You'll be the shortest 1% on the planet due to non-natural factors.

Chriky is confused because "percentile" has a specific meaning, and "below the 99th percentile" means everyone except the top 1%. The GP meant to say "lower than 99%", which is the 1st percentile.

An assertion that ADHD medication causes first percentile height/weight is also terribly absurd.

Yeah... especially as it's apparently given to significantly more than 1% of children!