Leuprolide

approved

Also known as: Lupron, Leuprorelin, Eligard

Leuprolide is a synthetic gonadotropin-releasing hormone (GnRH) agonist that acts on pituitary GnRH receptors. Upon initial administration, it causes a transient surge in luteinizing hormone (LH) and follicle-stimulating hormone (FSH), leading to a temporary increase in sex-steroid levels. With continuous exposure, however, receptor desensitization and downregulation occur, resulting in profound suppression of LH and FSH secretion and subsequent reduction of gonadal testosterone or estradiol to castrate or postmenopausal levels. This paradoxical inhibitory effect forms the basis for its therapeutic utility in hormone-sensitive conditions. Key research findings from over 2,300 PubMed-indexed studies demonstrate leuprolide’s efficacy in advanced prostate cancer, where it achieves medical castration comparable to surgical orchiectomy. In endometriosis, it reduces lesion size and pain symptoms by inducing a hypoestrogenic state. For central precocious puberty, it halts premature sexual development and preserves adult height potential. Long-term safety data indicate manageable adverse effects related to hypoestrogenism (e.g., hot flashes, bone density loss) and initial tumor flare in prostate cancer, which can be mitigated with concurrent antiandrogen therapy. Clinically, leuprolide is approved for use in prostate cancer (palliative treatment), endometriosis (limited to 6 months due to bone loss), and precocious puberty (in children). Its depot formulations (monthly, 3-month, 6-month) improve compliance. Despite its established role, newer GnRH antagonists offer faster suppression without the initial flare, though leuprolide remains a cornerstone due to extensive evidence and cost-effectiveness. For research purposes only — not medical advice.

Key data

Category
Hormonal & Endocrine
Molecular weight
1209.4 g/mol
Molecular formula
C59H84N16O12
CAS number
53714-56-0
Administration
subcutaneous, intramuscular
Research status
approved
References
2,340
Tags
gnrh-agonist, approved, oncology

Research & studies

Leuprolide
2026 · PubMed
Treatment of High-Risk Biochemically Recurrent Prostate Cancer With Enzalutamide in Combination With Leuprolide: Secondary End Points From the EMBARK Trial
The Journal of urology · 2026 · PubMed
Enzalutamide Monotherapy for the Treatment of Prostate Cancer With High-Risk Biochemical Recurrence: EMBARK Secondary End Points
The Journal of urology · 2026 · PubMed
Improved Survival with Enzalutamide in Biochemically Recurrent Prostate Cancer
The New England journal of medicine · 2026 · PubMed

8-year overall survival was 78.9% with enzalutamide plus leuprolide vs. 69.5% with leuprolide alone (HR 0.60, p<0.001).; Enzalutamide monotherapy did not significantly improve overall survival vs. leuprolide alone (73.1% vs. 69.5%; HR 0.83, p=0.19).; Descriptive updates for secondary end points were consistent with prior metastasis-free survival results.; Safety findings were consistent with the primary analysis.

Enzalutamide with or without leuprolide in patients with high-risk biochemically recurrent prostate cancer: EMBARK post hoc analysis by age
European journal of cancer (Oxford, England : 1990) · 2026 · PubMed

Improvements in metastasis-free survival with enzalutamide plus leuprolide or enzalutamide alone were observed across both age groups.; Treatment-related serious adverse events were low in all groups (0.6-11.7%) but more frequent in patients aged ≥70 years.; Grade 3 adverse events ranged from 36.3% to 60.1% across treatment and age groups, with higher rates in older patients.; Clinically meaningful metastasis-free survival benefits were seen regardless of age, though subgroup sizes were small.

Impact of treatment suspension on health-related quality of life in the EMBARK trial: a post hoc analysis
EClinicalMedicine · 2025 · PubMed

Treatment suspension occurred in 90% of enzalutamide + leuprolide, 86% of enzalutamide monotherapy, and 67% of leuprolide alone groups.; No meaningful change in HRQoL was found after suspension across all PRO instruments except hormonal treatment-related symptoms.; Clinically meaningful improvement in hormonal symptoms was seen at week 61 (enzalutamide monotherapy), week 73 (leuprolide alone), and week 85 (enzalutamide + leuprolide).; Further real-world studies are needed to explore benefits of treatment suspension.

Effects of Enzalutamide on the Sexual Activity of Patients with Biochemically Recurrent Prostate Cancer: A Post Hoc Analysis of Patient-reported Outcomes in the EMBARK Study
European urology · 2025 · PubMed

Enzalutamide monotherapy delayed deterioration in interest in sex (median 8.5 vs 5.6 months; HR 0.70).; Enzalutamide monotherapy delayed deterioration in extent of sexual activity (median 5.7 vs 3.0 months; HR 0.69).; Enzalutamide monotherapy delayed deterioration in satisfaction with sex life (median 11.1 vs 5.4 months; HR 0.61).; Enzalutamide monotherapy delayed deterioration in erectile function (median 5.5 vs 2.9 months; HR 0.67).

Testosterone Recovery for Relugolix Versus Leuprolide in Men with Advanced Prostate Cancer: Results from the Phase 3 HERO Study
European urology oncology · 2024 · PubMed

Cumulative incidence of testosterone recovery to >280 ng/dl at 90 days was 54% for relugolix vs 3.2% for leuprolide acetate.; Median time to testosterone recovery was faster with relugolix (86.0 days) than leuprolide acetate (112.0 days).; More men on relugolix achieved 80% of baseline testosterone levels (39% vs 2.1%).; Adverse events were generally similar between treatment groups.

Frequently asked questions

What is Leuprolide?

Leuprolide is a synthetic gonadotropin-releasing hormone (GnRH) agonist that acts on pituitary GnRH receptors. Upon initial administration, it causes a transient surge in luteinizing hormone (LH) and follicle-stimulating hormone (FSH), leading to a temporary increase in sex-steroid levels. With continuous exposure, how

How does Leuprolide work?

GnRH agonist that suppresses gonadotropin and sex-steroid production after initial stimulation; used in prostate cancer, endometriosis, and precocious puberty.

What is the research status of Leuprolide?

Leuprolide is currently classified as approved, with 2,340 research references on record. This is for research purposes only and is not medical advice.

What is the molecular weight of Leuprolide?

Leuprolide has a molecular weight of approximately 1209.4 g/mol (formula C59H84N16O12).

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