Hi, ! pretty much covered everything I would have written. I found some studies that were supposedly done on this supplement, but I haven't had the time to make sure they were reputable studies done by reputable research facilities.
That said, I know that wasn't what you were asking about. I think Lee had some good suggestions and the only thing I would add would be to please check with your doctor before trying any new treatment. Specifically, St. John's Wort can interact with medications, so you will want to run any supplements you want to try by your doctor or pharmacist. Please do your research and only purchase supplements from safe, reputable sources.
Apologies that I can't offer any guidance beyond that and please do let us know how it goes if you can find and try this supplement.
Best, Erin, MultipleSclerosis.net Team Member.