The liver issues are with oral tablets that dissolve in the gut. They are processed by the liver before entering the bloodstream. This is known as "First Pass". The liver metabolizes the hormone, reducing its effectiveness. This process also affects coagulation factors, which underlie issues with blood clots and stroke.
This does not apply to sublingual, transdermal patches or gels, or injectables because they are absorbed into the bloodstream first, do their work, and then are cleared by the liver. High estradiol levels in the blood can still pose a risk, as everything in the bloodstream eventually gets cleared by the liver.
My doctors still monitor my liver enzymes in my lab tests. I haven't taken any oral estradiol tablets since 2021. I was on patches for several years, then switched to injectables. However, the VA likes to test everything.
Your doctor is correct:
Routine monitoring of liver function tests (LFTs) has been removed from both transmasculine and transfeminine Endocrine Society recommendations due to a lack of evidence that hormone therapy causes adverse liver outcomes.
