Legalize recreational use of marijuana Threw out the U.S

Marijuana is not harmful i have heard it can help kill cancer cells it helps with epilepsy it helps with autisim and many more medical problems. Marijuana is also safer then beer and many legal drugs. But there should be a limit on it like you must be 21 and you must sign some kind of contract promising not to sell it to minors or so you cant sell it at all. I myself have never done drugs but i know people in states were medical or recreational use is legal and they have said it has made them feel better and they have not been violent in any way like beer makes you.