When I was an active heroin addict, I would do a small test shot of new product before doing a normal dose. If it was too strong, then the match-head sized sho

When I was an active heroin addict, I would do a small test shot of new product before doing a normal dose. If it was too strong, then the match-head sized shot would get me off, and I would know to go easy on it. If nothing happened, I would wait 5 minutes and then raise the dose, until I was where I wanted to be. I somehow managed to avoid overdosing in the 8 or so years I was using. I don't know what part of that can be attributed to caution or luck, but there was probably a lot of luck involved. Either way, that chapter of my life is over, and I am grateful to have come out alive.