Anastrozole’s side effects include hot flashes (bouts of fever) and malaise, while exemestane’s side effects include anorexia and depression. It is not possible to compare the two in terms of which one has fewer side effects. 1. Anastrozole side effects: common side effects include hot flashes (a bout of fever), malaise, arthralgia, nausea, headache, thinning hair, diarrhea, drowsiness, vaginal bleeding, hives, trigger finger, skin vasculitis, and so on. It is used for the treatment of breast cancer in postmenopausal women and is contraindicated in pregnant women. 2. Exemestane side effects: common side effects include anorexia, insomnia, depression, drowsiness, carpal tunnel syndrome, hot flashes (a bout of fever), abdominal pain, alopecia, rash, osteoporosis and so on. It is used for the treatment of early invasive breast cancer and is contraindicated in pregnant and lactating women. If you need to take the above medication, it is recommended to consult a doctor and use the medication under his/her supervision.