If they're used responsibly. I was a heroin user (everyday) for the past three months. I came home from school this summer to the realization that most of my best friends were all getting into "hardcore" drugs. One snorting oxycontin and xanax everyday; a few others getting into heroin. After a few weeks of being home, in which I used xanax from time to time , I decided to try a bump of heroin with my buddies (snorting). And let me tell YOU punk, the first time I got high from heroin was great, it was amazing! A few days after that , I was using it everyday (snorting). I was able to use everyday because where I live can get hookups really easy, and the stuff we got was white and pure (very good). Anyways after using over a few weeks. my high progressively diminished over time. And by this time, a few of my friends were starting to inject. However, I continued to snort it (I would NEVER inject myself with anything), but I knew that I had to quit before school started back up. So, eventually I quit - cold turkey and about two weeks ago. For me, detox was hard (hot flashes, sleep difficulty, leg aches) and lasted for about 4 days; this is because i never developed a high enough tolerance (made a bag/pack of the stuff last about 2-3 days).. but I can't imagine what I would have gone through if I had developed a more serious addiction, or if I started using higher dosages, or if I started using a needle. I don't think heroin is a horrible or evil drug. In fact, I may decide to use it again, but I'm going to wait at least a few months before deciding anything. If I'll do it again, it will be in small amounts and NEVER MORE than two days in a row.