While many people can benefit from HRT, some groups shouldn't undergo the therapy. It's important to talk to your doctor about any conditions that could prevent you from HRT treatments. For example, those with a history of reproductive cancer — including breast, uterine, and ovarian cancers — are not good candidates for HRT. The same goes for smokers, those with a family history of blood clots, or those with a family history of high cholesterol and liver disease.