Dont know what should be so disgusting about "St. Johns herb". Its regularly used in my country, so we have during winter about 7 hours of daylight, and additional 80% of the time its anyway foggy or you are in a mountains shadow or whatever. St. Johns simply makes you more sensible to light, so your skin and eyes get sooner infomations about it being sunny, even if its still dim and foggy. This causes your body to produce more "Wake up and be active, its broad day!" hormones, so you are less tired and have a better mood. You simply have to care for, where you use it. If you have sunny winters, then using Johns Wort is not so good, because your skin might react badly to sunlight, due to oversensitivity. As well that its in bigger amount lightely poisonous, so you should not use it, around pregnancy. Because of Johns Wort being broadly used here, people normally know of the dangers of it, and care as example to use sunoil when skiing on sunny day on mountains. (Because of the higher locations, there is less UV-rays filtering, additional the snow will reflect the sun again, so you easily get triple amounts of sunrays in your skin. If its then extra sensitive to sunlight, due to Johns herb... it can cause problems. ^^)
Simply care for having good informations on certain herbs you want to use. They are nothing else then medications, and every good effect can as well have negative side effect, as well that certain persons simply might react badly towards a certain herb.