Hormonal Regulation FDA Approved

Triptorelin

Also known as: Triptorrelina

Molecular Identifiers

Molecular Formula

C64H82N18O13

CAS Number

57773-63-4

PubChem CID

25074470

UNII

9081Y84BKD

Molecular Weight

1311.45 Da

Overview

Long-acting GnRH agonist. Used in specific hormonal protocols. A single dose can have a prolonged effect lasting weeks.

Approved by the FDA as Trelstar for the treatment of advanced prostate cancer and as Decapeptyl for central precocious puberty. GnRH agonist with extended- release formulations of 1, 3, and 6 months.

Triptorelin is a potent GnRH receptor agonist with a clinically important biphasic effect: initial stimulation causes a transient LH/FSH surge (flare), followed by receptor desensitization and sustained suppression of sex steroid production. This profile supports its use in advanced prostate cancer, endometriosis, uterine fibroids, and central precocious puberty. In off-label sports protocols, it is discussed as a tool to restore the HPG axis after anabolic steroid cycles.

It is a peptide with solid regulatory approval: it has been cleared by the FDA as Trelstar (advanced prostate cancer) and as Decapeptyl (central precocious puberty), with extended-release formulations of 1, 3, and 6 months. Outside these indications, low single doses (about 100 mcg) are prescribed subcutaneously or intramuscularly in post-cycle protocols, under medical supervision, usually through compounding pharmacies.

Within the HPG axis, triptorelin is the long-acting GnRH agonist: it stimulates first and then desensitizes to suppress. It shares the receptor with gonadorelin (endogenous GnRH, short/pulsatile without clinically meaningful desensitization) and with cetrorelix (antagonist, immediate suppression without a flare); triptorelin is also useful as a single low dose to restart the axis. Compared with kisspeptin-10 (upstream) and hCG (which acts on the gonad), it works at the pituitary level.

Sequence (1 letter): QHWSYWLRPG
Extended notation: pGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH₂

Contains D-tryptophan at position 6

Half-life

~6-8 hours

Administration Route

Intramuscular or subcutaneous

Category

Hormonal Regulation

Mechanism of Action

  • Potent GnRH receptor agonist
  • Initial stimulation followed by receptor desensitization
  • Long-lasting effect (3-4 weeks)

Dosage Protocol

Data compiled from the literature. This does not constitute medical advice.

Parameter Value
Dose 100 mcg per injection
Frequency Once every 3-4 weeks
Timing Any time of day
Duration According to protocol

Reported Side Effects

Adverse effects described in the literature. Severity and frequency vary between individuals.

  • Hot flashes
  • Decreased libido
  • Bone pain (initial flare)
  • Injection site reactions
  • Fatigue

Product Properties

Purity >99%
Appearance White lyophilized powder
Solubility Soluble in water and bacteriostatic water
Source Solid-phase peptide synthesis (SPPS)
Storage Lyophilized: -20°C for up to 2 years, 2-8°C for up to 6 months. Reconstituted: 2-8°C for up to 4 weeks. Protect from light and moisture. Avoid repeated freeze-thaw cycles.

Presentations & Preparation

Vials of Triptorelin found in the research market:

100 mcg2 mg

Reconstitution

  • Diluent: Bacteriostatic water
  • Volume: 1 ml per vial
  • Inject the diluent slowly against the vial wall
  • Gently swirl until completely dissolved
  • Never shake

Storage

  • Lyophilized: Refrigerated 2-8°C
  • Reconstituted: Refrigerated 2-8°C (use immediately)
  • Protect from direct light
  • Use promptly after reconstitution
Reconstitution Calculator

Scientific Studies

Published studies on Triptorelin.

2017 · Adv Ther

Efficacy of testosterone suppression with sustained-release triptorelin in advanced prostate cancer

Breul J, Lundstrom E, Purcea D, Venetz WP, Cabri P, Dutailly P, Goldfischer E
2010 · Fertil Steril

Anabolic steroids purchased on the Internet as a cause of prolonged hypogonadotropic hypogonadism

Pirola I, Cappelli C, Delbarba A, Scalvini T, Agosti B, Assanelli D, Bonetti A, Castellano M

Related Peptides

Argipressin

5-20 IU or 1-4 mcg/kg · As clinically needed

Cetrorelix

0.25-3 mg per injection · Once daily (0.25 mg) or single dose (3 mg)

Gonadorelin

100-200 mcg per injection · 2-3 times per week

HCG

250-500 IU per injection · 2-3 times per week

Kisspeptin-10

1-10 mcg per injection · Per research protocol

α-MSH

0.5-2 mg per injection · Once daily or every other day