Estrogen being super low might be seen in dry joints, and like you said dry lips, etc.
Personally, super low estrogen is BAD. You want to minimize it, but not totally get rid of it. In fact, I think some of these anti-e's available may even be overkill. Let's not forget the days of 6-OXO. I mean granted 6-OXO might not be the strongest anti-e ever created, BUT it boosts test safely. RXT causing severe knee dryness and soreness is kinda weird, wouldnt you think? Just an idea...
I think illness can even be attributed to this sometimes. People have dubbed the term M1T-flu, but I forget if this is estrogen related or not, so don't quote me on it. Do a search on side effects of the new anti-e's coming out.