Both types of filler have been demonstrated in clinical trials to last much longer than the standard collagen injection. The occurrence of an allergic reaction is extremely rare, as the solution does not include ingredients derived from animals. Restylane and Restylane Lyft are made from hyaluronic acid, which is a sugar molecule already present in the human body. A natural substance, Hylauronic Acid naturally adds volume and fullness to the skin and is both biodegradable and compatible with human hyaluronic acid. Because of this compatibility, it is not necessary to be tested for skin sensitivity.