Clinical / PharmaceuticalAlso known as: Leuprolide, Lupron, Eligard, GnRH agonist

Leuprorelin

Leuprorelin is an incredibly potent synthetic agonist of Gonadotropin-Releasing Hormone (GnRH). It is the absolute pharmaceutical apex for establishing total, reversible endocrine suppression. Administered commonly as a long-acting depot, it is clinically deployed to forcefully execute medical castration in advanced, hormone-dependent prostate and breast cancers, violently halt the progression of severe endometriosis, and stop central precocious puberty dead in its tracks.

Reviewed by CalcMyPeptide Editorial Team

·Last updated: April 2026·Evidence: High·1 peer-reviewed citation

Quick Stats

Half-Life~3 hours (but formulated as depot depot for 1-6 months)

Dose Range3.75-22.5 mg depot (monthly-quarterly)

FrequencyMonthly or every 3-6 months (depot)

Vial SizesN/A (oral)

BioavailabilityIntramuscular or subcutaneous depot injection

Year Developed1970s (FDA approved 1985)

Scientific Data

Molecular Formula

C59H84N16O12

Molecular Weight

1209.4 g/mol

CAS Number

53714-56-0

PubChem ID

5482319

Developer

Abbott Laboratories (Takeda)

Mechanism of Action

Leuprorelin (Lupron) is a highly potent synthetic nonapeptide analog of gonadotropin-releasing hormone (GnRH). It acts as a GnRH receptor agonist at the anterior pituitary. While pulsatile GnRH stimulates hormone production, the continuous administration of leuprorelin leads to a brief initial surge (flare) followed by profound receptor downregulation and desensitization.

This medical castration effect completely suppressses luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion, dropping testosterone in men and estrogen in women to castrate/menopausal levels. It is an essential treatment in hormone-responsive cancers (prostate, breast), endometriosis, and central precocious puberty.

Source: PMID: 8613886

Background & History

Leuprorelin (leuprolide acetate) is one of the most prescribed GnRH agonists worldwide. Originally developed for prostate cancer, its ability to suppress gonadal steroids has expanded applications to endometriosis, uterine fibroids, central precocious puberty, and assisted reproduction. Depot formulations (Lupron Depot, Eligard) allow monthly, quarterly, or biannual administration.

Research Use Cases

✓Advanced prostate cancer
✓Endometriosis
✓Central precocious puberty
✓Uterine fibroids
✓Assisted reproduction

Dosing Protocol

Typical Dose	3.75-22.5 mg depot (monthly-quarterly)
Frequency	Monthly or every 3-6 months (depot)
Half-Life	3 hours

Dosing Protocols

Oncology / Endometriosis

Dose

3.75 - 22.5 mg Depot

Frequency

Monthly, 3-month, or 6-month injections

Note: Given strictly under medical supervision. Typically mixed into polymer microspheres for slow release.

Body-Weight Dosing Reference

Estimated doses extrapolated from the published research range of 3750–22500 mcg/day (referenced to 70 kg / 154 lb). These are approximations — consult a qualified healthcare provider for personalised guidance.

Weight	Low Dose	Target Dose	High Dose
120 lb(54 kg)	2893 mcg	10125 mcg	17357 mcg
140 lb(63 kg)	3375 mcg	11813 mcg	20250 mcg
160 lb(73 kg)	3911 mcg	13688 mcg	23464 mcg
180 lb(82 kg)	4393 mcg	15375 mcg	26357 mcg
200 lb(91 kg)	4875 mcg	17063 mcg	29250 mcg
220 lb(100 kg)	5357 mcg	18750 mcg	32143 mcg
250 lb(113 kg)	6054 mcg	21188 mcg	36321 mcg

💉 For exact syringe units based on your vial concentration, use the Leuprorelin Reconstitution Calculator →

Administration

Route

IM or SC depot injection

Timing

As prescribed (1-6 month intervals).

Fasting Required?

No — food timing not critical

Expected Timeline

Week 1-2

Initial flare of LH/FSH and downstream hormones. Risk of tumor flare.

Week 3-4+

Profound receptor downregulation. Castrate levels of testosterone/estrogen achieved.

Who Is It For?

Hormone-Responsive Cancer

High

Standard of care for androgen-deprivation therapy in prostate cancer.

Endometriosis

High

Creates temporary menopausal state to starve endometriotic tissue of estrogen.

Safety & Considerations

FDA-approved (Lupron). Causes medical menopause/andropause. Side effects include hot flashes, bone density loss, mood changes, and loss of libido. Long-term use requires bone density monitoring.

Regulatory & Legal Status

FDA Status (US)

Research Only

WADA Status (2026)

Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change — verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Interactions & Contraindications

Anti-androgens co-administered during first 2-4 weeks to prevent flare. May reduce efficacy of some antidiabetic agents due to metabolic changes. Monitor bone density with prolonged use.

Synergies & Common Stacks

+ Gonadorelin →

Leuprorelin is a synthetic super-agonist of endogenous GnRH (gonadorelin). They share the same receptor but leuprorelin produces sustained downregulation rather than pulsatile stimulation.

Dosing Quick Reference

Leuprorelin— Dosing Guide

Dose Range

3.75-22.5 mg depot (monthly-quarterly)

Half-Life

3 hours

Frequency

Monthly or every 3-6 months (depot)

Route

Oral

Clinical / Pharmaceuticalcalcmypeptide.com

Frequently Asked Questions

Why does an agonist lower testosterone?▼

Because the pituitary glands expect GnRH in brief pulses. A continuous agonist overwhelms the receptors, causing them to rapidly downregulate (turn off), halting the entire hormone production chain below it.

References

Plosker GL, Brogden RN “"Leuprolide acetate: a review of its pharmacology".” Drugs (1994). PMID: 7515082

Looking for a trusted source? See our recommended suppliers →

Independently tested · COA-verified · Save 10% with our exclusive code

← Back to Peptide Library