evidence: Dietary or herbal supplements are not recommended to prevent or treat COVID-19. Colloidal silver supplements aren't safe or effective for treating any disease. Oleandrin, an extract from the toxic oleander plant, is poisonous and shouldn't be taken as a supplement or home remedy. [...] COVID-19 medicine helps people who are at risk, diagnosed or who have symptoms of the disease. You can get medicine to manage symptoms. Some medicines stop the virus that causes COVID-19 from spreading in the body. And some COVID-19 medicines help manage the body's immune system response.