Trelstar (generic: triptorelin) is a prescription medication used to treat prostate cancer in men.  Trelstar belongs to a group of drugs called gonadotropin releasing hormone (GnRH) agonists, which help slow the growth of prostate cancer cells by affecting testosterone production in the testes.

This medication comes in an injectable form to be given into the buttock by a healthcare provider, once every 4, 12, or 24 weeks.

Some of the common side effects of Trelstar include hot flashes, headache, and bone pain.