Scientific context only. Not medical advice, not a recommendation to use.
At a glance
Synthetic decapeptide GnRH agonist with increased affinity over native gonadotropin-releasing hormone. FDA- and EMA-approved since the 1980s for prostate cancer, endometriosis and precocious puberty.
Triptorelin binds with high affinity to the GnRH receptor in the pituitary. After initial stimulation of LH and FSH secretion (flare phase, about 1-2 weeks), receptor desensitisation follows with consecutive gonadotropin suppression. This results in a reversible chemical castration: in men testosterone, in women oestrogen suppression to the postmenopausal range.
02
Evidence at a glance
Reading note. The distribution shows on which evidence tier each observation sits. Strong colours mark stronger evidence — weaker tiers are deliberately visible, not hidden.
3 observations · 2 tiers
Human RCT
2
Human trial
1
03
What the studies show
Human RCT
Mensch
Heyns CF. et al. 2003
Suppression of testosterone into the castration range (<50 ng/dL) within 4 weeks in men with prostate cancer documented
What does NOT follow: Reversible after discontinuation; flare phase in the first weeks can cause transient symptom worsening — anti-androgen combination is standard.
Human RCT
Mensch
Reduction of endometriosis pain and lesion size demonstrated versus placebo in randomised trials
What does NOT follow: Effect during therapy; recurrence common after discontinuation. Add-back therapy to mitigate hypo-oestrogenism symptoms is discussed in the literature.
Human trial
Mensch (pädiatrisch)
Suppression of precocious puberty and slowing of bone age in paediatric patients with central CPP documented
What does NOT follow: Long-term effects on final height and bone density are discussed controversially in paediatrics.
05
Pharmacokinetics
Theoretical concentration curve at a half-life of 3 h. Pure pharmacokinetic model — not a dosing recommendation.
Which routes of administration the available studies describe — neutral reporting, not a usage guide.
Intramuscular
In the registration trials administered as depot microspheres intramuscularly (gluteal or deltoid) every 1, 3 or 6 months.
Subcutaneous
For some formulations subcutaneous administration is approved as an alternative.
07
Known adverse events from studies
Factual reporting of what studies observed. Not a safety statement for individual use.
Human RCT
Hot flashes
Most frequent class-effect event in men and women under GnRH agonist therapy.
sehr häufig
Human RCT
Bone mineral density reduction with long-term therapy
Bone mineral density monitoring and possibly bisphosphonates are recommended in oncology guidelines.
bei mehrjähriger Anwendung
Human RCT
Flare reaction in the first 2 weeks
Anti-androgen pretreatment is standard before initiation in metastatic prostate cancer to avoid spinal-compression symptoms.
vorhersagbar
07b
Interactions & combinations
Documented interactions and contraindications from studies, prescribing information and guidelines. Where no data exists, this is stated.
Reporting of risks, NOT a combination guide. The absence of an entry does not mean „safe to combine“ but „not sufficiently studied“.
No documented interactions recorded
We have not yet found robustly documented interactions for this peptide. This does NOT mean none exist — the data is limited.
09
Regulatory voices
Direct statements from official assessment documents — paraphrased with date and source link.
FDAU.S. Food and Drug Administration
2010-04-01
FDA press release on the approval of the Trelstar 6-month depot.
Trelstar provides an effective option for hormonal suppression therapy in advanced prostate cancer — the 6-month formulation reduces treatment frequency to two injections per year.
FDA-approved as Trelstar (1, 3 and 6-month depot) for advanced prostate cancer. Prescription-only.
2026-05-22
Germany
Prescription
Approved in Germany as Decapeptyl in multiple depot formulations since the 1980s. Prescription-only.
2026-05-22
12
Reconstitution calculator
Pure mg/mL maths — works like a calculator. Not a usage recommendation.
Peptides ship as a dry powder. Once dissolved in a liquid (reconstitution), this calculator answers a single question: how much substance is in one millilitre of solution afterwards?
1Enter the vial's substance amount (printed on the label).
2Enter how much solvent you add.
3Result = concentration in mg per mL.
Printed on the label
/
Liquid you add
=
2.50
mg / mL
5 mg in 2 mL gives 2.50 mg/mL — each millilitre contains 2.50 mg of substance.
14
Study register
Human RCTRandomised controlled trialn = 284
Heyns CF. et al. · 2003
Comparative efficacy of triptorelin pamoate and leuprolide acetate in men with advanced prostate cancer
Concrete results
Proportion with testosterone in castration range (week 9)