Everyone potentially at risk of acquiring HIV should consider taking PrEP. You must have a prescription for PrEP. You can get one from your family doctor or an HIV care provider. Your doctor will confirm that you meet the requirements for taking PrEP and don’t have medical reasons not to take it. The most important thing to do before starting PrEP is to get tested for HIV. If your HIV test returns positive, then PrEP will not treat it adequately. If you start taking Truvada or Descovy when HIV positive, the virus can become resistant to it.