Triptorelin

What it is

Triptorelin is a synthetic GnRH agonist derived from native GnRH by substitution of a D-amino acid (D-tryptophan) at position 6, which increases resistance to enzymatic breakdown and affinity for LH-RH receptors, producing a superagonistic effect. Initial administration stimulates luteinizing hormone (LH) and testosterone secretion (the "flare-up"), followed by downregulation of pituitary GnRH receptors and sustained suppression of LH, FSH, and gonadal sex steroids (PMID 39757119, PMID 16302716, PMID 47). Sustained suppression is achieved through a decrease in receptor synthesis. The biological half-life after subcutaneous injection is approximately 10 times greater than after intravenous injection due to progressive release from the injection site. Triptorelin also binds to LH-RH receptors overexpressed on certain cancer cells (e.g., triple-negative breast cancer, GnRH-positive breast cancer), providing a basis for targeted drug delivery applications (PMID 35929297, PMID 26458110, PMID 34104122).

Class: Gonadotropin-releasing hormone (GnRH) agonist / LH-RH superagonist (synthetic decapeptide)

What it's studied for

• Central precocious puberty (CPP) in children Human RCT
  • Phase 3 open-label study in 66 Chinese children with CPP: two doses of triptorelin pamoate 22.5 mg (day 1 and month 6) achieved LH suppression (stimulated peak LH ≤5 IU/L) in 100% at month 6, maintained in 98.5% at month 12; 19.7% had drug-related TEAEs, no grade ≥3 TEAEs. PMID 39412628 Yu X et al., Advances in Therapy (2024)
  • Multicenter open-label 12-month trial in 64 children (54 girls, 10 boys): triptorelin 11.25 mg every 3 months achieved GnRH-stimulated peak LH ≤3 IU/L in 85%, 97%, and 95% at months 3, 6, and 12 respectively; well tolerated with only one instance of severe injection pain. PMID 16382000 Carel JC et al., European Journal of Endocrinology (2006)
  • Meta-analysis of 153 children with CPP treated with triptorelin 11.25 mg 3-month formulation: suppressed LH response (peak ≤3 IU/L) in 87.6% at 3 months and 92.8% at 6 months. PMID 28334719 Durand A et al., Hormone Research in Paediatrics (2017)
  • International phase III study: triptorelin 6-month formulation (22.5 mg im, twice at 24-week interval) in 44 CPP patients showed 93.2% with prepubertal LH levels at month 6, reaching 97.7% at month 12; no unexpected drug-related adverse events. PMID 26887034 Klein K et al., Journal of Pediatric Endocrinology & Metabolism (2016)
  • Retrospective study in 82 girls with CPP: triptorelin combined with rhGH showed significantly higher height and body mass, lower BA/CA ratio, lower sex hormone levels, and 97.50% effective treatment rate vs 80.95% for triptorelin alone at 1 year; no serious adverse reactions in either group. PMID 39998154 Lao X et al., British Journal of Hospital Medicine (2025)
  • 42 patients with idiopathic CPP treated with 6-month triptorelin formulation for ≥12 months: basal LH suppressed to <1.0 IU/L, LH/FSH ratio <0.66, bone age/chronological age ratio decreased from 1.15 to 1.11 at 18 months; no adverse effects observed during treatment. PMID 36875449 Yoo E et al., Frontiers in Endocrinology (2023)
  • 20 CPP patients treated with triptorelin 11.25 mg every 90 days for 2 years: all patients had GnRH-stimulated peak below 3 mIU/mL between 6 and 24 months; pituitary-gonadal axis recovered adequately after discontinuation. PMID 16995580 Martínez-Aguayo A et al., Journal of Pediatric Endocrinology & Metabolism (2006)
• Advanced / metastatic prostate cancer (androgen deprivation therapy) Human RCT
  • Randomized controlled trial in 284 men: triptorelin 3.75 mg vs leuprolide 7.5 mg IM every 28 days for 9 injections. Triptorelin reached castrate testosterone more slowly at day 29 (91.2% vs 99.3%) but maintained castration equivalently. 9-month survival rate was significantly higher for triptorelin (97.0% vs 90.5%, P=0 PMID 12887472 Heyns CF et al., BJU International (2003)
  • Phase III open-label study in 120 patients with advanced prostate cancer: triptorelin embonate 22.5 mg IM twice at 24-week interval achieved castrate testosterone in 97.5% by day 29 and maintained castration in 93.0% at months 2-12; most common drug-related adverse event was hot flushes (71.7%). PMID 19888782 Lundström EA et al., Clinical Drug Investigation (2009)
  • Pooled retrospective analysis of 920 prostate cancer patients across 9 prospective studies: after 1, 3, 6, 9, and 12 months of triptorelin SR treatment, 79%, 92%, 93%, 90%, and 91% of patients reached testosterone <20 ng/dL, respectively. PMID 28028737 Breul J et al., Advances in Therapy (2017)
• Endometriosis (pelvic pain, deep infiltrating endometriosis) Human RCT
  • Phase 3 RCT in 300 Chinese women with endometriosis: triptorelin pamoate 15 mg every 12 weeks (3-month) was noninferior to triptorelin acetate 3.75 mg every 4 weeks (1-month); >98% in both groups had estradiol suppressed to castration levels at week 12; no new safety concerns. PMID 35947347 Li X et al., Advances in Therapy (2022)
