Leuprolide: evidence, FDA status and research

It is a hormone-blocking drug used for prostate cancer, endometriosis and early puberty in children. Forty years of use and trials back it.

Sold for

Leuprolide is a mainstream hormone-suppressing drug; outside clinics it comes up mostly in debates about puberty blockers and in bodybuilding forums as a way to shut down natural testosterone.

Studies say

Controlled trials and 40 years of clinical use support the approved indications, so it grades A for prostate cancer and precocious puberty.

Why grade A. Leuprolide has four decades of controlled trials behind its prostate cancer, endometriosis, and precocious puberty indications, summarized in the adult and pediatric labels. The cited 2012 study is a randomized phase 3 trial in 84 children with precocious puberty comparing two strengths of the three-month depot, which is also the largest trial cited. The citations are thin on the original randomized prostate cancer trials, but the approvals and the labels rest on them. ¹²³

FDA. Approved. Leuprolide acetate was first approved in 1985 for advanced prostate cancer and is sold as Lupron Depot, Eligard, Camcevi, and generics for prostate cancer, endometriosis, and uterine fibroids, and as Lupron Depot-Ped and Fensolvi for central precocious puberty in children. ²³

Written from 3 cited sources. Fact-checked 2026-10-27: 18 claims checked, 5 corrected. Last refreshed 2026-10-27. Not physician reviewed.

What this means for you

What people take it for: Prostate cancer, endometriosis, fibroids and early puberty
Can a US doctor prescribe it?: Yes, FDA approved for prostate cancer, endometriosis, fibroids and early puberty.
Properly tested in people?: Yes, in large controlled trials.

Evidence checklist

Randomised controlled trial Decades of controlled trials, per labelsyes
Human study over 100 people Original trial sizes not given in articleno information
More than one research group Many trials; long approval historyyes
Clinical outcomes, not surrogate markers Disease control in prostate cancer, endometriosisyes
Human safety data beyond case reports Four decades of use; label warningsyes

Drawn from the cited studies below. A dash means the sources give no information.

What it is

Leuprolide is a synthetic nine-amino-acid analog of gonadotropin-releasing hormone (GnRH), the hypothalamic hormone that tells the pituitary to release the signals that drive testosterone and estrogen production. Two amino acid changes make it far more potent and longer-lasting than natural GnRH. ²

The FDA first approved it in 1985 as a daily injection for advanced prostate cancer. Long-acting depot forms followed: Lupron Depot in 1989, Eligard in 2002, Fensolvi for children in 2020, and the ready-to-use Camcevi for prostate cancer. The adult indications are palliative treatment of advanced prostate cancer, endometriosis, and anemia from uterine fibroids; the pediatric indication is central precocious puberty. ²³

How it works

The effect is a paradox. A short pulse of GnRH stimulates the pituitary, and in the first week or two leuprolide raises testosterone or estrogen. Continuous exposure then desensitizes the pituitary's GnRH receptors, the signals to the gonads fall, and sex hormones drop to the levels seen after surgical castration. The initial surge is why prostate cancer patients are sometimes given an anti-androgen at the start. ²

In children with central precocious puberty, the same shutdown pauses pubertal development until the drug is stopped, after which the axis restarts. ³

What human research shows

A 2012 phase 3 trial randomized 84 children with central precocious puberty at 22 US centres to one of two strengths of a three-month leuprolide depot, open-label, for six months. Peak stimulated LH, the marker that shows the pubertal signal has been switched off, was suppressed from month 2 through month 6 in 78.4% of children on the lower strength and 95.2% on the higher one. Sex-hormone suppression, growth rate, pubertal progression and adverse events were similar at both strengths. ¹

In prostate cancer, the labeled trials show testosterone falling to castrate levels in nearly all men within a few weeks and staying there for the depot interval, which is the surrogate endpoint on which the various depot formulations were approved. ²

Study	Model	Finding
Lee 2012, three-month depot in precocious puberty	Humans, n=84 children, randomized open-label phase 3, two strengths, 6 months	Peak stimulated LH was suppressed in 78.4% and 95.2% of children on the lower and higher strengths from month 2 to month 6. ¹
Lupron Depot prescribing information	FDA label summarizing controlled prostate cancer, endometriosis and fibroid trials	Testosterone reached castrate levels in nearly all men and stayed suppressed through each depot interval. ²
Lupron Depot-Ped prescribing information	FDA pediatric label	Suppression of pubertal hormones in children with central precocious puberty, with injection-site reactions the most common adverse event. ³

Safety

Side effects follow from hormone suppression: hot flashes, loss of libido, erectile dysfunction, fatigue, mood changes, and, with long use, bone density loss. In men the label warns of a transient tumor flare in the first weeks, of QT prolongation, and of higher rates of diabetes and cardiovascular events observed with androgen deprivation. Injection-site reactions are common. ²

In children, the pediatric label lists injection-site reactions, headache, and emotional lability; a transient increase in pubertal signs can occur in the first weeks. Bone density can fall during treatment, and the label cites published studies showing bone accrual is preserved after treatment stops. In the label's follow-up of treated children, most returned to pubertal LH levels within six months of stopping and girls who reached age 12 had regular periods. ¹³

Questions for your clinician

How will bone density be monitored on this drug?
What is the early flare in hormone levels, and how is it managed?
What are the long-term cardiovascular and diabetes risks with androgen deprivation?

Questions people ask

When do doctors prescribe leuprolide?

Advanced prostate cancer, endometriosis, anemia caused by uterine fibroids, and central precocious puberty in children. Different brands carry different subsets of those indications. ²³

Why does testosterone rise before it falls?

Leuprolide first stimulates the pituitary, which pushes testosterone up for a week or two. Continuous exposure then desensitizes the receptors and testosterone drops to castrate levels. ²

Is puberty suppression with leuprolide reversible?

The labeled use in central precocious puberty is designed to be stopped at the normal age for puberty. In the pediatric label's post-treatment follow-up, 87.9% of children were back to pubertal LH levels six months after stopping, and regular menstrual periods were reported in all girls who reached age 12 during follow-up. ³

Which adverse effects are most common?

Hot flashes, low libido, fatigue, mood changes, and bone loss with long use; in men, a possible tumor flare early on and higher cardiovascular and diabetes risk over time. ²

Citations

Lee 2012, J Clin Endocrinol Metab: leuprolide 3-month depot for central precocious puberty, randomized phase 3 doi.org
AbbVie: Lupron Depot (urology) US prescribing information rxabbvie.com
AbbVie: Lupron Depot-Ped US prescribing information rxabbvie.com