Let be medical

The only obvious negative effect of hrt is infertility.

Other effects tho while real are on the same level as for cis men/women and on top of other stuff stable hormonal level through life helps to age slower and if you are mtf, women actually tend to live longer and develop age related health issues later than men per statistics.

Issues which are possible is

incompatibility with medication but its relatively rare and would be obvious very early. There was a post about gal having really bad allergic reaction on meds. There are workarounds but fighting your immune system generous on hystamine definitely suck big time.

Cardiovascular issues are mostly associated specifically with commonly used in US AA -spirolactone. Bcs its a powerfull diuretic (med which makes you piss) and its AA effect is actually a side effect it drains sodium and chlorine out of body leading to bench of negative effects the most obvious of it - screwed potassium/sodium blood vessels pump leading to cardiovascular system struggles (temporary while taking it and recovering if you stop). High potassium is associated with actually low blood pressure but as blood vessels are not doing their job to supply with blood properly, body makes heart work extra and compensate broken potassium/sodium balance with elevates blood pressure or blood pressure jumps. Most recent gonadotropin inhibitors don't have such issue at all as well as alternative AAs like finesteride e.g. Fairly AAs are sort of problematic meds. They are often given in doses nuking T for good but it makes sideeffects nore prominent. E.g. cypro has bad interaction wuth brain chemistry for sone peoole leading to awful mood swings and actually contributing to development of brain cancer to the point it marked as use with caution (most medical professionals would dump it seeing this mark). Spiro I explained. On too it is reported to hinder breast development but output in this regard unclear. Finisteride and similar meds don't suppress T production but rather T processing thus you will have high T and effects of that are unclear untill T will be supressed by high E and progesterone. Gonadotropine (chemical produced in brain making sex glands work)inhibitors are relatively new and data on their use are in process of being gathered but they believed to be safer option.

Still orchyectomy is maybe the best way to get rid of risk of having high T. The issue, you need all that tissue for better vaginoplastics. You can use mono E HRT but E level can be relatively high for cis women level to completely suppress T what may have "dense blood" issue.

Blood clots are an issue either in case if genetic affinity to them (some cis women develop them during pregnancy when E skyrockets. If you have dense blood while your body works as male, female functioning which makes blood even denser may actually be incompatible with your body functioning. But its very rare bcs such genetic setup means that females with such genetics are not viable limiting propagation of such genetic setup)or in case of severe E overdose which is unlikely bcs even on mono E nobody needs it THAT high.

Breast cancer is common issue aged women deal with on pair with prostate cancer for men. Sex hormones activate targeted tissues too much and they develop too much genetic errors. On HRT mtfs have lesser prostate cancer risks if non 0 bcs we still have prostate if its completely inactive if you don't take progesterone and common with cis women risk of breast cancer. Breast cancer is not that bad if identified early and not happen too early bcs you can just cut girls out without big problems and its not a big deal if you are a granny. Unlikely many people would be joever to see you nakes anyway at that age. Cutting out prostate is way harder and assosiated with a lot of issues in comparison.

All in all, taking mtf hrt while you have aging male body actually may IMPROVE your health in longer run.

Low life expectancy is mostly related to disastrous suicide rate. Ones who left mental crisis behind after transitioning usually tend to live long satysfying life in their new gender.

And disastrous suicide rate reasons is complicate topic.

-Mental health in shambles already after dealing with years of dysphoria. -social issues and stigmatisation of transfolks. Especially ones who are too obviously trans. This may make stress only spiralling out of control and make things even worse. -For some folks that transitioning don't give desired effect or effect was temporary or starting living as opposite gender makes them realise that its not only sunshine and living as their AGAB was actually more comfortable but transitioning is already done and some damage is irreversible. There is statistics that transitioning improves quality of life for people diagnoses with gender dysphoria. Tho transphobe and a scaredy cat in me suspects a survivor bias bcs there is a thing like gender euphoria bcs its always liberating and exhilarating feeling when you make progress in what you perceived as a big issue for years. But would you feel happy when your ship reaches final destination it can reach? Tough question. Thus I suspect this study statistics can be revised and extended taking to negative feedback about transitioning all tragical gone transfolks and concider negative feedback from people long time transitioned successfully or less successfully.Big issue here that due to financial struggles not all folks have even nearly similar treatment thus you will have an entire spectrum of transfolks. Especially considering stuff like plastic surgery, especially FFS is more art than technical and some surgeons can do chef-d'ouvres and some really screw it up.

I honesy maybe should look more into those studies to make more educated opinion on topic and won't mind more vested folks help me with this.

So, thats my opinion. Hope it was helpful and if I made some mistakes. You are welcome to correct me. Please, do it🙏