Leuprolide vs Triptorelin
A powerful GnRH agonist that helps manage hormone-sensitive conditions by controlling hormone production.
GnRH agonist that helps manage prostate cancer, endometriosis, and early puberty by controlling sex hormones
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
Leuprolide
1–1 mg
Triptorelin
11.25–11.25 mg
Frequency
Leuprolide
Once daily
Triptorelin
Once daily
Administration
Leuprolide
Subcutaneous injection (daily)
Triptorelin
Intramuscular injection
Cycle length
Leuprolide
Ongoing/indefinite
Triptorelin
Ongoing/indefinite
Onset speed
Leuprolide
Moderate (1-2 weeks)
Triptorelin
Moderate (1-2 weeks)
Evidence level
Leuprolide
Strong human trials (Phase 3 or FDA approved)
Triptorelin
Strong human trials (Phase 3 or FDA approved)
Benefit ratings
Cancer Management
Endometriosis & Fibroid Relief
Hormone Control
Hormone Regulation
Endometriosis Relief
Compound specifications
Leuprolide
Molecular formula
C59H84N16O12
Molecular weight
1209.4 g/mol
Half-life
Approximately 2-6 hours (varies by route of administration)
Bioavailability
~95% (subcutaneous injection)
CAS number
74381-53-6
Triptorelin
Molecular formula
C64H82N18O13
Molecular weight
1311.4 g/mol
Half-life
2-3 hours (free peptide); 2-4 weeks (depot pamoate formulations)
Bioavailability
~100% (intramuscular/subcutaneous injection)
CAS number
57773-63-4
Dosing compared
Leuprolide
Subcutaneous
1 mg
Once daily · Ongoing
The original daily form is a 1 mg shot under the skin each day for advanced prostate cancer. It works but needs a shot every day, so most people now use the longer-acting depot instead [4].
Intramuscular
7.5 mg
Every month · Ongoing
The 1-month depot is a single 7.5 mg shot into the muscle every 4 weeks. One injection replaces a month of daily shots [5].
22.5 mg
Every 3 months · Ongoing
The 3-month depot is a 22.5 mg muscle injection given once every 3 months, so fewer office visits [5].
30-45 mg
Every 4-6 months · Ongoing
The longest-acting depots: 30 mg every 4 months, or 45 mg every 6 months. These need only 2-3 injections per year [5].
Triptorelin
Intramuscular injection
3.75 mg
Once every 4 weeks · Ongoing while indicated
FDA-labeled 1-month depot (Trelstar) for advanced prostate cancer; single IM injection into either buttock [5].
11.25 mg
Once every 12 weeks · Ongoing while indicated
FDA-labeled 3-month depot (Trelstar). Strengths are not additive; chosen by desired interval [5].
22.5 mg
Once every 24 weeks · Ongoing while indicated
FDA-labeled 6-month depot (Trelstar for prostate cancer; Triptodur 22.5 mg for central precocious puberty, ages 2+) [5][6].
Best suited for
Leuprolide
Managing advanced or metastatic prostate cancer
Leuprolide is particularly well-suited for individuals focused on managing advanced or metastatic prostate cancer. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach [1][5].
Controlling severe endometriosis pain
Leuprolide is particularly well-suited for individuals focused on controlling severe endometriosis pain. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach [1].
Treating symptomatic uterine fibroids
Leuprolide is particularly well-suited for individuals focused on treating symptomatic uterine fibroids. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach [1].
Delaying early puberty in children
Leuprolide is particularly well-suited for individuals focused on delaying early puberty in children. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach [1].
Triptorelin
Managing advanced prostate cancer when combined with other treatments
Triptorelin is particularly well-suited for individuals focused on managing advanced prostate cancer when combined with other treatments. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Relieving severe endometriosis pain and symptoms
Triptorelin is particularly well-suited for individuals focused on relieving severe endometriosis pain and symptoms. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Delaying puberty development in children with early sexual maturation
Triptorelin is particularly well-suited for individuals focused on delaying puberty development in children with early sexual maturation. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Side effects
Leuprolide
Common
- Hot flashes (very common in men)
- Decreased libido and erectile dysfunction
- Injection site pain or swelling
- Nausea
- Fatigue
- Mood changes or depression
- Joint or muscle pain
- Headaches
- Dizziness
- Thinning hair
- Decreased bone density (osteoporosis with long-term use)
- QT prolongation (rare but serious cardiac effect)
- Tumor flare (temporary worsening of cancer symptoms in first weeks)
- Severe allergic reactions
- Spinal cord compression risk in men with metastatic disease
Serious
- Severe allergic reaction
Triptorelin
Safety & evidence
Leuprolide
Evidence level
Strong human trials (Phase 3 or FDA approved)
FDA status
FDA approved for this use
Safety overview
Leuprolide (Lupron) is an FDA-approved GnRH agonist with 35+ years of clinical safety data involving millions of patients in oncology and endocrinology. [1] The critical safety issue is the initial 5-7 day flare effect—temporary surge in FSH/LH causing symptom worsening before hormone suppression begins—particularly dangerous for prostate cancer patients (flare can cause urinary obstruction or spinal cord compression). [5] Bone density loss is a dose-dependent long-term risk in both men and women requiring monitoring. [1][5] Injection site reactions, hot flushes, and initial hypogonadal symptoms are expected and typically transient. [5]
Contraindications
- Pregnancy or breastfeeding (teratogenic)
- Undiagnosed vaginal bleeding
- Active bone metastases with spinal cord compression (increased fracture risk)
- Allergy to GnRH agonists or components
- Severe cardiovascular disease with QT prolongation risk
Triptorelin
Evidence level
Strong human trials (Phase 3 or FDA approved)
FDA status
FDA approved for this use
Safety overview
Triptorelin (GnRH agonist) has extensive FDA-approved safety data spanning decades for prostate cancer, endometriosis, and precocious puberty indications. Initial testosterone surge upon initiation ("flare reaction") can worsen prostate cancer or spinal cord compression symptoms, requiring careful patient monitoring in first 1-2 weeks and use of androgen antagonists in high-risk patients. Hypogonadal effects including hot flashes, sexual dysfunction, and bone loss develop predictably with chronic GnRH suppression; bone density monitoring is recommended in patients on therapy >6 months.
Contraindications
- Pregnancy (can affect fetal development)
- Undiagnosed vaginal bleeding
- Known hypersensitivity to GnRH agonists
- Severe untreated depression
- Active spinal cord compression in prostate cancer (requires urgent decompression)
Which is right for you?
Choose Leuprolide if...
- Managing advanced or metastatic prostate cancer
- Controlling severe endometriosis pain
- Treating symptomatic uterine fibroids
- Delaying early puberty in children
Choose Triptorelin if...
- Managing advanced prostate cancer when combined with other treatments
- Relieving severe endometriosis pain and symptoms
- Delaying puberty development in children with early sexual maturation