How old to get a lip piercing in Norman, Oklahoma?

well, i got my labret at 14 with parental signature in NC, and i had to take it just last year (at 20 yrs old) because it was growing into my lip OMG, and i was wearing the oversized ring they put in for piercing so it definitely wasn't too tight, also it eroded my gums away from my front two bottom teeth, i have to say a ****** up place to pierce for real... but yea, prolly 18 w/o consent