Study aim: Study the effect of Favipiravir on the outpatient treatment Covid-19 patients Design: 70 outpatient patients with covid-19 will be randomly assigned to intervention and control (placebo) groups. randomization will be done by simple randomization via www.randomization.com. This is a phase 3 trial with parallel groups and triple blinded. Settings and conduct: This study will be held in 3 outpatient center. Blinding will be triple blind, so that neither patient, physician, the outcome assessor and data analyzer are not aware of the groups. patients in intervention and placebo groups will be treated for 5 days and followed for 1 month. Participants/Inclusion and exclusion criteria: Inclusion criteria: definite case of Covid-19, age over 18, presented within 5 days from the start of sign and symptoms; Exclusion criteria: severe cases with SpO2 under 90, using an antiviral in previous two weeks, previous infection with covid-19, using an steroid in previous two weeks, being under treatment with steroid, previous allergic to Favipiravir, renal failure, hepatic failure, pregnancy, lactating. Intervention groups: Intervention: Favipiravir 200 miligram, 8 pills daily for 5 days; Control: Placebo, 8 pills daily for 5 days Main outcome variables: Treatment failure, Side effects