Longevity of hyaluronic acid dermal fillers – current state of knowledge

Introduction:
Hyaluronic acid, is the most abundant glycosaminoglycan in the human body that is highly hydrophilic, with 50% amount located in the dermis. Skin aging is naturally accompanied by hyaluronic acid reduction, which could accelerate the dehydration, loss of elasticity, and wrinkling of the skin. The injection of dermal fillers gives desirable cosmetic outcomes by erasing skin rhytides or restoring facial volume loss, or both. Hyaluronic acid-based filler was launched because of its characteristics. The aim of the study was to find available data regarding longevity and changes over time of hyaluronic acid deposits in skin of patients that underwent hyaluronic acid injection.

Methods:
A systematic review of the published literature was conducted in accordance with the PRISMA guidelines. The literature search was performed in June 2023 and included PubMed and Google Scholar databases.

Results:
Our analysis included 8 studies involving different hyaluronic acid formulations and different assessment methods of longevity and diffusion patterns of hyaluronic acid. Hyaluronic acid fillers turned out to be longer lasting than 12 months with cases exceeding more than 2 years lifespan. Different methods of evaluation can be used to assess post- injection results. These include MRI, high- frequency ultrasound, 3D imaging as well as Wrinkle Severity Rating Scale changes and subject- reported satisfaction. Delayed complications of hyaluronic acid, injections are rare. It is important for practitioners to note the possibility of them occurring even after more than 2 years post-injection.

Conclusions:
There is indication that hyaluronic acid fillers may be longer lasting than previously thought and this should be considered when preparing treatment plans for patients and diagnosing potential long-term adverse effects.