How old do you have to be to smoke weed?!

No age requirements to smokeweed amd no age requirement to be arrested for it.

Law Enforcment Officer, Narcotics Division

Stupidly enough, it's illegal in the US no matter how old you are, or how many doctors tell you it'll be the best medicine for your condition
P.S. merlineaton: That's why most people ate it before it was illegal. Once it was illegal, they realized that smoking it is the most efficient and cost effective way, even if it's the least healthy way.

i think it's 155, you should not smoke weed, or anything else for that matter. been there done that, when i think back, i can't remember what ever was good about it, there are many things that can make you much happier, like helping others can give you a really good high.