I'm so sorry to hear you are going through this. May I ask how he gets hold of these cannisters. At 12 years old I wouldn't think anyone would sell them to him.

Is he being given help by professionals?

I am sorry to hear this, and your hands are tied to a point as you cant be with them everywhere. Is it peer presure from other kids? Is there a drug helpline you can contact, or pop into your local doctors surgery they may have leaflets of somewhere you can talk too.
I remember being at work one day and a friend told me she had seen my daughter doing this in the town with some lads, she drove me to where they were but they had gone, luckily her daughter knew where one of the lads lived, when i went around she was there (thank goodness) the lads mother more or less told me to get lost when i told her what they had been doing, she dismissed it, i took my daughter home and told the lad never to contact her again. They had both denied it of course. I told my daughter how wrong it was and the affects it would have on her, scabs around the mouth etc, luckily from that day (as far as i know) she never did it again. I never saw signs from it, but i was paranoid about any sort of canisters being in the house. She's a lot older now and lived to tell the tale. But i know it can be serious. They think its a bit of fun.
Maybe your son is just experimenting, but it does need to be stopped before it causes too much damage.
I do hope you can get help soon.
Good luck.

I have witnessed young friends dying from this type of abuse.....not a pretty sight.......the damage that is caused to the body is dreadful!!.......and some people even experience psychotic behavior....before their death!

No simple answers.....like any addiction, I'm affraid.

I know exactly how you feeling.
My son did the exact same to me at 13yrs of age.
Later he turned to harder and more dangerous drugs.
Have had him in so many rehabs, only to find out later in life.
My son has bipolar disorder.
Best wishes for you.

An elixir of Amethyst may help to lessen the addiction. Amethyst is known to help stop addictions, to remove the 'urge' to take the addictive substance. I myself have used it to stop an addiction.

Your son wouldn't even need to know you were putting some drops in his water, or food etc