As with any medication, taking estrogen comes with it's own set of risks and possible side effects. In my main post on hormone therapy I allude to the fact that HRT is very dangerous so I have compiled a list below of the risks associated with taking estrogen.
The goal of HRT in regards to trans women is to lower a person's testosterone levels to normal female levels while increasing their estrogen to normal female levels. This is accomplished with a number of medications and requires routine blood testing to insure these levels stay correct.
In addition to hormone levels there are a number of other things that need to be monitored such as blood lipids, prolactin levels and liver health. There may be other risk so please talk to your doctor about specifics. Your current health condition may play into this a great deal.
Blood ClotsThis is one of the biggest risks for male to female transsexuals. As many cissexual women know taking estrogen increases your risk of developing blood clots. This risk is greatly amplified if you smoke!!! If a clot does develop they can lead to all sorts of problems including heart attack, stroke and pulmonary embolisms (all of which can cause death). Also, because of the clotting risks you will be required to stop taking estrogen for a period of time before any surgery so make sure you disclose that you take it regardless of the reason for surgery. For example, I just had gallbladder surgery and had to hold off a week because they surgeon wanted me off my estrogen just in case. Better to err on the side of cation then end up dead!
ProlactinomaA Prolactinoma is a type of pituitary gland tumor. They can develop as a result of estrogen therapy. While they are usually benign they can be dangerous leading to headaches, vision problems and even permanent blindness. If you take estrogen your doctor will monitor a particular hormone called prolactin. This will help them determine if something is wrong in your pituitary gland. Again, there is a low risk but certainly not a 0% risk. I know of at least one trans woman who has required surgery because she developed a Prolactinoma so it does happen.
GallstonesEvidence shows that HRT can increase your risk of gallbladder disease and I can attest to it. I can't say with 100% certainty that my stone was caused by my taking estrogen but it sure grew fast once I started taking it. I also have a trans friend who has had her gallbladder out as well. Be very aware of this if you have a family history of gallstones.
Possible Risk of CancerThis is a controversial topic so I will not go to much into it here. Some evidence says that HRT increases your risk of breast cancer while others say it doesn't. I will just say ask the doctor (like with all of these points) and know your family history!
See my main Breast Cancer, Self Breast Exams and General Breast Health page.
Heart DiseaseAnother controversial topic but again, ask you doctor and know your family history.
InfertilitySome people see this as a side effect, some see it as a benefit; either way HRT will make you infertile. If you want to have children in the future make sure you plan accordingly by banking your sperm.
RegretI know that the risk of regretting transition is very low but it can and does happen. This is the ultimate decision really in the steps leading up yo your transition... Do the risks of what you will need to do out way the benefits of doing them? Are you really comfortable with the permanent effects of estrogen therapy (i.e. breast development and infertility)? Are you ready to come out (after all breasts are hard to hide)?
While it is easy to make a snap decision on these questions, they really are not things you should rush to find an answers to! Take your time, talk to your doctor and your therapist, and enter into this process with both eyes wide open!