I had been involved in a research study about Zocor. I had previously been on 20 mg without any seemingly side effects. Had a brief 'wash out' period and was rx'd 40 mg. On 40 mg I have had the eye twitching, face numbness, weakness, especially in my hands and fingers, fingers became sore, and general muscle stiffness. However, the most troublesome side effect was depression to the point of teariness. I have been off the 40 mg of Zocor for a week and a half and the depression seems to be lifting and I am sleeping much better. Hope these comments help others.