Sorry Kellye...I just now seen this.
I don't know very much about the herbal med's which St. John's Wort is one of those. Be careful when you start taking herbal's because they are not tested like other drugs on the market. Most of them are not FDA approved, but yet somehow they still sell them (that's something that I don't understand...since you might be taking something harmful).
I've never heard of St. John's helpping night tremors. It's usually used for mood inhancement or mild depression. I did find a website that has a discussion forum, so maybe you'll find the info that you're looking for on there. That site is: http://www.sjwinfo.org/
I'm sorry I couldn't help you more. I just don't know much about herbals at all...I do know that at our Pharmacy, we sell a lot of it.
Hope the site that I gave you helps you find what you are looking for! Good luck!