Some human trialsFDA approved as Factrel +1

Gonadorelin side effects

Also known as: GnRH · LHRH · Gonadotropin-releasing hormone · Gonadorelin acetate · Gonadorelin hydrochloride · Factrel · Lutrepulse

Updated Oct 24, 202621 sources

10 side effects reported for Gonadorelin: 8 from studies and labels, 2 from users and guides. 3 come with the ways people manage them.

Gonadorelin overview

Side effects reported in studies and labels

Rates as each trial or label states them. A rate from one trial does not carry over to research-grade vials or other doses.

From trials and regulators8

Clinical studies and regulatory documents.

Headache or light-headedness
Rare after a single 100 mcg dose, per the Factrel label.
Nausea or stomach discomfort
Rare after a single 100 mcg dose, per the Factrel label.
Flushing
Rare after a single dose, per the Factrel label.
Injection-site swelling, pain or itch
May occur after subcutaneous use, per the Factrel label; no rate given.
How people manage it
- Rotate injection sites.
Skin rash with long-term subQ use
Local and generalized rashes noted after chronic subcutaneous use, per the label.
Allergic reactions, including anaphylaxis
Rare, reported after repeated doses, per the Factrel label.
How people manage it
- Stop and get care for hives, wheezing, racing heart or facial swelling.
Skin redness at the pump needle site
Called a common side effect of the gonadorelin pump in a 28-man study.
Fading response over time
Pump users showed reduced sensitivity after a period of use; a short break or a higher dose restored it in one report.
How people manage it
- Guides cap daily dosing at a few days in a row for the same reason.

Side effects users and guides report

What people post and what dosing guides list. These are reports, not measured rates.

From users and guides2

Community reports, competitor and vendor guides, media.

Injection-site irritation, nausea, headache (user logs)
One site's logs: nausea 2, injection-site irritation 2, headache 1, out of 25 reports.
Testicular shrinkage despite use
Some TRT users report their testes still shrank on gonadorelin; others report it held. No numbers.

Who should avoid it, and what not to combine

Allergy to gonadorelinCondition
The only contraindication on the Factrel label.
Gonadotropin-secreting pituitary tumorCondition
The label cites a report of pituitary apoplexy and sudden blindness after GnRH in a patient with this kind of adenoma.
Drug-tested sportCondition
WADA's 2026 Prohibited List bans GnRH (gonadorelin) and its agonist analogues in male athletes (S2.2.1).

How much is known

Some human trials

Strong history for what it was approved for: a one-dose pituitary test, and pulsatile pumps that restore fertility in hypogonadotropic hypogonadism (for example 54 men in a 2025 study, 28 in 2019 and 2024 studies). For the popular use, 100 to 200 mcg shots a few times a week on TRT, we found no controlled human study.