Hyaluronic acid is a preferred ingredient for dermal fillers because it is naturally occurring in the body and, therefore poses fewer risks of negative reactions. However, the half-life of hyaluronic acid is notoriously short, with a hyaluronic acid filler able to degrade by half in just 48 hours. To create longer-lasting HA fillers, pharmaceutical companies created more durable formulations by chemically cross-linking the HA filler strands. These new formulations of hyaluronic acid filler can last from six months to two years based on the formula, the amount injected, and the treatment area.

There are two kinds of possible breakdown of HA filler that affect its durability: metabolic and mechanical. Metabolic breakdown refers to how quickly a patient’s body metabolizes or “breaks down” the hyaluronic acid filler. Mechanical breakdown of HA fillers is related to the movement of the area and will differ depending on the individual’s unique movements (such as facial expressions) and habits (for example, massaging the skin too vigorously will break down injectable hyaluronic acid more quickly). Some areas of the face, such as the smile lines and around the mouth, break down hyaluronic acid filler faster due to repetitive movement, which is why hyaluronic acid lip filler may need to be touched up every four to six months. Other areas, such as the under eye where there is little mechanical pressure due to the soft and thin nature of the skin, injectable hyaluronic acid may last up to several years.

Injectable hyaluronic acid has been in use in Europe since 1996, and hyaluronic acid filler procedures have grown rapidly in popularity since the first FDA-approved HA filler, Restylane®, came on the US market in 2003. Improvements in hyaluronic acid filler formulations have steadily decreased the occurrence of negative reactions and increased the possible applications for injectable hyaluronic acid.

Lowered taboos around procedures, such as hyaluronic acid filler, increased exposure on social media of hyaluronic acid lip injections and other HA fillers, contribute partly to a more casual approach to injectable hyaluronic acid. Unfortunately, a black market of bootlegged hyaluronic acid fillers on the internet and non-credentialed injectors are ready to take advantage of these consumers. The results have not been positive and often dangerous. Any substance injected into the body represents a medical procedure and should be treated with that level of caution and due diligence. When considering an injectable hyaluronic acid procedure, consult only with a board-certified dermatologist or plastic surgeon using reputable and tested hyaluronic acid filler.

The correct age to start hyaluronic acid filler, if at all, is a personal choice. While all skin will begin to lose bone mass and collagen around age 26, the speed and expression of visible aging of the skin is determined by personal genetics and lifestyle and will be different for everyone. In general, most patients interested in HA fillers begin hyaluronic acid filler injections between the ages of 40 and 54. However, with newer applications for injectable hyaluronic acid, such as reshaping a nose or jawline, HA fillers are becoming popular with younger patients as well. Some medical professionals even recommend the use of hyaluronic acid fillers as a preventative, anti-aging procedure, while others prefer to begin after the first signs of aging. Consulting with an experienced clinician with thorough knowledge of facial anatomy will help determine if hyaluronic acid filler is the appropriate choice.

One of the significant advantages of hyaluronic acid filler over other dermal fillers is the non-permanent nature of HA fillers. Permanent and semi-permanent fillers potentially have more long-term side effects, such as stretching out the skin causing pockets of sagging. But, a judicious amount of hyaluronic acid filler that is properly placed does not pose a risk of creating areas of sagging or stretched skin. A more common outcome is for injectable hyaluronic acid to correct sagging skin due to aging by replacing lost volume. As the body metabolizes the hyaluronic acid filler, the skin will simply return to its previous state. This may appear more loose to the patient who has become accustomed to fuller, plumper skin from the HA fillers.

Although rare, it is possible for hyaluronic acid filler to migrate or move. This generally happens within the first few days after receiving the injectable hyaluronic acid when, for whatever reason, the HA filler moves before it has bonded with the tissue at the site of injection. To prevent HA filler migration, avoid any firm manipulation of an area treated with hyaluronic acid filler for three days after placement of the HA filler. Many practitioners offering services such as microcurrent or massage-based facial treatments will recommend waiting two weeks after a hyaluronic acid filler to avoid any possible adverse effects on injectable hyaluronic acid.

