Leuprolide
Also known as: Leuprorelin, Lupron, GnRH Agonist
Overview
Leuprolide is a synthetic nonapeptide analog of gonadotropin-releasing hormone (GnRH) with approximately 80-fold greater potency than the natural hormone. Paradoxically, continuous (non-pulsatile) administration causes GnRH receptor downregulation, leading to profound suppression of LH, FSH, and downstream sex hormones. This mechanism is exploited therapeutically for prostate cancer, endometriosis, uterine fibroids, precocious puberty, and as part of gender-affirming hormone therapy protocols.
Mechanism of Action
Leuprolide initially stimulates GnRH receptors on pituitary gonadotrophs (flare effect), transiently increasing LH and FSH. With continuous exposure, receptor desensitization and downregulation occur within 2-4 weeks, causing sustained suppression of gonadotropin secretion. Testosterone and estradiol fall to castrate levels. The flare effect can be clinically significant in prostate cancer (tumor flare) and is managed with antiandrogen co-administration.
Potential Benefits
- Medical castration for androgen-sensitive prostate cancer
- Endometriosis and uterine fibroid symptom control
- Treatment of central precocious puberty
- Component of gender-affirming protocols
- Fertility treatment (controlled ovarian stimulation protocols)
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Beginner | 1 mg SC daily (daily formulation) |
| Intermediate | 7.5 mg IM monthly depot (prostate cancer) |
| Advanced | 22.5 mg every 3 months or 45 mg every 6 months (depot formulations) |
| Cycle Duration | Months to years (depending on indication) |
FDA-approved (Lupron, Eligard). Causes initial testosterone surge ('flare') before suppression. Used for prostate cancer, endometriosis, central precocious puberty, IVF.
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Subcutaneous Injection (daily) ~94%
Lupron 1 mg/0.2 mL daily formulation.
Intramuscular/Subcutaneous Depot Sustained release
Lupron Depot 7.5/22.5/30/45 mg every 1/3/4/6 months respectively.
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Stacking Protocols
Popular research stacks involving Leuprolide:
Prostate Cancer ADT
Combined androgen blockade — leuprolide suppresses LH/testosterone while bicalutamide blocks androgen receptor.
Explore our complete Peptide Stacking Guide for more combinations and safety considerations.
Reconstitution
| Storage | Store at room temperature 15-30°C. Protect from light. Once mixed, depot must be used immediately. |
|---|
Depot formulations use proprietary microsphere technology — follow kit instructions exactly.
Need exact syringe measurements?
Amino Acid Sequence
pyroGlu-His-Trp-Ser-Tyr-D-Leu-Leu-Arg-Pro-NHEt
Side Effects & Safety
- Hot flashes
- Sexual dysfunction (low libido, erectile dysfunction)
- Bone density loss with long-term use
- Initial tumor flare in prostate cancer
- Mood changes, depression
Safety & Contraindications
This information is for educational purposes only. Consult a qualified healthcare provider before using any peptide.
Hormone-Sensitive Cancers
Pregnancy / Lactation
Bleeding Disorders
Active Skin Infection at Injection Site
Drug Interactions
- QT-Prolonging Agents:
FDA Safety Information
FDA labeling warns of transient tumor flare, decreased bone density with long-term use, cardiovascular risk, QT prolongation, and convulsions.
Pharmacokinetics
| Half-Life | ~3 hours (parent drug); depot formulations provide sustained release over weeks-months |
|---|---|
| Storage | Store at controlled room temperature 15-30°C. Protect from light. Do not freeze. |
Synergistic Compounds
The following compounds have been studied alongside Leuprolide for potential complementary or synergistic effects:
Learn More
References & Further Reading
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