Hormones & Fertility

Triptorelin

Trelstar · Decapeptyl · long-acting GnRH agonist

cautionnichesubQ / IM injection

What it is

Triptorelin is a long-acting GnRH agonist. FDA-approved for advanced prostate cancer and central precocious puberty. In the bodybuilding/biohacker community, it's used as a "single-shot" HPG axis reset to restart natural testosterone production after a steroid cycle.

How it works

Initially causes a strong burst of LH/FSH/testosterone (the "flare effect"), then with continuous receptor occupation downregulates GnRH receptors, suppressing the entire HPG axis. After clearance, the axis resets and natural production resumes. The "single-shot reset" use is off-label and controversial.

Benefits

HPG axis "restart" after long steroid cycles (off-label)
Initial testosterone surge
Used clinically for prostate cancer (induces medical castration)
Used in fertility treatment for ovulation induction

Timeline

Day 1–3: Massive testosterone surge ("flare").
Week 1–2: HPG axis suppression starts (clinical use).
Week 4–6 (after single-shot): Natural production resumes after clearance.

Dosing & titration

Single-shot reset100 mcg subQ once (PCT use)

Clinical depot3.75 mg IM once monthly (cancer)

When to titrate upDon't — this is a one-shot tool in PCT contexts. Frequent dosing causes prolonged HPG suppression.

Side effects & risks

Initial testosterone surge can cause acne, mood changes
Subsequent suppression can cause hot flashes, low libido temporarily
Headaches, injection site reactions
Long-term: bone density loss with repeated use (clinical context)

Off-label PCT use is controversial. Clinical use is for medical castration in prostate cancer. The single-shot reset hasn't been validated in clinical trials.

Typical price

$80–$200 per shot100 mcg dose from compounding source. Branded depot is far more expensive.

Studies

Klotz L et al. The efficacy and safety of degarelix versus triptorelin in patients with prostate cancer — Clinical comparison. PubMedTherapeutic Advances in Urology, 2008
Search PubMed for triptorelin — PubMed searchLive PubMed search

Educational reference only. Not medical advice.