30+ days for marijuana and 1-2 days for cocaine

if i were you i would probably go into a doctor to see if he tests positive for drugs. Because if you do it at home you might not be as consistent as the doctor.

It depends on how much was consumed, but typically:

Marijuana is an all-time drug.
It never really leaves.

Though the symptoms last only so long.
The effects, as in his body himself,
is about a good month or two.

For cocaine, not too long.
It can range from 3-4 to 6-9 days.

Though to be honest with you,
I couldn’t give you a definite answer for sure.
It varies.
This is from my knowledge and understanding.

You can home test him,
but most kids do this-
If you tell him you’re home testing him,
he can easily just drink a lot of water.

A lot of water clears the system of the drug if a lot is consumed. The second he takes that test and it says he’s fine; than it is in fact not lieing.
This is if your son knows to drink water to clear his system of this.

Otherwise, if you’re doing this at random and with no warning, you will get better results. Just watch him if he drinks too much of water and such.

I would go to your or his doctor about this and speak with them if this becomes a problem of testing him or any other matter.

Let’s just hope he’s drug free.
We need our kids to learn that they don’t have to use them, and that there are other ways to make them feel better.
Our kids need to hear that there’s other ways to handle things.

God Bless and Good Luck.