OnePin Peptide Library · Hormonal
Triptorelin
Decapeptyl · Trelstar · Diphereline · Gonapeptyl
Triptorelin is a synthetic decapeptide analog of gonadotropin-releasing hormone (GnRH), also known as luteinizing hormone-releasing hormone (LHRH). It differs from native GnRH by substitution of D-tryptophan at position 6, which makes it resistant to enzymatic degradation and significantly more potent than endogenous GnRH. Brand names include Trelstar, Decapeptyl, and Diphereline.,Triptorelin works through a biphasic mechanism. Initial administration causes a brief surge in LH, FSH, and downstream sex hormones (the 'flare' effect). With continuous or repeated depot administration, it downregulates GnRH receptors on pituitary gonadotropes, leading to profound suppression of LH and FSH secretion and consequently reducing testosterone and estradiol to castrate or prepubertal levels.,Triptorelin is FDA-approved for the palliative treatment of advanced prostate cancer (Trelstar depot formulations) and for central precocious puberty. It is also widely used in Europe for endometriosis, uterine fibroids, and assisted reproduction protocols. In off-label contexts, a single low-dose injection (typically 100 mcg) has been used for post-cycle therapy (PCT) in the bodybuilding community to restart the hypothalamic-pituitary-gonadal (HPG) axis after anabolic steroid use.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
How it works
Acts as a GnRH superagonist with 100x greater potency than native GnRH. Initial binding to pituitary GnRH receptors causes a transient 'flare' of LH and FSH release (days 1-7), temporarily increasing sex hormone levels.,Continuous or depot administration causes GnRH receptor downregulation and desensitization of pituitary gonadotropes, leading to profound suppression of LH and FSH. This results in medical castration with testosterone falling to <50 ng/dL (prostate cancer) or estradiol to prepubertal levels.,Low single-dose use (PCT context): A single 50-100 mcg dose is proposed to cause a strong but transient LH/FSH surge without sustained suppression, theoretically kickstarting endogenous testosterone production after exogenous androgen use.
Acts as a GnRH superagonist with 100x greater potency than native GnRH. Initial binding to pituitary GnRH receptors causes a transient 'flare' of LH and FSH release (days 1-7), temporarily increasing sex hormone levels.,Continuous or depot administration causes GnRH receptor downregulation and desensitization of pituitary gonadotropes, leading to profound suppression of LH and FSH. This results in medical castration with testosterone falling to <50 ng/dL (prostate cancer) or estradiol to prepubertal levels.,Low single-dose use (PCT context): A single 50-100 mcg dose is proposed to cause a strong but transient LH/FSH surge without sustained suppression, theoretically kickstarting endogenous testosterone production after exogenous androgen use.
What to expect
Days 1-7: LH/FSH flare with transient increase in sex hormones. For PCT, this surge is the intended therapeutic effect. For cancer treatment, anti-androgen cover may be needed.
Evidence
Interactions & stacking
What's safe to combine, and what belongs in a separate pin.
Safe & synergistic
Keep separate
Pharmacokinetics
Storage. Store refrigerated at 2-8C. Depot formulations: follow specific product instructions. Reconstituted non-depot solution should be used immediately.
Regulatory status
FDA-approved (Trelstar) for advanced prostate cancer and central precocious puberty. EMA-approved (Decapeptyl/Diphereline) for additional indications including endometriosis and IVF. Prescription only.
Put it to work
Calculate, log & track
Open Triptorelin straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.
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The guide & community
The complete Triptorelin walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.
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