Lol...that was my favourite!
I think you have done the right thing. As Dr. Throwl pointed out, creatine is a dangerous steroid which mimics the natural estrogen sources in the body. This causes vast fluctuations in the osmolarity of the body's cells and may damage them or lead your son to a life of addiction.
Many weight-lifters have chose to use this drug because (as we all know) estrogen allows the body to push out that ONE extra rep of exercise which is crucial to muscle building and weight gain.
The problem is that people are unaware of how to cycle common steroids such as this. (safe use and cycling of creatine provides low risk of damage or addiction). This common for of addiction is actually called "The Dark-Side" as it allows you to gain massive amounts of weight (legally) and your skin becomes darker.
He should probably stay away from it altogether, but if he is going to use it, make him use 0.025g pre-work-out and then drink 4+ grams of protein powder after for maximum muscle gain.
Yours in friendship,
Trolololal1234, Co-Leader of PuffedMuscleCentre"
The Dark Side....HAHHAHAHAHAHAHA
fucking gold ^^