I used to tell people in your situation that they had to wait until age 22....and then I changed my mind. As long as the product is FDA-approved, any other use of it is considered off-label. Off-label is not necesarily wrong, it's just not on the approved indication list. For example, Botox was approved for use between the eyebrows, but we commonly used it on the crow's feet. Fast-forward and now there an "on-label" indication for crow's feet. but for years that area was an off-label use. We also commonly treat infections with antibiotics that were approved for one use but are commonly used for another.Does anything change physiologically from when you are 20 until you are 22? Not much. Are you a legal adult? Yes. So I have an informed consent document that states very clearly that saline is available to you, that silicone is off-label, etc. And if a 20-year old want to do silicone, I am OK with that. As long as you are aware of the off-label situation.i understand that not everyone does it that way, but it makes sense to me.