Tweeti have under the supervision of a pro. i have to say that it works very well but i wouldnt make the suggestion to take the plunge unless you are serious about stepping on stage and have been hammering away for years. it is a great tool for the tool box for competitors but not a quick fix. i used 3ml in each tri and 3ml in each delt and 3mls in each inner calf every wk for 5wks on and 5wks off for about a year. it will help stretch the fascia out in areas that you are trying to bring up but it isnt anything that is superior or dramatic but more of a icing on the cake kind of deal