so it tends to induce vomiting, and a lot of dysphoria and distress. dr. bigelow: the main subjective effect of heroin when it's used is to produce a subjective, dreamy euphoria in individuals. they tend to be sedatedat . the effects ll last perhaps an hour or so. with chronic use, the nature of the cycle becomes not just being high and then back to normal, but being high and then experiencing withdrawal sickness and then using the drug and getting back to normal. once i got addicted to heroin, my life-- i can explain it real simple, i was either in jail, or out on the street using heroin. narrator: there are also health risks associated with using heroin. if it's injected, there's a risk of hepatitis, of aids, of hiv, of many infectious diseases that are transmitted by the needle. for both heroin and cocaine, many of the public health problems one sees are related to the illegality of the drugs, and the difficulty individuals have in getting it, and in self-administering it in sterile ways. so they're very high-risk of infection. narrator: people who are