Heroin is extremely addictive as opiates. However, no one is ever too far gone. There is always the chance for someone to get clean and sober, IF they want to be clean and sober. Does your son want to get clean, the drug at his point is irrelevant.

Can't ~ "one time use & being addicted" is different for each person.. Heroin is, as Dee said< extremely addictive. If he was taking oxycodone, hydromophone, vicodin, etc, he was already using Opiates.. this is how so so many of our kids begin their "Heroin careers". I also want to say, that no one is too far gone.. If he is breathing, there is always hope..
Never give up mama, just don't enable him to use.
Blessings

I was happy when my son gave up drugs (he did everything BUT heroin) and ONLY drank. Boy, was I wrong.
It doesn't matter what they are addicted to...it matters that they have the addiction.
It is so common for all the folks who use pills to not be able to get them, or they get too expensive, and they switch over...to an even more unsafe drug.
I agree with my wonderful friends, no one is ever too far gone, and don't enable.
I will add that if they want to use, and not quit, you have to set your boundaries in stone. don't let them use you too.
The sooner he quits, the better, obviously.
I am very sorry you are experiencing this.