies no human use, dose or route. It also supplies no human availability or safety conclusion.
- No reviewed evidence supports a routine TRT add-on: The male study had men with idiopathic hypothalamic hypogonadism. Others had Kallmann syndrome. It compared GnRH pulses with gonadotropin treatment. It did not test adding this drug to ongoing testosterone therapy.
- Every amount below was used in research: Each schedule stays tied to its study group and outcomes. The amounts do not create a consumer schedule.
One-time diagnostic evidence
A diagnostic GnRH test study included 10 women with regular ovulatory cycles. It also included 82 women with different causes of anovulation. Each received one rapid 100 microgram IV dose of synthetic GnRH.
LH, FSH and estradiol were then sampled through 24 hours.
Most people had increased LH and FSH. This included healthy women and women with severe pituitary lesions. The authors said response size was not a reliable diagnostic guide.
It also could not be relied on to predict the disease course. A negative response did not necessarily prove a pituitary lesion either. This was a one-time test with important limits on interpretation.
It was not a treatment schedule.
Pulsatile reproductive evidence
| Study | Population and pump schedule | Reported outcome and limit |
|---|---|---|
| Subcutaneous pulsatile fertility series | Fourteen infertile women with clomiphene-resistant functional hypothalamic amenorrhea received 5–15 microgram under-the-skin pulses from a portable pump every 90 minutes over 36 treatment cycles. | Ovulation occurred in 30/36 cycles; 24 cycles had normal luteal function, and 13 singleton pregnancies were reported. Two cycles had mild ovarian overstimulation. This was a small uncontrolled series in a defined GnRH-deficient population. Cycle results are not per-person probabilities. |
| Lower-dose pulsatile fertility series | Eight women whose anovulation was attributed to relative or absolute endogenous GnRH deficiency received 1–5 microgram pulses by portable pump every 96 or 120 minutes during 23 cycles. | Twenty cycles were ovulatory. Five women conceived, producing seven pregnancies and four reported full-term births. The cohort was tiny and had no comparator. |
| Male hypothalamic-hypogonadism comparison | Thirty-six men, 19 with idiopathic hypothalamic hypogonadism and 17 with Kallmann syndrome, were divided between pulsatile GnRH and gonadotropin treatment. GnRH began at 4 micrograms under the skin every two hours by portable pump. | Testicular volume increased more rapidly and by more with pulsatile GnRH, while testosterone rose more with gonadotropin treatment. Positive sperm counts occurred in 10/14 tested GnRH recipients and 8/17 tested gonadotropin recipients. The abstract is truncated, does not state random allocation, and does not supply the final GnRH dose or treatment duration. Those details remain unavailable. |
The pump and time between pulses are part of each treatment. The studies do not support a once-daily or once-weekly conversion. They also do not establish fertility or testicular outcomes in other groups.
Those results remain tied to the hypothalamic disorders studied.
Historical human products and current marketing status
A historical FDA medical review describes gonadorelin hydrochloride under NDA 018123. It says the drug was approved in 1982 for diagnostic use. A later FDA reproductive-drug review describes gonadorelin acetate under NDA 019687.
It says that drug was approved for women with hypothalamic amenorrhea. Its IV pump product was stopped for commercial and technical reasons. These documents establish historical human uses.
They do not establish current marketing.
FDA describes Drugs@FDA as its database of approved products. Its September 4, 2026 data page and 12-table archive list three gonadorelin-hydrochloride presentations under NDA 018123. They also list two gonadorelin-acetate presentations under NDA 019687.
All have marketing status Discontinued. The exact openFDA ingredient query returns the same two applications. Both have stopped statuses.
Discontinued is a marketing status. It does not by itself mean FDA withdrew approval. Current US sources checked show no human product now on the market.
That is the limit of this finding.
Why current Factrel records do not establish human use
The current DailyMed search returns five records, all for animal products. Their titles align with five FDA applications for this drug. FDA’s September 6, 2026 Approved Animal Drug Products active-ingredient index lists NADA 098-379 and ANADA 200-069.
It also lists ANADA 200-134, ANADA 200-541 and NADA 139-237.
FDA’s cattle reproductive-drug page lists five approved gonadorelin products for ovarian cysts in cattle. Four also have estrous-control uses with another animal drug. That list includes a current cattle product named Factrel.
The shared Factrel name does not connect the animal application to the historical human NDA. Animal uses, strengths, application numbers and schedules cannot establish human use. They also cannot supply a human dose or route.
Nor can they establish human availability or safety.
Unsupported wellness and TRT-adjunct claims
The exact PubMed title-and-abstract query returned zero items. The exact ClinicalTrials.gov gonadorelin and testosterone replacement query also returned zero records. A broader gonadorelin intervention query was checked to inventory the studies.
It did not replace the original trial reports.
An empty search does not prove that no paper exists. The review found no primary human evidence for routine TRT add-on use. It also found none for wellness treatment.
The male reproductive study cannot fill that gap. The men in it had disease of the hypothalamus. It did not add this drug to ongoing testosterone replacement.
Reader questions
Is gonadorelin the same as GnRH?
Gonadorelin is synthetic gonadotropin-releasing hormone. Each finding keeps its salt and route. It also keeps its study setting.
They are stated when the cited paper gives them.
What gonadorelin doses were studied in people?
One diagnostic study gave one rapid 100 microgram IV dose. One reproductive study used 5–15 microgram pulses under the skin. It gave them every 90 minutes.
Another used 1–5 microgram pulses from a portable pump. It gave them every 96 or 120 minutes. Its checked abstract did not state the route.
A male study began at 4 micrograms under the skin every two hours. These schedules tested different questions in specific groups. They cannot form one dose range for general use.
Why does the pump matter?
The fertility and male studies tried to reproduce repeated hypothalamic GnRH signals. Frequent pulses and the gaps between them defined the treatment. A daily total would describe a different treatment.
So would a weekly injection. The studies did not test either change.
Did the diagnostic injection reliably locate a pituitary problem?
No. Most people had LH and FSH responses. That included women with severe pituitary lesions.
The authors said response size was not a reliable diagnostic guide. It also could not be relied on to predict the disease course. A negative response did not necessarily prove a pituitary lesion either.
Is Factrel currently a human gonadorelin product?
Current DailyMed and FDA animal-drug sources list Factrel for cattle. A historical human Factrel application also existed. Current human databases checked list its gonadorelin presentations as stopped.
The animal product does not establish current human use.
Is gonadorelin an established add-on to TRT?
The review found no primary human trial of routine use alongside testosterone replacement therapy. The male study had men with idiopathic hypothalamic hypogonadism. Others had Kallmann syndrome.
It compared GnRH pulses with gonadotropins. It did not test a TRT add-on.
Can the study amounts be used as a personal schedule?
No. The amounts describe tests used for diagnosis. They also describe tightly defined research schedules.
They do not set a consumer fertility or wellness schedule. They also do not set a TRT add-on schedule.