GnRH agonist approved for prostate cancer and early puberty; a single small dose is used off-label to trigger ovulation in IVF.
Also called Trelstar, Triptodur, Decapeptyl, Gonapeptyl, Gonapeptyl Daily, Triptorelin pamoate, Triptorelin acetate, D-Trp6-LHRH
When Triptorelin's status or evidence changes, it's in the next morning's email.
Triptorelin is a 10-amino-acid copy of GnRH, the brain hormone that tells the pituitary to release LH and FSH. Swapping one amino acid for D-tryptophan makes it far more potent and longer-lasting than natural GnRH. Like leuprolide, it works in two phases: one dose releases a burst of LH and FSH, while steady dosing shuts the pituitary down and drives testosterone or estrogen to very low levels.
In the US, Trelstar depots (every 4, 12 or 24 weeks) are approved for advanced prostate cancer, and Triptodur (every 24 weeks) for central precocious puberty in children 2 and older. In Europe, a 0.1 mg daily injection sold as Decapeptyl or Gonapeptyl is authorised to keep the pituitary quiet during IVF stimulation. IVF clinics also give a single 0.1 to 0.4 mg dose off-label to trigger final egg maturation instead of hCG; in a 131-woman study, 0.1 mg matured eggs as well as 0.2 or 0.4 mg.
Some bodybuilders search for triptorelin as a one-shot way to restart testosterone after a steroid cycle. No published trial has tested that. What studies do show is a short LH and testosterone rise after a dose, and suppression when dosing continues. WADA bans triptorelin in male athletes, and a 2025 study found a triptorelin breakdown product in urine that anti-doping labs can test for.
What it binds to, and what happens inside the body after that, step by step.
Triptorelin binds GnRH receptors on the pituitary. A single dose releases LH and FSH, and in women at the end of IVF stimulation that LH surge finishes egg maturation, the way a natural mid-cycle surge does. Continuous exposure desensitizes the receptors, so LH, FSH and sex hormones fall to castrate or prepubertal levels; this is how the depots treat prostate cancer and early puberty.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
Triptorelin is an approved drug: Trelstar's label trials show castrate testosterone by day 29 in 91% to 98% of men, and Triptodur suppressed early puberty in at least 93% of 44 children. Its use as an IVF trigger rests on the GnRH agonist trigger trials and Cochrane review plus smaller dose studies, including a retrospective study of 131 women that found 0.1 mg as effective as 0.2 or 0.4 mg. Its use for testosterone recovery after steroids has no published human trial.
131 women at high risk of OHSS having ICSI with an antagonist protocol, retrospective
Egg maturation rates were 82.6%, 83.3% and 85.1% after 0.1, 0.2 and 0.4 mg triptorelin, with no significant difference.
Read the study17 RCTs, 1,847 women in IVF/ICSI
A GnRH agonist trigger cut OHSS (odds ratio 0.15) but lowered live birth in fresh transfers (odds ratio 0.47).
Read the study9 women given 0.1 mg triptorelin, compared with 14 matched women given 0.2 mg
Mature egg numbers and pregnancy rates did not differ between 0.1 mg and 0.2 mg, and no woman developed OHSS.
Read the studyEgg donors, each stimulated twice (hCG trigger, then triptorelin trigger)
Triptorelin 0.2 mg gave the same number of mature eggs as hCG (13.0 vs 12.6); one donor needed treatment for OHSS after hCG.
Read the study6 men aged 18 to 34 with hypothalamic hypogonadism, 6 months
10 mcg every other day raised the LH response at 1 month, but by 6 months it was back at baseline; the authors called this a paradoxical inhibitory response, probably from too high a dose.
Read the study5 men with prostate cancer starting triptorelin, compared with leuprorelin
Triptorelin suppressed LH and testosterone more than leuprorelin, and its breakdown product triptorelin (5-10) was found in urine and blood.
Read the studyNo preclinical studies are listed as key studies here. The human data above carries the evidence.
When a new Triptorelin study in people is published, the daily email covers it.
These are questions the published research has not answered.
In the US, triptorelin's IVF uses (daily pituitary suppression and the single-dose trigger) are off-label; in the EU, the 0.1 mg daily injection is authorised for down-regulation during IVF. The Trelstar label warns of tumor flare, diabetes, heart attack and stroke, QT prolongation, seizures and severe skin reactions. WADA's 2026 list names triptorelin under S2.2.1, testosterone-stimulating peptides prohibited in males at all times.
When the FDA or WADA changes Triptorelin's status, it's in the next morning's email.
How much of Triptorelin is left after a single dose
Simple first-order model from the published half-life. Real clearance varies with dose, route, kidney and liver function and formulation. This is not a dosing schedule.
This table records the doses that trials and approved labels used, with the source for each row. It is a record of research, not a recommendation, and it is open to free members.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
No published trial has given triptorelin to men coming off anabolic steroids. A dose does release LH briefly, but in 6 men given it every other day the LH response faded by 6 months, and continuous dosing is how the drug shuts testosterone down in prostate cancer.
In 131 high-risk women, maturation rates were 82.6% with 0.1 mg vs 83.3% and 85.1% with 0.2 and 0.4 mg. That was a retrospective study, not a randomized trial.
Agonist triggers sharply cut OHSS, but a Cochrane review found fewer live births when embryos are transferred fresh in the same cycle. The review authors suggest it for egg freezing, egg donors and freeze-all cycles, and the live-birth gap was seen mainly when luteal support had no LH activity.
WADA lists it by name, and a 2025 study confirmed triptorelin (5-10), a breakdown product found in urine and blood, as a marker labs can test for.
These pairings come up often. Almost none have been tested together in a trial, and the evidence note on each says so plainly.
A GnRH antagonist blocks early ovulation during stimulation without taking the pituitary offline, so a single triptorelin dose can still release an LH surge to mature the eggs.
EvidenceSupported by the Cochrane review of 17 RCTs on agonist triggers: much less OHSS, fewer live births in fresh transfers. Off-label in the US.
Promoted online as a single injection to restart LH and testosterone after anabolic steroids.
EvidenceUntested. No study in men coming off steroids; continued dosing suppresses the pituitary, and WADA bans it in males.
Trelstar and Triptodur kits: 20 to 25°C (68 to 77°F); do not freeze.
Trelstar must be injected within 2 minutes of mixing; Triptodur settles fast and must be injected immediately after mixing.
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