Perlane Vs. Restylane, What's the Difference?

Restylane and Perlane are both hyaluronic acid filler products made by Medicis, Inc of Scottsdale, Arizona. They are similar products with important differences. Perlane is a more highly crosslinked product than Restylane. Crosslinking is the process that allows these products the ability to persist in the tissue and provide long term benefits. In the case of Restylane, this product seems to last for about a year or more. Perlane persists a bit longer and that time frame seems to be 4 to 6 months longer than the Restylane.
The products look similar however, when injecting the two products, it is immediately obvious the difference between the products. Restylane flows more readily than Perlane. However, Restylane is not as "smooth" (or runny) Juvederm a competing product made by Allergan, Inc. This ability to flow is helpful in the lower eyelid and lip edge where too much fullness is very easy to see after a service. As a result it is important that for treatmented in this area, to use a product like Restylane that holds in the tissue and is not too runny but at the same time can be manipulated and sculpted.
Restylane is perfect for the sensitive lower eyelid area and lip edge. For other areas of the face, there is abundant fat to help hide filler. In areas like the cheek, chin, nasolabial fold firmness of the material to resist dissipation is important for volumizing. Perlane is perfect for this role. Should there be an overfill issue after a treatment, both products can be adjusted with an enzyme called hyaluronidase that can be injected and softens the unwanted fullness.

"Perlane" is not a product that is being used any longer and has been re-branded as Restylane Lyft. As others have stated, Restylane Lyft (formerly known as Perlane) has more cross-linking in order to allow the product to last longer than regular Restylane. Both of these products are hyaluronic acid fillers.
This property also makes Lyft a "stiffer" or "thicker" product than regular Restylane, which means Restylane is a more appropriate product for lip augmentation, superificial wrinkles, and tear troughs. Lyft can be used in other areas where it can be injected more deeply such as the cheeks or nasolabial folds. 
All the best,

Restylane and restylane lyft are both hyaluronic acid, but restylane has smaller particles than restylane lyft.  Restylane is better for more superficial concerns or to buttress thin skin (eg tear-trough).   Restylane lyft is better for lifting the cheeks and softening nasolabial folds and marionette lines.  There is also a third restylane product called restylane silk.  This product has very fine particles and is my favorite for very superficial textural concerns, including the lines of the lip area.