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.

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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 lab-made version of gonadotropin-releasing hormone (GnRH). It has nine amino acids. GnRH is the hypothalamic hormone that tells the pituitary to release the signals that drive testosterone and estrogen production. Two amino acid changes make leuprolide 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 came in 1989 and Eligard in 2002. Fensolvi for children came in 2020. Camcevi, a ready-to-use form, treats prostate cancer. In adults, the approved uses are palliative treatment of advanced prostate cancer, endometriosis, and anemia from uterine fibroids. In children, the approved use is central precocious puberty. ²³

How it works

The effect is a paradox. A short pulse of GnRH stimulates the pituitary. So in the first week or two, leuprolide raises testosterone or estrogen. Then continuous exposure numbs the pituitary's GnRH receptors. The signals to the gonads fall. Sex hormones drop to the levels seen after surgical castration. The early surge is why prostate cancer patients sometimes get an anti-androgen at the start. ²

In children with central precocious puberty, the same shutdown pauses puberty until the drug is stopped. After that the axis restarts. ³

What human research shows

A 2012 phase 3 trial randomized 84 children with central precocious puberty at 22 US centres. They got one of two strengths of a three-month leuprolide depot, open-label, for six months. Peak stimulated LH is the marker that shows the pubertal signal is switched off. It was suppressed from month 2 through month 6 in 78.4% of children on the lower strength. On the higher strength it was 95.2%. 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. It stays there for the depot interval. That level is the surrogate measure on which the various depot forms 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. They include hot flashes, loss of libido, erectile dysfunction, fatigue and mood changes. With long use, bone density can fall. In men the label warns of a brief tumor flare in the first weeks. It also warns of QT prolongation. And it warns of higher rates of diabetes and cardiovascular events seen with androgen deprivation. Injection-site reactions are common. ²

In children, the pediatric label lists injection-site reactions, headache and emotional lability. Signs of puberty can briefly increase in the first weeks. Bone density can fall during treatment. The label cites published studies showing that bone gain is preserved after treatment stops. The label also followed treated children afterward. Most returned to pubertal LH levels within six months of stopping. 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 approved uses. ²³

Why does testosterone rise before it falls?

Leuprolide first stimulates the pituitary. That pushes testosterone up for a week or two. Then continuous exposure numbs the receptors, and testosterone drops to castrate levels. ²

Is puberty suppression with leuprolide reversible?

The labeled use in central precocious puberty is meant to be stopped at the normal age for puberty. The pediatric label followed children after treatment. Six months after stopping, 87.9% were back to pubertal LH levels. All girls who reached age 12 during follow-up reported regular periods. ³

Which adverse effects are most common?

Hot flashes, low libido, fatigue and mood changes. 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