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Past human GnRH drug · current Factrel product is for cattle
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 a lab-made form of gonadotropin-releasing hormone (GnRH). Studies in people tested two uses. A one-time dose tests hormone release from the pituitary gland.
For treatment, a pump sends small pulses to replace weak signals from the hypothalamus, a part of the brain. The people studied had specific disorders that affect reproduction.
Human research did not use one general schedule for this drug. One test study gave a rapid 100 microgram IV dose. One small fertility study used 5–15 microgram pulses under the skin every 90 minutes.
A second used 1–5 microgram pulses from a portable pump every 96 or 120 minutes. Its checked abstract did not state the route. A male hypothalamic-hypogonadism study began with 4 micrograms under the skin every two hours.
The US sources reviewed list the past human products as discontinued, while current DailyMed records are for animals. These findings do not support use for wellness or routine use alongside testosterone replacement therapy.
What matters first
- The one-time test and repeated treatment serve different purposes: The rapid IV dose was used to test a hormone response. It does not set a daily or weekly treatment schedule.
- The treatment studies used a pump: The pump gave pulses every 90–120 minutes or every two hours to mimic the body’s own signals. The people studied had diagnosed disorders of the hypothalamus. The gaps between pulses were part of treatment. A daily total would hide them.
- US records say the human products are no longer sold: Drugs@FDA and openFDA list the human products as
Discontinued. That is their sales status. It does not by itself mean FDA withdrew approval, or show that a product for people is sold now. - 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, but the animal approval gives no use, dose or route for people. It also does not show that a human product is available or safe.
- No reviewed evidence supports a routine TRT add-on: The male study enrolled men with diagnosed hypothalamic disorders detailed in the study table. 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 applies to the group and outcomes studied. These amounts do not set a schedule for use on your own.
One-time diagnostic evidence
A diagnostic GnRH test study included 10 women who ovulated regularly and 82 with anovulation, or lack of ovulation, due to different causes. Each received one rapid 100 microgram IV dose of synthetic GnRH. Blood levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol were measured over 24 hours.
LH and FSH rose in most women, including those who were healthy and those with severe pituitary lesions. The authors said the size of the rise could not reliably identify the disease or predict its course. No rise did not always mean the pituitary had a lesion.
The one-time test could answer only limited questions and was not a treatment schedule.
Pulsatile reproductive evidence
| Study | Population and pump schedule | Reported outcome and limit |
|---|---|---|
| Subcutaneous pulsatile fertility series | Fourteen women had functional hypothalamic amenorrhea and had not responded to clomiphene. Their lack of ovulation was linked to too little GnRH signaling. They received 5–15 microgram pulses under the skin 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 study with no control group, and all the women had too little GnRH. Results per cycle do not show each woman’s chance of the same outcome. |
| Lower-dose pulsatile fertility series | Eight women did not ovulate because they had too little of their own GnRH. They received 1–5 microgram pulses by portable pump every 96 or 120 minutes during 23 cycles. | The women ovulated in twenty cycles. Five became pregnant, with seven pregnancies and four full-term births reported. The group was tiny and had no control group. |
| 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. | With pulsatile GnRH, testicular volume grew faster and by a greater amount. Testosterone rose more with gonadotropin treatment. Sperm were detected in 10/14 men tested in the GnRH group and 8/17 in the gonadotropin group. The abstract is cut short and does not say whether the groups were assigned at random. It gives neither the final GnRH dose nor the length of treatment. |
The pump and time between pulses are part of each treatment. The studies did not test a single daily or weekly dose. They also do not show the same effects on fertility or the testes in other groups.
The findings apply to the 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 discontinued for commercial and technical reasons. The FDA reviews show how the drug was used in people in the past.
They do not show that it is sold today.
FDA describes Drugs@FDA as its database of approved products. Its September 4, 2026 data page and 12-table archive list three gonadorelin-hydrochloride products under NDA 018123 and two gonadorelin-acetate products under NDA 019687. All have marketing status Discontinued.
The exact openFDA ingredient query returns the same two applications. Both list the products as Discontinued.
Discontinued describes whether the product is sold; it does not by itself mean FDA withdrew approval. The US sources reviewed show no human product now on the market.
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 join the animal approval to the past human NDA. The animal records give no dose, route or schedule for people. They also do not show that a product for people is sold now or is safe for them.
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 used to find studies, then the original trial reports were reviewed for their findings.
An empty search can miss a paper. The studies reviewed do not support routine use with TRT or for wellness. The male study tested neither use.
Those men had a disease of the hypothalamus and were not taking the drug as an add-on to TRT.
Reader questions
Is gonadorelin the same as GnRH?
Yes. Gonadorelin is synthetic gonadotropin-releasing hormone (GnRH). The salt form, route and study setting are given here when the paper reports them.
What gonadorelin doses were studied in people?
One test study gave one rapid 100 microgram IV dose. One reproductive study used 5–15 microgram pulses under the skin every 90 minutes. Another used 1–5 microgram pulses from a portable pump 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. Each schedule tested a different question in a specific group.
They do not form one dose range for general use.
Why does the pump matter?
The fertility and male studies tried to mimic GnRH signals from the hypothalamus. The frequent pulses and gaps between them were part of the treatment. Giving one daily amount or one weekly injection would change that treatment; the studies did not test either approach.
Did the diagnostic injection reliably locate a pituitary problem?
No. LH and FSH rose in most women, including those with severe pituitary lesions. The authors said the size of the rise could not reliably identify the disease or predict its course.
No rise did not always mean the pituitary had a lesion.
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. The checked human-drug databases list those products as discontinued.
The animal product does not establish current human use.
Is gonadorelin an established add-on to TRT?
The review found no trial in people testing routine use with TRT. The male study compared GnRH pulses with gonadotropin treatment in men with the disorders listed in the study table. It did not test a TRT add-on.
Can the study amounts be used as a personal schedule?
No. These amounts were used in tests to aid diagnosis or in studies of specific disorders. They do not set a personal schedule for fertility, wellness or use as an add-on to TRT.