I tried a bottle of it several years ago. I didn't notice any effect, but then I didn't use it long enough to really give it a serious trial. The dose probably should also have been higher to increase the chance of seeing some results.
I tend not to have much faith in herbal remedies in general. The stuff I've read on St. Johns Wort has been conflicting -- some studies say it helps a little and others say it's just plain useless.
I didn't use it for my SA ...per se... I used it for my depression about 2-3 years ago when I was totally and completely depressed. It actually helped me out a lot but it caused serious tightness in my chest. Because it worked I used it until I couldn't stand the tightness of my chest. Then a few months later I used it again until I couldn't bear the chest pain. I haven't really been depressed since! One day here and there, that's it.
A couple years before that I had been on zoloft which sent me from manic-depressive to depressed all the time. I think the St. John's Wort helped to get system going in the right direction because I haven't taken anything since I took the St. John's Wort and I'm fine as far as the depression goes!
I tried it several years ago but it seemed to make my SA worse. I stopped taking it after suffering a panic attack. I had dropped by to visit a neighbor who invited me into her house. When her daughter joined us in conversation in their living room, I noticed myself beginning to sweat and I panicked. I quickly walked to their front door and waited to be let out (like some pet). How embarrassing was that!