EPO stimulates bone marrow to produce RBC and only RBC. So your blood becomes saturated with RBC, these are fresh RBC as epo acts rather quickly. While on TRT your RBC count will go up a bit slower, meaning as it goes up you get old and new cells all mixed in your blood. With epo everything is fresh and readily binds to oxygen in the air. With old red blood cells sometimes they don’t always pick up all 4 oxygens or sometimes they won’t let go of one of them when they get to your capillary bed. This means you get less O2 delivered and a hell of a lot thicker blood. Those guys also have different adaptations on a cellular level, they have more cellular mitochondria to use the extra O2 that’s delivered to the cells where as someone like you or me may not be able to use all of it. We just get stuck with all the sides. Their heart is also much better than ours so they can handle the thicker blood with relative ease as there heart has much more room to pump and is stronger. Ours will have a harder time doing so as it’s not nearly as strong.
There’s also training state. EPO was famously used by Tour de France guys because of its RBC generating capacity. Your RBCs can only bind to oxygen so many times before they have problems delivering and picking oxygen up. This can lead to stuff like above where you end up having RBC with bound oxygen going back to the lungs which isn’t efficient at all. While you’re doing the Tour de France you’re taxing your RBC like crazy and they begin to degenerate. Yes tour guys start off with more RBC than they finish with. This is where EPO comes in or blood doping via EPO weeks before. New fresh RBC in the blood means more oxygen delivered which means they can perform better.
In short, if you want to use EPO you need to be pretty well trained. It’s not something your average joe could take and fee instantly better on. It’s used to give them an edge, maybe 5% but that makes all the difference. You still have to be able to use the oxygen delivered effectively and you still have to know what you’re doing because EPO will kill you, and it’ll kill you very very very fast. Any number of things can happen such as DVT, ruptured arteries and veins, aneurysms, strokes, heart attacks (most common), pulmonary embolisms etc. Pretty much anything that can happen to your circulatory system can happen when you use EPO, just imagine taking it 2 steps further than what you think is possible. Cyclists drop dead because of the stuff.
I’m not one for heavily regulating drugs but this is some nasty sh*t to mess with.
