a provocative question. should the country be helping to make illegal drug use safer? dr. sanjay gupta takes a closer look at users who are starting to test their drugs to try and avoid deadly overdoses. >> kenya has been using heroin off and on for more than 20 years. lately she says each time feels like a real gamble. >> put it in the cup, yes. and you just pour it onto that. i use the end to stir it. >> what you're watching is tanya testing for the presence of the deadliest drug in america. >> and it just takes a small amount, and just dip it in. >> between may of 2020 and april of 2021, more than 100,000