Most modern dermal fillers use hyaluronic acid as their base material. Different formulations vary in their cross linking density, particle size and rheological properties, which affect their firmness, integration with surrounding tissue and suitability for different treatment areas. Product selection for any individual treatment is a clinical decision made by the practitioner based on the area being treated and the client’s individual anatomy.
Clients increasingly research cosmetic injectable products before their consultation, and while informed clients tend to have better consultations, product choice is ultimately a clinical decision that depends on the area being treated, the individual anatomy being worked with and the specific goals of the treatment. This article provides a plain English overview of what dermal filler products are and why the distinctions matter.
This overview is written from the clinical perspective of Corey Anderson, AHPRA registered nurse (NMW0001047575, registered since January 1996), at Core Aesthetics in Oakleigh.
“Good information changes the quality of the decision.”
What Hyaluronic Acid Filler Is
Hyaluronic acid is a naturally occurring polysaccharide found throughout the human body, with particularly high concentrations in skin, connective tissue and joint fluid. It has a remarkable capacity to bind water, with a single molecule capable of holding up to 1000 times its own weight in water. In its natural state, hyaluronic acid in the skin is continuously broken down and synthesised by the body, with a turnover of days to weeks.
Dermal filler products use a stabilised, chemically cross linked form of hyaluronic acid that resists the enzymatic breakdown that would rapidly degrade naturally occurring hyaluronic acid. The cross linking process creates a gel with physical properties very different from the natural form. It is this cross linked gel that is injected into or beneath the skin to restore volume, improve structure or address hollows and lines.
Why Different Products Have Different Properties
The physical properties of a hyaluronic acid filler product are determined by several manufacturing variables. The degree of cross linking affects the gel’s firmness and resistance to breakdown. The particle size of the cross linked hyaluronic acid influences how the product flows and integrates with surrounding tissue. The overall concentration of hyaluronic acid affects its volumising capacity. These variables combine to produce products with significantly different clinical handling properties, suited to different treatment applications.
Products with higher firmness and larger particle size are better suited to providing structural support and volume in deeper tissue planes, such as the mid face, jawline and chin. Products with lower firmness and smaller particle size integrate more superficially and are better suited to refinement applications such as lip definition, fine line softening or the delicate tear trough area. A single filler product used across all areas of the face would not produce optimal results in any of them. This is one of the reasons product selection is a clinical skill and not simply a matter of brand preference.
Product Selection Is a Clinical Decision
Clients sometimes ask about specific brand names in advance of their consultation, having researched them online or heard about them from friends. While it is worthwhile understanding what product categories exist, the specific product selected for your treatment is a clinical decision that belongs to the consultation. Your practitioner selects the product based on the area being treated, the depth of placement appropriate for your anatomy, the specific clinical goals of the treatment and their experience with how different products perform in different tissue environments.
What you can and should ask about is what general category of product is being used and why it is appropriate for your specific treatment area. A practitioner who can explain the rationale for their product choice in clear clinical terms is demonstrating the kind of specific knowledge that relevant treatment experience produces.
Reversibility
One of the most clinically important properties of hyaluronic acid based filler is that it can be dissolved using hyaluronidase, an enzyme that breaks down hyaluronic acid. This reversibility means that incorrectly placed filler, filler that does not produce the intended result, or filler in the context of a rare complication can be addressed. It is one of the primary reasons hyaluronic acid filler has become the standard of care in cosmetic aesthetic medicine.
Read more about how dermal filler treatment is approached at Core Aesthetics on our dermal filler hub page and our article on dermal filler safety.
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General Information Only. This article is general in nature and does not replace a consultation with a qualified health practitioner. Treatment outcomes, suitability and risks vary by individual. Any medical or prescription treatment options can only be discussed and provided where clinically appropriate following an individual assessment.
AHPRA Registration: NMW0001047575 (Nurse, registered since January 1996) | Core Aesthetics, Oakleigh VIC 3166
All prescription treatments are assessed and administered by an AHPRA registered health practitioner. Suitability is determined individually at consultation.
Clinical References
General Information Only. This article is general in nature and does not replace a consultation with a qualified health practitioner. Treatment outcomes, suitability and risks vary by individual. Any medical or prescription treatment options can only be discussed and provided where clinically appropriate following an individual assessment. Last reviewed April 2026 by Corey Anderson, Core Aesthetics.