My niece is going to be 16 in march and for her birthday she want colligen injections.I thought you had to be 18 to get this done but my sister is letting her get it done if it is legal.Could you tell me what age must you be in the u.k ,ireland and the u.s.a to get this done.Can you get it at 16 with parent concent?btw I do not agree with this.