Soma (Carisoprodol) usefulness as PED

I have read through some others sucessful use of Tram as a pre-race/ hard effort PED, and this got me wondering about Carisoprodol. I know it is a muscle relaxer so that doesn't sound like the ticket for pre work -- perhaps for post work recovery ..? I question its pre work benifit because it seems to act as a buffer between the brain and muscle pain. I have access to a bit to experiment with and was wondering if it was worth it or better just left for post-crash muscle spasms.