Dermal Filler Pharmacology

Hyaluronic Acid Based Fillers

As the name implies, the main ingredient of these fillers is Hyaluronic Acid (HA), a substance naturally occurring in our bodies and more abundant in our skin and joints when we are young. The hyaluronic acid in the upper layers of the skin gives it plumpness and glow.

Hyaluronic acid fillers are sometimes referred to as dermal fillers. That is not a correct description because specially formulated thicker HA fillers are also used for injections below the skin (below dermis) into lower facial layers, to restore volume and contour.

Different manufacturers of HA fillers use slightly different manufacturing process and technology, and their fillers differ by the particle size of HA molecules, concentration of the HA in the carrier filler gel, the type of cross-linking between HA molecules, HA gel hardness/thickness (aka G prime), and cohesivity of the HA gels.

Those differences are responsible for the variance in duration and lifting properties of different fillers. Cross-linking of the hyaluronic acid molecules is necessary to make HA fillers last.

All HA based fillers share the following properties:

  • the procedure is fast and non-invasive with immediate results
  • the results are temporary
  • the filler can be dissolved.

All in all, from all the facial volume restoration options, HA based fillers are the easiest, most conservative, minimal risk, minimal side effects, and short term – least expensive procedure, leading to its great and continuously rising popularity.

Pros of HA fillers:
  • Hyaluronic Acid is a substance naturally occurring in our bodies. It is not perceived by our bodies as a foreign material so there is no risk of rejecting it or developing an inflammation or nodule/granuloma around the injected substance.
  • Immediate results.
  • Because the results are immediately visible during the treatment procedure, it is very

    difficult to unintentionally overdo the HA fillers.

  • Even if a patient does not like the result, HA based fillers can be dissolved by an

    injection of a Hyaluronidase enzyme.

  • Very low risk of developing adverse reactions.
  • Little to no downtime.
  • Very non-invasive.
  • The duration of the results gets longer with repeat treatments
  • Lower price per syringe compared to other more permanent options.
Cons of HA fillers:
  • The results are not permanent as over time the body absorbs the injected HA. To maintain the result, repeat procedures are required every 4 to 36 months.
  • Long term, due to the repeat expense, this may be a more expensive option than a more permanent solution, especially if a lot of volume needs to be restored.

Hyaluronic acid (also known as hyaluronan or hyaluronate) is naturally found in many tissues and fluids, but more abundantly in articular cartilage and synovial fluid (SF). Hyaluronic acid (HA) content varies widely in different joints and species. HA is a non-sulphated, naturally occurring non-protein glycosaminoglycan (GAG), with distinct physico-chemical properties, produced by synoviocytes, fibroblasts, and chondrocytes.

Example of HA Filler

BELOTERO BALANCE (+) click here

Information on adverse events from post-market surveillance of BELOTORO BALANCE are included in the Package Insert (PI) and Patient Information Guide (PIG) based on an assessment of seriousness and potential causal relationship to BELOTERO BALANCE. Please see the PI and PIG available on for a complete list of these events.