Library / Hormonal

Leuprorelin

Also known as Leuprolide, Lucrin, Eligard, Lupron

Approved medicine

Gonadotrophin releasing hormone agonist nonapeptide that suppresses sex hormones with ongoing use. Approved for hormone dependent cancers and gynaecological conditions, and used in some IVF protocols.

Prescription medicine. Only a prescriber can decide whether a medicine suits you and at what dose. This page is information, not a recommendation.

Background

Synthetic nonapeptide analogue of GnRH (des-Gly10, D-Leu6 LHRH ethylamide) developed in Japan by Takeda in the 1970s. Daily injections were first FDA approved in 1985 for prostate cancer (Lupron), followed by long acting depots.

How it is thought to work

A potent GnRH receptor agonist. It first causes a surge in LH, FSH and sex hormones (a 'flare'), then with continued exposure the pituitary shuts down, reducing testosterone or oestrogen to very low levels. This is reversible after stopping.

What is claimed, and the evidence

Claim	Evidence	Notes
Advanced prostate cancer	Approved use	FDA and TGA approved; as effective as diethylstilbestrol with fewer side effects in a 1984 randomised trial.
Endometriosis pain and lesions	Approved use	Lupron Depot 3.75 mg and 11.25 mg label indication, limited to 12 months total with add back therapy because of bone loss.
Fibroids with anaemia before surgery	Approved use	Label indication with iron therapy.
Central precocious puberty in children	Approved use	Lupron Depot-Ped label indication.

Side effects

Effect	How often	Notes
Hot flushes and sweats	Common	Over 10% in prostate cancer and gynaecology trials.
Headache, depression or mood changes, reduced libido, dizziness	Common	Over 10% in gynaecology label trials.
Injection site reactions, general pain, fatigue, oedema	Common	Over 10% in some prostate cancer depot trials.
Testicular shrinkage and erectile problems	Common	Expected effect of testosterone suppression.
Loss of bone mineral density Serious	Common	Limits treatment length in women; add back therapy reduces loss.
Tumour flare in the first weeks Serious	Common	Testosterone rises about 50% initially; can worsen bone pain, urinary obstruction or spinal cord compression.
Diabetes, raised lipids and fatty liver Serious	Frequency unknown	Metabolic syndrome warning on the label.
Heart attack, sudden cardiac death, stroke and QT prolongation Serious	Frequency unknown	Increased risk reported with GnRH analogues in men.
Convulsions Serious	Rare	Reported with or without predisposing factors.
Severe skin reactions (SJS/TEN, DRESS) Serious	Rare	Label warning; stop treatment if suspected.
Anaphylaxis Serious	Rare	Reported with GnRH agonists.

Warnings

May cause fetal harm; pregnancy must be excluded and non hormonal contraception used.
Initial hormone flare can transiently worsen cancer or endometriosis symptoms.
Long term use causes bone loss and raises metabolic and cardiovascular risks.

Regulatory status

Australia: Approved (ARTG, multiple products).
United States: FDA approved (Lupron and other products) for prostate cancer, endometriosis, fibroids and central precocious puberty.

Sources

Also in Hormonal

From the VialOwl library, reviewed 26 September 2026. For education and general information. It is not medical advice and not a recommendation to use Leuprorelin.