In other cases, a provider may massage the HA filler or instruct the patient to do so for distribution of the material, a common occurrence with hyaluronic acid lip injections. Lumps that appear after receiving injectable hyaluronic acid may be due to swelling or a small hematoma at the inection site, which will resolve within a few weeks. It’s best to alert your provider to any changes or uneven textures in the treated area. Should an issue arise with the hyaluronic acid filler, it can usually be corrected easily with the use of an enzyme, hyaluronidase, which can dissolve the hyaluronic acid filler completely in 48 hours.

It is a good idea to sleep on the back and with the head slightly elevated for 48 hours after a hyaluronic acid filler. After this initial 48-hour period, there is little risk of HA filler migration, although some practitioners may recommend back-sleeping for a few weeks after hyaluronic fillers, depending upon the location, the amount of HA filler used, and the health of the skin.

Properly placed hyaluronic acid filler poses a small risk for negative side effects. But even in the best conditions, some patients may have an allergic response to injectable hyaluronic acid. In these cases, the HA filler is simply dissolved with an enzyme.

Although rare, possible side effects include:

• red, swollen, bruised skin
• itchy skin
• lumpy skin
• infection at the site of injection
• pain
• bleeding
• prolonged firmness
• an abscess or nodule
• localized tissue death (necrosis)
• haemorrhage of the eyes
• double vision or loss of vision

Hyaluronic acid filler consists of a sugar molecule produced naturally in the body. Hyaluronic acid (HA) is hydrophilic, meaning it attracts water and expands. This is how it fills a deep space or fill a line. It is a clear, gel-like substance, and depending on how the hyaluronic acid filler is engineered, it can be firm or elastic, depending on the desired application. The first patented HA product, Healon®, was obtained from rooster combs and was approved for use in eye surgeries in 1979.

Animal-derived hyaluronic acid filler was the standard for some time, but it is expensive to process and presents risks of an immune response to accessory proteins bound to the HA filler. Innovations in production led to the manufacture of hyaluronic acid filler via large-scale bacterial fermentation with genetically modified strains. Most injectable hyaluronic acids in use today are from similar non-animal sources. The costs associated with producing bacteria-derived hyaluronic acid fillers are lower than animal-derived, and the process presents greater flexibility for creating products with higher molecular weight and complex cross-linking. These properties allow for hyaluronic acid fillers to provide more structural support and slower degradation. This variance is responsible for the diverse hyaluronic acid fillers on the market today, thus expanding the possibilities of injectable hyaluronic fillers for cosmetic purposes.

Hyaluronic acid filler procedures are not available for a patient with active acne lesions or any infection (including herpes) of the treatment area. Patients with autoimmune disorders (or undergoing immunosuppressive therapy), blood clotting problems, uncontrolled/untreated diabetes, or an allergy to any components of injectable hyaluronic acid are not candidates for HA fillers.

Pregnancy and breastfeeding patients should consult with their clinician when deciding whether or not to proceed with hyaluronic acid filler. Although there are no studies on the effects of injectable hyaluronic acid whilst pregnant or breastfeeding, many professionals advise against it out of an abundance of caution. However, some patients may choose to pursue treatment with injectable hyaluronic acid while pregnant and/or breastfeeding.

Hyaluronic acid filler is administered by injection with a needle, so it isn’t a completely pain-free procedure. However, most HA fillers are formulated with a lidocaine numbing agent that is activated immediately to reduce any patient discomfort. Some practitioners also administer an anesthetic gel before administering the injectable hyaluronic acid to maximize patient comfort.

One of the benefits of injectable hyaluronic acid is an immediate result, with improvements seen over the next few days as the hyaluronic acid filler settles in the tissues and begins being absorbed by the body. The final results of HA fillers is achieved after about one week and should last from 6 months to a year or more, depending on the formulation and placement of the hyaluronic acid filler. In general, a hyaluronic acid filler that has been engineered to be firmer will last longer than hyaluronic fillers designed for flexibility.

Most patients won’t experience any pain after having dermal fillers. However, some people may find they have a little bit of soreness and/or mild bruising at the injection site. If you do experience any pain, bruising, or swelling, you can treat this with an ice pack.