Patients should inform their doctor if they do not feel well while taking Zocor. Like other medications, Zocor can have side effects, although they do not affect every patient. Notify your doctor if you experience: Hair loss, Muscle cramps, Insomnia, Poor memory, Feelings of depression, Erectile dysfunction, Breathing problems including persistent cough and/or shortness of breath or fever Some side effects that may occur while taking this medication include: Gas, Stomach pain or cramps, Diarrhea, Constipation, Heartburn, Headache, Blurred vision, Dizziness, Rash or itching, Upset stomach or nausea Contact your doctor immediately if you experience: Unexplained muscle pain, tenderness, or weakness, Brown/black urine, Tingling in hands or feet, Jaundice, Jives, Painful swollen joints, Bruising more easily than usual, Swelling of the tongue or face, Pregnancy Other side effects not listed above may also occur in some patients. Consult your doctor if you notice any additional effects.