Many factors come into play.
As a cosmetic physician with over a decade of experience using various dermal fillers in Phoenix, I get this question all the time! The answer is...it varies.
While most of the currently available, FDA approved, dermal agents have a 12-month duration of action, depending upon where the product is placed in the face and the total amount of the product injected, the duration can vary from 6 months to 18 months. Other factors that affect the duration of these agents come from the characteristics of the products, themselves. The most common dermal filler agents, such as Restylane® and Juvederm® are comprised of hyaluronic acid (HA). The hyaluronic acid molecules are cross-linked to form an injectable gel. Newer HA fillers such as Juvederm Voluma®, for example, have different cross-linking processes that prevent them from being broken down as easily, leading to a longer duration of effect. Voluma® has been approved by the FDA for up to 2 years however, in their clinical study, they used large amounts of product to attain this degree of longevity, more than the average patient requires.
Non-HA fillers, such as Radiesse® and Bellafill®, for example, are made of either water-based or bovine-collagen gel matrix with microspheres that stimulate the patient’s natural production of collagen. Since these result in new collagen formation around the product itself, the duration of action depends largely upon how quickly the body is able to break-down the microspheres. Bellafill® currently holds a 5-year indication for duration from the FDA, however those of us who are familiar with this product know that the actual duration is much longer, and may even result in permanent change, since the body is unable to break down the microspheres made of PMMA (poly-methyl methacralate). Radiesse® is made up of calcium hydroxylapatite microspheres that the body breaks down more easily with results lasting approximately 12-18 months.
Autologous fat can be used in lieu of traditional dermal fillers for those looking for a potentially permanent effect. That said, like fat in other parts of our bodies, as we gain or lose weight, the fat that has been injected into the face for contouring, can also vary depending upon the patient’s weight. I find fat to be somewhat unpredictable and use it more for its skin rejuvenation benefits, due in large part to the high concentration of stem cells found in fatty tissue - as opposed to using it solely for volume replacement.
Other, patient-related, factors can influence the duration of dermal filler effect; fitness buffs, for example, seem to “burn through” their filler faster than more sedentary patients. Finally, one of the largest influencers when it comes to duration of dermal fillers is the amount of the product injected. Often times, we tend to underdose patients with fillers due to the associated costs of these products as well as fear of looking overdone. However, when a patient is under-treated, we find that their filler may look great initially only to wear off quickly once the initial swelling has subsided. So, it is important to fully correct areas with enough filler product to ensure desirable and lasting results.
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