MSFinals-1859

A 35-year-old woman comes to the clinic asking for the progesterone-only injectable contraceptive. She reports that she has used it before and it has been effective for her. However, she has a medical history of migraines with aura and irritable bowel syndrome. She is currently undergoing treatment for breast cancer and is awaiting further tests for unexplained vaginal bleeding. Additionally, she is a heavy smoker, consuming around 20 cigarettes per day. What makes this contraceptive method unsuitable for her?