Overdose Smoking Heroin?
I go to some length in my book Heroin User's Handbook to show that the casual user is best to ingest heroin by smoking. One of the main reasons that I believe this is that it is very hard to overdose by smoking heroin. But it can be done. I knew a man who died as a result of smoking heroin. His death was due in large part to the fact that he was drunk when he smoked the heroin. Had he not been drunk, he probably would not have died. Just the same, had he not smoked the heroin, he probably would not have died.
Don't Mix Heroin and Alcohol
Before I go on, remember the number one rule of heroin use: Never, never, never, never, never use heroin with alcohol. That means, don't drink and then use heroin. Don't use heroin and then drink. Don't drink and use heroin at the same time. If you die, you can't read Heroin Helper, and that just isn't acceptable. (You might be able to come up with some other reasons not to die; so don't mix heroin and alcohol.)
"Snorting" Isn't As Safe As You Think
People think snorting is safe, but it isn't. The problem is that it takes a long time to feel what you have snorted. So you can snort way too much before you even begin to feel the effects. The same goes for IM and SC injection. It's like setting a time bomb.
IV Injection Has Different Problems
IV injection is dangerous for another reason: you feel what you are doing quickly, but you can do an enormous amount all at once. I suppose this wouldn't be a problem if you felt it right as you did it. But there is a 15 - 60 second delay - more than enough time to ingest enough to die.
Why Smoking Is Safe...
Smoking is the safest way to ingest heroin because you are always "up to date" with the effect of the drug. By smoking, you ingest a small amount of heroin. You feel the effect within 10 - 20 seconds (yes, faster than an IV injection). So under most circumstances, you will pass out before you can smoke enough to overdose.
...But Not Completely Safe
There are other ways to die from using heroin, however. You could smoke a lot, pass out, vomit, and suffocate. Or you could pass out in the wrong place and be murdered. Or you could pass out, knock over the candle you were using, start a fire, and burn up.
There are no guarantees. Heroin is not a particularly dangerous drug. It isn't Rice Krispies®, and even Rice Krispies® can kill you. By using smoking as an ingestion method and always using with someone else, you greatly reduce your risks.