Also available in 1 mg 10 mg 25 mg 50 mg 100 mg 500 mg and bulk. Please contact Fisher for quotes. Giredestrant tartrate (Estrogen receptor antagonist 1) is a novel orally active selective and effective non-steroidal estrogen receptor antagonist. Giredestrant tartrate strongly binds to ER resulting in the failure of ER to activate the transcription of targeted genes and promoting the degradation of ER protein. Giredestrant tartrate can be used to treat tumor diseases. purity: 98%