Triptorelin

Status FDA-approved (Trelstar, Triptodur) for advanced prostate cancer and central precocious puberty; approved in other jurisdictions for endometriosis and uterine fibroidsBest evidence E1Sources checked 2026-09-18

Triptorelin is an FDA-approved GnRH agonist (Trelstar, Decapeptyl, Triptodur) used to suppress sex hormone production for prostate cancer and central precocious puberty, with decades of Phase 3 evidence. Its approved mechanism is hormone suppression, not optimization, and it has no approved or trial-supported general wellness use.

What it is

Triptorelin is a synthetic GnRH agonist, a modified decapeptide analogue of native GnRH engineered for much greater potency and a longer duration of action than gonadorelin. Rather than stimulating the reproductive axis the way pulsatile native GnRH does, sustained triptorelin exposure downregulates and desensitizes pituitary GnRH receptors, producing a profound, reversible suppression of LH, FSH and downstream sex steroids after an initial transient stimulation (“flare”) in the first one to two weeks of treatment.

It is FDA-approved, sold under brand names including Trelstar, Decapeptyl and Triptodur, for advanced prostate cancer (as a form of medical castration), central precocious puberty in children, and, outside the US, endometriosis and uterine fibroids. It is given as an intramuscular depot injection, in monthly, 3-month or 6-month long-acting formulations depending on the product.

The evidence behind its approvals

Triptorelin’s prostate cancer and precocious puberty indications rest on a substantial body of Phase 3 trial and long-term outcome data spanning decades, evaluating testosterone (or estradiol) suppression to castrate levels, disease-specific outcomes, and safety in each population, and this is one of the more mature evidence bases of any compound on this site.

What is not established for uses outside its approvals

Any use of triptorelin for anti-aging, longevity, or general hormone-optimization purposes, which is how it is sometimes discussed in the research-peptide community. Its approved mechanism is deliberate, sustained suppression of sex hormone production, the pharmacological opposite of a hormone-optimization goal, and no trial reviewed for this entry supports repurposing it that way.

Reversibility timelines and long-term effects when a GnRH agonist like triptorelin is used outside its approved dosing schedule or populations.

What is not known

Any use for anti-aging, longevity or hormone-optimization purposes. Its approved mechanism is sustained suppression of sex hormone production, not optimization, and no trial supports repurposing it that way.

Reversibility timelines and long-term effects when used outside its approved dosing schedule or approved populations.

Doses used in published research

No published study has administered this compound to a human being, so no dose appears in the literature and none has been established.

Amounts above record what a named source reported administering in a study. They are not a recommendation, not a protocol, and not instructions.

Converting a vial and a syringe into a draw volume is a separate, mechanical question from what amount to use. The reconstitution calculator does that arithmetic for peptide, HCG, and HGH vials.

What circulates E5

Figures reported online. Not dosing, not verified, not endorsed.
Reported use	Route	Amount reported	Frequency	Reported length
General hormonal manipulation, non-approved	Intramuscular or subcutaneous	Varies by listing	Varies by listing	Varies by listing

Circulating discussion of triptorelin outside its approved indications describes varying doses for non-approved hormonal-manipulation purposes. The approved dosing (depot IM injection, monthly to 6-monthly, for suppression to castrate hormone levels) was studied for prostate cancer and precocious puberty specifically; no trial reviewed for this entry tested any other regimen for a wellness or optimization purpose, and the drug’s intended effect, suppressing sex hormones, is the opposite of what such use would be seeking.

Recorded as an observation about what is published elsewhere. No figure here is a dose, a protocol, or a recommendation, and nothing in this section is evidence that any amount is safe or effective.