The combination antiretroviral therapy (cART) inhibit HIV replication effectively. However, synergy among these drugs has not been well considered. The dose of drugs used as monotherapy is the same as that used in combination therapy. Tenofovir+lamivudine+efavirenz is still the first line regimen of cART in developing countries. The side effects of these drugs are related to the concentration of drugs. Based on our previous data, we aim to evaluate whether reduce the dose of tenofovir and efavirenz could decreasing the incidence of the side effects while not scarifying their virological efficacy.