There certainly is something to high-dose B1 therapy that is helpful in relation to PD motor symptoms. But does not help with the non-motor symptoms. The best dose seems to be between 1gm to 4gm per day, but very much depends on your body's ability to accept such a high dosage. I started at 1grm (500mg at breakfast and 500mg at 2-3pm. No later than 3pm as can affect your sleep. If you have no bad reaction after 7 days, increase the amount by 500mg per day. If you start noticing any bad reaction, stop taking for a week and then restart at a lower dose until you find the right amount your body will accept. It is not a cure so treat it as an adjunct medication along with your normal [[treatment:Levodopa/Carbidopa:55d534f51fcaa397470006dd]] med. It is important to also take a multivitamin capsule daily so that you are balancing the other B vitamins so that your system does not get out of kilter. For more detailed info, Google, Dr. Constanini B1 therapy protocol for PD.

Recent blood tests showed I was deficient in B12, so the doctor has me taking a daily supplement of this (over-the-counter dose). I also take magnesium to help control leg cramps

B1 x 2 daily (adding 3 one soon)
B12
St. John’s wart
Multi vitamin
Nuralli for gut connection

My husband is taking 300mg/day for about a month now. We're upping by 100mg shortly. He has some small relief - his voice is normal again. Whatever else is too minor to detect. We started with the mononitrate form (wrong kind of B1) until we figured out that was the wrong form of B1 -- it needs to be just HCL alone. We are supplementing with additional B vitamins and will eventually go to magnesium when we figure out what works. There is a book called Parkinson's and the B1 Therapy which reports on Dr. Constantini's efforts for those interested in trying out this option. I am, myself, taking B1 for more energy and I can say I do truly feel more energetic and upbeat. Could be my imagination, but I think not. I will shortly add magnesium, in liquid form, to my own regimen.
My husband is, of course, still taking carb/levadopa.

If anyone experiences any relief whatsoever, with B1, please, please share.

My dr has me taking b12 1000 mcg