I don't think so. The first time I took it it was at night and 5-10mins later I became really sleepy. Then I got into the habbit of taking it everyday for 1-2 weeks or so and I didn't have any problem sleeping, but maybe it varies from person to person, I don't know. The only problematic part is that St. John's Wort may cause photosensitivity in your skin, and eyes (not sure about the eye part), so you gotta be careful when you go outside and use sunscreen. Oh and Saint John's Wort also causes conflict with lots of medications so that's also problematic aswell. Just to be sure, don't take it if you're taking any sort of medication (or talk to your doctor about it if you can), and don't take SJW in combination with any other antidepressants.

I was taking SJW for like 2 weeks in tea form and I noticed an improvement in my mood, but it may have been a placebo, so I don'know, but soon after I stopped taking it I started to become depressed again so I think it works.

Usually the normal dosage is 900mg throughout the day (3 pills), but you can start at the minimum dose (300mg) and see if it works for you.

In terms of the actual ingredients, I heard certain brands of Saint John's Wort (Hypericum Perforatum) are better than others but I'm not sure which ones are the best. I think the ingredients should be accurate though. Sorry it's all I know.