It is made of Hyaluronic Acid (HA), which is a substance that naturally occurs in the dermis of the skin. It can be found in many beauty products, as it is a hydrophilic molecule, meaning that it attracts water. It can hold up to 1000 x its own weight in water making it an excellent hydrator. Some common brands of lip injections are Restylane, Juvederm, Beloterol, Teosayal, Emervel now rebranded with Restylane, Perfectha etc.