Hi Lindy,
i think there might be something in the idea. I have been slim from childhood. I have been the same weight since 21. I am 5 feet 10", and 9 stone in weight (56 Kg).
I have developed such a sensitivity to levodopa, that I am now on an average of 125 to 150 mg after over 19 years since diagnosis. Not only that, but I get raging dyskinesia from this microscopic amount, indicating that I have had too much levodopa. The levodopa is taken as Stavelo.
I take 50 mg at 8-00am, together with Mirapexin, an anti cholinergic and Azilect I am on until 11-00am, and take 25mg.This lasts until 1-30pm when I take another 25 mg. This lasts me to 4-00pmpm when I take another 25mg plus Mirapexin etc. I am then on until around 7 to 8 pm. If I am going out, [I] take another 25mg.
How do others do? Has anyone else with a low body weight developed a sensitivity to levodopa? Or a heavy person not sensitive. It may need advanced pwp's who slowly develop a sensitivity (slim build) or lack of it (when heavy build) over many years of consuming sinemet.Previously, about 10 years ago, even 50 mg levodopa would not switch me on, let alone 25mg. I get the 25mg by breaking a 50mg Stavelo in half.

Ron