Reproductive & hormonal
Triptorelin
A long-acting GnRH agonist approved for prostate cancer, endometriosis and puberty that starts too early.
What it is
Triptorelin is a synthetic decapeptide GnRH agonist with a substitution that makes it more potent and resistant to breakdown. Given continuously as a depot injection, it suppresses pituitary gonadotropin release and with it sex-hormone production. It is licensed across Europe and elsewhere for prostate cancer, endometriosis, central precocious puberty and, in some formulations, female infertility protocols.
How it works
- 1
Activates pituitary GnRH receptors, initially increasing then exhausting LH and FSH release.
- 2
Sustained occupancy reduces receptor numbers, so the pituitary stops responding.
- 3
Testosterone or oestradiol falls to castrate or menopausal levels.
- 4
In children, the pubertal hormone signal is removed, halting progression.
- 5
Depot microspheres release the peptide steadily over one, three or six months.
What it's studied for
Reported and studied effects
- Castrate testosterone levels within about a month
- Pain and lesion reduction in endometriosis
- Stabilisation or regression of pubertal signs in children
- Reversible bone density loss during treatment
- Initial hormone flare in the first week
Research protocol notes
Research context onlyResearch context only - prescription medicine. Typical licensed dosing is 3.75 mg intramuscularly every 28 days or 11.25 mg every three months, with paediatric dosing weight-based and adjusted as the child grows; trials track testosterone, pubertal staging or pain scores over 6 to 12 months.
These figures are described so you can understand what researchers did. They are not a dose, a schedule, or a suggestion — and they are not a substitute for a doctor.
Possible side effects and contraindications
Safety profile
Possible side effects
- Hot flushes
- Loss of libido and erectile dysfunction
- Bone density loss
- Headache and mood change
- Vaginal dryness and bleeding irregularities
- Injection-site reactions
- Tumour flare at the start of treatment
Contraindications and cautions
- Pregnancy and breastfeeding
- Prior hypersensitivity
- Spinal metastases need antiandrogen cover during the flare
- Undiagnosed vaginal bleeding
A side-effect list is never complete, and these are not the only situations that warrant caution. Anything unexpected, or anything you are unsure about, should be discussed with a doctor before use.
Evidence assessment
Randomised trials across prostate cancer, endometriosis and central precocious puberty with objective endocrine endpoints, plus widespread regulatory approval.
References
- 01European Medicines Agency - Decapeptyl product information
- 02Carel et al., Long-term mortality after gonadotropin-releasing hormone analogue treatment for central precocious puberty, JCEM 2015
References link to published literature, regulator pages or literature indexes. Where a link points to a search, it collects the peer-reviewed work on that molecule rather than a single study.
Related
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Degarelix
A GnRH antagonist that suppresses testosterone immediately, without the initial hormone flare of agonists.