Biotin is water soluble - so does not stay in the body for long. lt is excreted in urine and faeces. With tablets containing fillers - it is these that you can overdose on. Too much magnesium/calcium. The body does make its own biotin - but for some reason people with MS and Diabetes do not absorb enough. Which is similar to VitD3 and B12. lt is not toxic.
After 4 weeks of taking it l can see some benefits - and yesterday a friend mentioned how good my skin and hair looked. l have kept quiet about taking the Biotin for this reason. l wanted to see if anyone noticed. lts like doing my own trial. My tummy problems have improved and l find l can get a bit of a wriggle of my toes - and also lift my knee up. All things l could not do for years. l get about with my rollator and find l am leaving it behind in the kitchen. Also, l am not dragging my left leg all the time. Early days - but l shall stick to it for now.