from what I have read this hyaluronidase is used so that your skin will absorb better. I read the article too and it appears that they injected the lips and then used the hydrocortisone. i assume that they did this so that the skin would better absorb the hydrocortisone. they did not say that the hydrocortisone was just applied to the injection sites like you stated. they also said that the hydrocortisone did not work alone without the injections. so i think it safe to assume they did the injections so the skin would absorb the hydrocortisone better.