Other forms of thiamine do not work for me. Allithiamine has transformed my life. I was suffering from burning neuralgia in my lower legs that made my life a misery. I have an underlying sulfite sensitivity that impacts on thiamine levels so I've added this to my regime of other bioactive vitamins and minerals. You can absorb more ordinary thiamine by consuming fresh, raw garlic, but this is definitely much more sociable way of doing it. A little pricey compared to the USA, but with restrictions in place it's nice to know I can actually get it in the UK.
A friend sent me a link to a video she thought would be of interest to me (Dr. Chandler Marrs on Vitamin B1 (Thiamine) - Mitochondria's Gateway to Energy) I watched. I bought the tablets and my symptoms of ME/CFS significantly improved :)