There is no definite time frame for tenofovir to be effective when taken. In the treatment of hepatitis B, HBV-DNA usually decreases when it is reviewed after one month of taking it. Tenofovir is an antiviral drug that is more commonly used to treat HIV infection and chronic HBV infection. The combination of the drug and other reverse transcriptase inhibitors can also be used in the treatment of HIV-1 infection, chronic hepatitis B. However, due to the physical condition of each patient, the severity of the disease and the adopted treatment program and other aspects of different, take the drug to see the effect of time will also have some differences. Patients must strictly follow the doctor’s instructions when using the drug treatment, in the use of drugs may appear general weakness, diarrhea, abdominal pain, dizziness, dyspnea and other adverse reactions. It is contraindicated in patients who are allergic to tenofovir, tenofovir disoproxil or any of the excipients in tenofovir tablets. Patients with risk factors for severe renal insufficiency, or underlying renal insufficiency, should monitor their renal function under the supervision of a doctor when using the drug therapy, and need to adjust the drug dose in combination with creatinine clearance.