  • Prospective non-interventional study in 384 women with deep infiltrating endometriosis treated with triptorelin 3.75 mg every 28 days for up to 24 weeks post-surgery: cumulative improvement rates in pelvic pain 74.4%, dysmenorrhea 83.6%; 24-month cumulative recurrence rate 22.2%; well tolerated without serious adverse PMID 35119037 Zhu L et al., Medicine (2022)
• Hormone receptor-positive early breast cancer (adjuvant ovarian function suppression in premenopausal women) Human RCT
  • Review: triptorelin 1-month formulation (Decapeptyl) approved in EU as adjuvant treatment combined with tamoxifen or aromatase inhibitor in endocrine-responsive early-stage breast cancer in premenopausal women at high risk of recurrence. OFS plus exemestane provided more pronounced disease control than OFS plus tamoxif PMID 29177573 Frampton JE, Drugs (2017)
  • Triptorelin (LH-RHa) is approved by FDA and EMA in combination with tamoxifen or aromatase inhibitor and with fulvestrant and palbociclib in premenopausal women with HR-positive breast cancer. Combination with tamoxifen and exemestane increased endocrine-deprivation symptoms. PMID 31500470 Ferraro E et al., Expert Opinion on Pharmacotherapy (2019)
• Fertility preservation / ovarian function suppression during chemotherapy for breast cancer Human RCT
  • Clinical trials explored LH-RHa (including triptorelin) with chemotherapy for fertility preservation, demonstrating no detrimental effect on patients' oncological outcome. PMID 31500470 Ferraro E et al., Expert Opinion on Pharmacotherapy (2019)
• Assisted reproductive technology (ART) — pituitary downregulation in IVF/ICSI protocols Human observational
  • Retrospective cohort of 3186 IVF/ICSI cycles: depot triptorelin 1.25 mg vs 1.875 mg for pituitary suppression showed no significant difference in live birth rate (41.2% vs 43.7%); lower dose associated with slightly fewer retrieved oocytes. PMID 27072965 Chen X et al., Journal of Huazhong University of Science and Technology (2016)
  • Triptorelin described as 'first-line drug for ART'; low bioavailability and frequent subcutaneous injection impair quality of life; novel silk fibroin microneedle delivery in rats showed prolonged drug half-life, increased relative bioavailability, and surging then prolonged downregulation of LH and estradiol. PMID 37428682 Lu X et al., Drug Delivery (2023)
• Gender dysphoria — puberty suppression in transgender and gender-diverse adolescents Human observational
  • Review: triptorelin used as puberty blocker for transgender and gender-diverse adolescents with GD; effective in reducing psychological distress but accompanied by side effects including slowed growth, increased BMI, and risks to bone health. PMID 41267605 Lacasella G et al., La Clinica Terapeutica (2025)
  • Since 2018, Italian National Committee for Bioethics endorsed off-label use of triptorelin for adolescent GD; concerns persist regarding long-term effects on bone density, brain development, and fertility. PMID 40109078 Lippi M et al., La Clinica Terapeutica (2025)
• Adenomyosis Human RCT
  • Prospective clinical trial: triptorelin acetate 3.75 mg/4 weeks SC injection for 16 weeks vs dienogest 2 mg/day orally in 41 women with adenomyosis. Both reduced pelvic pain significantly; triptorelin was more effective in controlling menorrhagia and reducing uterine volume. PMID 25990480 Fawzy M & Mesbah Y, Archives of Gynecology and Obstetrics (2015)
• Targeted drug delivery / MRI contrast agent for GnRH receptor-positive cancers (investigational/in vitro) In vitro only
  • In vitro/computational study: triptorelin-conjugated PEG-coated biosynthesized gold nanoparticles showed 3–9-fold greater adhesion to TNBC cells than normal breast cells, attributed to LHRH receptor overexpression. PMID 35929297 Uzonwanne VO et al., Biomaterials Advances (2022)
  • In vitro study: SPION@CMD@triptorelin showed 6.5-fold greater cellular uptake in MDA-MB-231 cells vs non-targeted nanoparticles; no cellular cytotoxicity; proposed as T2-weighted MRI probe for GnRH-positive cancer. PMID 34104122 Yousefvand M et al., Contrast Media & Molecular Imaging (2021)
• Short stature associated with premature sexual development (triptorelin ± growth hormone) Human observational
  • 26 children with CPP and short stature treated with triptorelin (4 monotherapy, 22 combination with GH): significant improvements in predicted adult height (PAH) after 1 year; individualized triptorelin-GH combination therapy offered superior height outcomes. PMID 41841385 Yao HB et al., Clinical Endocrinology (2026)

Community-reported dosing

Tier key: Research = PMID-cited study · [C] = scraped community source · [S] = model-synthesized from aggregate community reports (softer evidence). How we source.