Leuprolide (Leuprorelin)
Leuprolide is a synthetic 9-aa GnRH superagonist. Paradoxically, continuous use desensitizes GnRH receptors → profoundly suppresses LH, FSH, and sex steroids after 2-4 weeks. FDA-approved for prostate cancer, endometriosis, uterine fibroids, precocious puberty.
⚠ Research & Educational Use Only. Leuprolide (Leuprorelin) is a research chemical documented here for scientific education. All information references peer-reviewed literature and preclinical/clinical study data. Not for human consumption. Not medical advice. Consult a licensed researcher or healthcare professional before any laboratory use.
- Creates profound, reversible chemical castration — reduces testosterone to castrate levels (<50 ng/dL) within 2-4 weeks of continuous exposure
- FDA-approved for prostate cancer androgen deprivation therapy (standard of care for advanced disease)
- FDA-approved for endometriosis — hypoestrogenic state reduces ectopic endometrial lesions and pain
- Leuprolide (Leuprorelin) is not FDA-approved for human use. FDA-approved prescription drug (Lupron, AbbVie; generic leuprolide available). Schedule-III controlled substance in some jurisdictions. Prescription required.
Research At a Glance
- Creates profound, reversible chemical castration — reduces testosterone to castrate levels (<50 ng/dL) within 2-4 weeks of continuous exposure
- FDA-approved for prostate cancer androgen deprivation therapy (standard of care for advanced disease)
- FDA-approved for endometriosis — hypoestrogenic state reduces ectopic endometrial lesions and pain
- FDA-approved for uterine fibroids — shrinks fibroids pre-operatively
What is Leuprolide (Leuprorelin)?
Leuprolide acetate (brand names: Lupron, Eligard, Viadur) is a synthetic nonapeptide (9-amino acid) superagonist analogue of gonadotropin-releasing hormone (GnRH, also called LHRH). It was developed by the Abbott Laboratories team in 1973 and received FDA approval in 1985 for prostate cancer.
The paradoxical pharmacology of leuprolide stems from the pulsatile nature of native GnRH signaling. Endogenous GnRH is released in pulses from the hypothalamus (every 60-120 minutes in males), and pulsatile GnRH stimulates pulsatile LH and FSH release from the pituitary. Continuous (non-pulsatile) GnRH exposure, however, leads to GnRH receptor downregulation and desensitization of the gonadotrophs.
**Mechanism:** 1. Days 1-14 (flare phase): Leuprolide activates GnRH receptors → initial LH/FSH surge → testosterone elevation (~2x baseline) → "testosterone flare." This can transiently worsen prostate cancer bone pain or cause neurological complications. 2. Days 14-28 (suppression phase): Persistent GnRH receptor stimulation → receptor internalization and downregulation → gonadotroph desensitization → LH and FSH collapse → testosterone falls to castrate levels (<50 ng/dL) 3. Maintenance: Castrate testosterone levels maintained for the duration of depot activity
**Depot formulation pharmacokinetics:** The 1-month, 3-month, 4-month, and 6-month depot formulations use poly-D,L-lactic-co-glycolic acid (PLGA) microspheres or polymer rods that slowly release leuprolide over time. The Viadur implant (12-month) and Eligard formulations differ in their polymer matrix composition.
**Reversibility:** Testosterone recovery after leuprolide discontinuation occurs in approximately: - 95% of patients within 12 months - Median time to recovery: 6-9 months (varies with age, duration of therapy)
Compared to surgical castration (orchiectomy), leuprolide ADT is reversible and psychologically preferable for most patients.
Key Research Benefits
Documented effects observed in preclinical and clinical studies on Leuprolide (Leuprorelin). See all Hormonal Health peptides for comparison.
Side Effects & Risks
Adverse effects reported in the research literature. All data sourced from preclinical and clinical study reports.
Dosing Data from the Literature
Doses referenced below are sourced from published preclinical and clinical studies. Use the peptide dose calculator to convert these values to injection volume.
Leuprolide (Lupron) dosing by indication:
Prostate cancer: Lupron Depot 7.5 mg IM q28 days, 22.5 mg IM q3 months, or 45 mg IM q6 months Endometriosis: 3.75 mg IM monthly × 6 months (with norethindrone add-back to protect bone) Precocious puberty: 50 mcg/kg/day SC (pediatric) or depot formulations (7.5-15 mg IM monthly) Uterine fibroids: 3.75 mg IM monthly × 3-6 months pre-operatively
Initial antiandrogen (flutamide, bicalutamide): add for first 2 weeks to block testosterone flare in prostate cancer
Administration in Research Settings
Standard reconstitution and administration methodology for laboratory research use.
Depot formulations (microsphere or polymer suspensions) provide 1, 3, 4, or 6 month duration. IM injection into gluteal or deltoid muscle. Rotate sites. Aqueous solution (Lupron 5 mg/mL) for SC injection in daily dosing or pediatric precocious puberty.
Explore Further
Quick Reference
Research Use Only
This information is for educational research purposes only. This is not medical advice. Consult a qualified healthcare professional.