Study aim: The determination of the effect of methylene blue along with complementary materials in decreasing the symptoms of disease, hospitalization and mortality in COVID-19 outpatients who referred to pulmonary clinic Design: A randomized, controlled trial, based on outpatients with Covid-19, which has two parallel groups. Settings and conduct: Covid-19 patients with positive PCR or HRCT who refer to the lung clinic and treatment with methylene blue (1 mg/kg/day) along with complementary materials Participants/Inclusion and exclusion criteria: Inclusion Criteria: Outpatients with COVID-19 referred to a lung clinic confirmed by HRCT or PCR. SPO2 is between 70-96 after taking off the mask. Age over 18 years old. Exclusion Criteria: Pregnancy Severe impairment of liver and heart Renal insufficiency including severe renal impairment G6PD enzyme deficiency Intervention groups: Covid-19 outpatients treated with standard medical therapy (supportive therapy) and methylene blue along with complementary materials Main outcome variables: Oxygen pressure saturation - Respiratory rate-Headache- Cough- Fever- Shivery- Respiratory distress- Chest pain wall- Vomiting- Diarrhea- Hospital stay- Mortality rate after one month.