Common side effects of hormone therapy include hot flashes, fatigue, joint pain, mood swings, and vaginal dryness. SERMs like tamoxifen can also increase the risk of blood clots and endometrial cancer. AIs may lead to joint pain, bone thinning, and an increased risk of fractures. GnRH agonists can cause menopausal symptoms, such as hot flashes and decreased bone density. It is important to discuss potential side effects with a healthcare provider to manage and mitigate these effects.