Actually, I don't know that it supresses the immune system at all.
Q
Estrogen has been studied in suppressing MS with some success but, I don't know about the doses with respect to HRT. From what I know I would not hesitate to go back onto HRT. My hysterectomy was in 1993 and I only went off the estrogen in 2004 to help lose weight . (It worked)
Estrogen is not an immune suppressant per se.
Quix
You might want to message Quix about your post to be sure you get a response from her as she hasn't been able to spend a lot of time with us lately.
It makes sense that estrogen suppressess the immune system to some extent as estrogen levels remain high during pregnancy when a woman's immune system needs to be suppressed so her own system doesn't attack the 'intruder' fetus.
I'm not sure exactly what your concern is with patch use if you have MS. The DMDs are actually immune system modulators themselves, meaning they tamp down the tendency of the MSers immune system to over-react.
I haven't heard that HRT use is incompatible with MS but I don't pay much attention to that type of medical info these days.
Mary