Taking entecavir alone generally does not result in the conversion of surface antigen. Entecavir is a first-line antiviral drug and a nucleotide analog, which is used to inhibit the replication of the hepatitis B virus. However, entecavir alone is unable to remove the hepatitis B virus from the body, so it is generally difficult to induce the hepatitis B virus to turn the surface antigen negative. Currently, the purpose of treating hepatitis B is not to cure the disease, but to inhibit viral replication. Entecavir can reduce or even stop the inhibitory activity of hepatitis B virus, which can help to control liver inflammation, slow down the progression of liver fibrosis and cirrhosis, and avoid the induction of hepatocellular carcinoma. Common adverse reactions to entecavir include nausea, dizziness, headache, and fatigue, etc. Entecavir is contraindicated for those who are allergic to entecavir, and discontinuation of the drug will cause exacerbation of liver disease, so patients should not stop taking the drug without authorization. In addition, entecavir has certain risks, patients need to use under the guidance of a specialist, not unauthorized use.