I take 20mg of simvastatin at night,heard it affects your muscles,when i first lay down my muscles will crack,it dont do it as much during the day or later at night,is it the simvastatin doing it?how can i stop it,i take collagen and vit d every day?

I don't think simvastatin is a cause of cracking of.muscles,tendons,joints or ligaments & it's telling that you don't mention muscular soreness during daytime activities, but muscle soreness & achiness are possible side effects of simvastatin even in small doses. Pravastatin & rosuvastatin, being hydrophilic, are much less likely to cause muscular discomfort.