Can St Johns Wort make you sleepy/more tired than usual?

[cocolepew]

I've been on it for a couple of weeks and now I am incredibly tired. Reading another thread in Mental Health someone took it at night (in conjunction with something else) and said it helped her sleep. I'm very tired during the day, 'heavy' limbs, falling asleep on the sofa, but I find it hard to sleep at night (sleeping on the sofa doesn't help!).

Oh just Googled it, fatigue is a common side effect, might start taking it at night instead.