The recent introduction of injectable products in the market, hyaluronic acid based, indicated to counteract the signs and symptoms of tissue atrophy in vulvar area, inevitably generates the need to deepen the subject. The focus will be placed on the biochemical peculiarities and the ractional use of these products, to clarify how they are “processed” before being put on the market and therefore of what is infiltrated into the tissues at the end of the production process; what is the precise anatomical site in which they can be used, for what indications, with what techniques, contraindications and side effects. Among the products based on hyaluronic acid, first it is important to dwell on the big difference between non- cross-linked and cross-linked gels hyaluronic acid based, having themselves two different indications. The firsts are indicated for cutaneous and mucosal atrophy with eutrophication and biostimolating purposes, the seconds are used for iatrogenic scarring results, for example post-episioraffia or for reconstructive purposes in hypo / dystrophies of the fatty body of the Labia Majore and in macroscopic iatrogenic scarring with tissue loss. Also the technique by which they are injected is different (with needle or blunt tip cannula), with different contraindications and side effects. With a practical slant, the author intends to develop the topic with the aim of providing valid help to the doctor in his practical clinic.