Tertomotide (also known as GV1001) is a synthetic telomerase-specific peptide vaccine patented by Norsk Hydro Asa for the cancer treatment. The agent was initially developed as a cancer vaccine, for example, against pancreatic and prostate cancer. Telomerase, a reverse transcriptase normally repressed in healthy cells, is overexpressed in most cancer cells and plays a key role in cellular proliferation. Vaccination with Tertomotide may activate the immune system to mount a cytotoxic T-lymphocyte response against telomerase-expressing cells. Subsequently, in vivo studies have demonstrated the efficacy of Tertomotide in alleviating benign prostatic hyperplasia (BPH) symptoms by reducing the size of the prostate gland. The mechanism of action of Tertomotide has been proposed to be through its dual activity as a GnRH inhibitor and 5a-reductase inhibitor. The GnRH antagonist activity has been established by co-immunoprecipitation assay, demonstrating an interaction between Tertomotide and the GnRH receptor, which was abolished by pre-treatment with anti-GnRH receptor antibody.