Before taking sofosbuvir, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, other liver problems (such as hepatitis B), diabetes.

If you have diabetes, your blood sugar may be lower with hepatitis C treatment. This can increase your risk of low blood sugar, so your doctor may adjust your diabetes treatment plan. Tell your doctor right away if you have symptoms of low blood sugar such as sudden sweating, shaking, fast heartbeat, hunger, blurred vision, dizziness, or tingling hands/feet.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, sofosbuvir should be used only when clearly needed. Sofosbuvir, in combination with ribavirin or peginterferon, must not be used during pregnancy by either the pregnant woman or her male partner. The combination may harm an unborn baby. Reliable forms of birth control must be used whenever at least one sexual partner is using these medicines together. Female patients should keep using birth control for 9 months after stopping treatment. Male patients should keep using birth control for 6 months after stopping treatment. If you or your partner becomes pregnant, or if you think you or your partner may be pregnant, tell your doctor right away.

It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.