Leuprolide
Lupron · Lupron Depot · Eligard
A synthetic GnRH agonist that paradoxically suppresses the HPG axis with continuous use, used clinically for prostate cancer, endometriosis, and off-label in hormone optimization and fertility research.
Half-Life
~3 hours (subcutaneous); depot formulations provide continuous release over weeks-months
MW
1209.4 Da
Amino Acids
9 AA
Evidence
High Evidence
Regulatory Status
FDA-approved for multiple indications. Prescription-only. Available as daily subcutaneous injection or depot formulations (1-month, 3-month, 6-month implants). Controlled substance in some countries.
In Plain English
A synthetic version of the hormone signal that normally triggers testosterone production — but when given continuously, it actually shuts down testosterone completely. This counterintuitive effect (too much signal = receptor burnout = no signal) is used to treat prostate cancer, endometriosis, and control hormones during IVF. The shutdown is reversible when you stop.
Overview
Leuprolide is a nonapeptide (9 AA) synthetic analog of gonadotropin-releasing hormone (GnRH/LHRH) with D-Leu6 and N-ethylamide substitutions that increase receptor binding affinity and plasma stability compared to native GnRH. While acute administration stimulates LH and FSH release, continuous or depot administration causes GnRH receptor downregulation and desensitization, leading to profound suppression of LH, FSH, testosterone (in males), and estrogen (in females) — a state called "medical castration." FDA-approved for prostate cancer, endometriosis, uterine fibroids, precocious puberty, and as part of IVF protocols. In the TRT/hormone optimization community, leuprolide is researched for testosterone suppression protocols, fertility preservation, and as part of advanced hormonal management strategies.
Common Formats
- Daily subcutaneous injection (1 mg/day)
- Depot injection (3.75–22.5 mg, 1–6 month)
- Subcutaneous implant
Storage Notes
Daily formulation: refrigerate at 2-8°C. Depot microspheres: room temperature storage, mix with diluent immediately before use. Do not freeze depot formulations.
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Related Compounds
Gonadorelin
The endogenous hypothalamic hormone that regulates the HPG axis through pulsatile GnRH receptor signaling, used in fertility and hormonal research.
Triptorelin
A synthetic decapeptide GnRH agonist used clinically for prostate cancer, endometriosis, precocious puberty, and researched for HPTA restoration after anabolic steroid use.
Kisspeptin
An endogenous neuropeptide and master regulator of the HPG axis, GnRH release, and reproductive function with significant clinical research interest.
Educational Disclaimer: All information on this page is for educational and research purposes only. This does not constitute medical advice, diagnosis, or treatment recommendation. Consult a qualified healthcare professional.