Clinical / Pharmaceutical

Leuprorelin

Leuprolide · Lupron · Eligard · GnRH agonist

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.

Not FDA-approved - research chemical
Reviewed by CalcMyPeptide Editorial Team
Last updated: August 2026Evidence: High1 peer-reviewed citation
Typical research dose
3.75-22.5 mg depot (monthly-quarterly)
Frequency
Monthly or every 3-6 months (depot)
Half-life
~3 hours (but formulated as depot depot for 1-6 months)
Common vials
N/A (oral)
CAS
53714-56-0
Molecular weight
1209.4 g/mol

Use-case scores

0–10 against the evidence we have, not a gym ranking. Hidden domains do not apply here.

  • Sexual / hormonal3/10

    Real drug. Wrong tool for “peptide TRT.” Flare then suppression. Not gonadorelin pulse therapy.

Compound card

Class
GnRH agonist depot (Lupron; labeled oncology/endometriosis/precocious puberty)
Formula
C59H84N16O12
Status
Not FDA-approved · research use

How it works

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

PhaseDoseFrequencyNotes
Oncology / Endometriosis3.75 - 22.5 mg DepotMonthly, 3-month, or 6-month injectionsGiven strictly under medical supervision. Typically mixed into polymer microspheres for slow release.

Administration

Route / form
IM or SC depot injection
Timing
As prescribed (1-6 month intervals).
Empty stomach?
No - Food timing is not critical.

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 it is 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.

Limits of current evidence

  • This site will not treat prostate cancer or endometriosis from a peptide page.
  • Not triptorelin, not gonadorelin, not kisspeptin.

Verdict

Leuprolide is Lupron. Depot GnRH agonist. It is not a fertility peptide and not a testosterone secretagogue for bro science. Flare-then-castrate is the point of the oncology label.

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.

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

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

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