What is the difference between deep hyaluronic acid filler and surface one?

There are many different types of hyaluronic acid fillers on the market. Each is typically designed for different applications (like lips, cheeks, smile lines, etc). Deep fillers are usually products like Voluma which are often placed for volume improvement rather than to fill in specific lines. Surface (or superficial) lines respond better to different fillers, and something like Vollure or Volbella can usually be placed closer to the surface of the skin.Be sure to see an expert physician injector to review your concerns and all of the options in detail.

Deep fillers are good for providing volume, while surface fillers are good for wrinkles, like lip lines. It takes 1-2 weeks for final results with HA fillers. Best, Dr. Emer

Thank you for your question.  It really all depends on what areas you want to address.  If you are addressing loss of volume, then a thicker filler is often preferred to inject more deeply.  If you want to address fine lines, then a thinner filler is often injected more superficially.  I recommend a consultation with a facial plastic surgeon to discuss your specific goals.  

The answer depends on what you are having treated. Certain fillers are placed deep to add structural support to the soft tissues such as when Sculptra Aesthetic or Restylane Lyft are injected into the midface/cheeks while other fillers are placed more superficially such as Restylane Defyne when treating laugh lines or Restylane Silk when treating lip lines. 

Years ago when fillers first hit the market, they were more commonly called dermal fillers, as the treatment goal was to typically address more superficial lines (wrinkles), with varying success. As the understanding of how the face ages and development of better fillers and injection techniques, the concept of injecting deep, to replace bone and refill the deep fat pockets of the face evolved. 
Without a consultation, it’s difficult to say which treatment is best for you. But typically, the idea of “restoring the foundation”, is preferable to than just “fixing the siding”. 
Whatever path you choose, make sure you have an doctor who understand these differences and does not try to overfill, but takes a gradual approach to facial contouring, allowing the tissues to adequately accommodate each treatment, before adding more.