Education only, not medical advice◆21+◆Every dose is an example to finalize with a licensed provider
HormonalFDA-approved medicinePrescription drug
Triptorelin
Decapeptyl · Trelstar · Diphereline · Gonapeptyl
Evidence: Approved label. Example dose: finalize with a provider. Not a fact-check stamp.
100 mcgSubQSingle dose (PCT) or monthly/3-month depot (clinical)
3.75 mg depotIMMonthly (every 28 days)
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.
Quick Start
Route
Intramuscular (IM) or Subcutaneous (SubQ)
Start low
100 mcg SubQ
Frequency
Single dose (PCT) or monthly/3-month depot (clinical)
Timing
No specific requirement
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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.
Tiered Protocols · lowest first
Conservative start
100 mcg · Intramuscular (IM) or Subcutaneous (SubQ) · Single dose (PCT) or monthly/3-month depot (clinical)
conservative starter
100 mcg
Single dose (PCT) or monthly/3-month depot (clinical)
Expert
HPTA Restart Protocol
100 mcg · SubQ · As needed
anecdotal · community
MUST be limited to a single 100mcg shot. Administering multiple doses will chemically castrate the user via pituitary desensitization.
100 mcg
As needed
Research
Depot (Prostate cancer)
3.75 mg depot · IM · Monthly (every 28 days)
human clinical trial · Heidari Bateni et al. 2015 (Nephrourol Mon, PMID 26290848); FDA-approved depot label
3.75 mg depot
Monthly (every 28 days)
Reconstitution CalculatorU-100
050100u
Draw to
— units
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01
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.
02
What to expect
Early
Days 1–7
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.
03
Evidence
HumanPresent
AnimalPresent
In-vitroPresent
Each reference below was re-fetched from its PubMed record, and the quoted sentence was
confirmed to appear in that abstract and to support the claim it sits under. Follow any of
them to read the source.
Exact-molecule evidence boundary: the live abstract reports the quoted finding for Triptorelin; no broader inference is made.
The aims of the study were (i) to compared the efficacy of the two long-acting GnRH agonists (GnRHa) triptorelin (Trp) and leuprolide (Leu) in men with prostate cancer and (ii) to assess the pattern of plasma testosterone levels following each injection of GnRHa.
Evidence scope. Exact molecule wording appears in the quoted live sentence. Only the population/model, formulation, route, and outcome expressly stated there are supported.
Claims we could not support
No abstract we checked supports these for this molecule at this route. That is not the
same as saying they are false — it marks where the evidence is missing.
Dose/route: 100 mcg; Intramuscular (IM) or Subcutaneous (SubQ); Single dose (PCT) or monthly/3-month depot (clinical). No selected live abstract sentence verified this complete regimen.
Mechanism as written in source JSON. No selected live abstract sentence verified the complete mechanism at the card formulation/route and relevant population/model.
Primary safety claim as written in source JSON. No selected live abstract sentence verified the complete safety claim for this exact formulation and route.
04
Interactions & stacking
Two different questions: what is documented about running these together, and what is documented about drawing them into the same syringe. A good pharmacological partner can still have to be pinned separately.
Documented together
BPC-157Tissue repair peptide does not interact with GnRH signaling
Thymosin Alpha-1Immune peptide and GnRH agonist act through entirely unrelated systems
AnastrozoleAI can manage estrogen during the initial testosterone flare from triptorelin
EnclomipheneFor PCT use - triptorelin single dose provides initial LH/FSH surge, followed by enclomiphene to sustain endogenous testosterone recovery
Keep separate
Nandrolone DecanoateExogenous anabolic steroids suppress the HPG axis that triptorelin aims to modulate - do not use concurrently
Testosterone CypionateExogenous testosterone suppresses LH/FSH, negating the purpose of GnRH agonist therapy for axis recovery
GnRH (Gonadorelin)Both act on GnRH receptors - co-administration causes unpredictable receptor dynamics and desensitization
KisspeptinKisspeptin stimulates endogenous GnRH release while triptorelin acts as a GnRH superagonist - overlapping and potentially conflicting HPG axis stimulation
Check any specific pair in the Stack & Interaction Checker, which answers both questions separately. Absence of a documented conflict is not evidence of safety.
05
Pharmacokinetics
Illustrative plasma concentration · 18 h
Half-life
~3-5 hours
(non-depot); depot formulations provide sustained release over 1-6 months
Peak · Tmax
1-3 hours
IM/SubQ (non-depot); depot release peaks vary by formulation
Elimination
~15-25 hours
(non-depot); depot formulations sustain levels for 1-6 months
Storage. Store refrigerated at 2-8C. Depot formulations: follow specific product instructions. Reconstituted non-depot solution should be used immediately.
06
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.