Hyaluronic Acid: What It Is, How It Works, Duration, Risks, Results, and Myths (Complete Scientific Guide 2026)

But what is it really? To understand it in a simple way, imagine a tiny sponge that lives naturally in your skin. Its main job is to attract water and retain it. Thanks to this sponge, your face looks hydrated, elastic, firm, and with that plump volume so characteristic of youth.

Hyaluronic acid is not a synthetic or strange chemical that we introduce into your body; it is a molecule that you produce naturally. In fact, more than half of all the hyaluronic acid in your body is concentrated in your skin, filling the space between cells and acting as its cushioning mat.

As we age, our internal hyaluronic acid factory begins to slow down its production rate. From the age of 25 or 30, not only do we produce less, but what we already have is destroyed faster due to natural wear and tear and factors like the sun or stress.

• It is as if the skin's natural sponge is drying and shrinking. By losing this hydration and support "cushion":
• The skin becomes thinner, drier, and less elastic.
• The first expression lines and wrinkles appear.
• Facial fat compartments descend, making features look more droopy, sad, or tired.

It is a completely normal biological process, but thanks to modern aesthetic medicine, today we can restore this lost support precisely and safely.

When I evaluate a patient in my consultation, I always insist that hyaluronic acid is not only used to "fill wrinkles." It is a three-dimensional design and support tool that allows us to harmonize the face globally.

Here are clear examples of what we can achieve in different areas:

• Lips: The main goal is not always to add volume. With the right product we can contour a border that has faded over the years, correct birth asymmetries, rehydrate dry lips, or restore their natural plumpness in a very sophisticated way. You have all the details in our Lip fillers section.
• Cheekbones: They act as the "hangers" of the face. By restoring volume in the cheekbone and cheek area, we achieve an upward traction effect that helps lift sagging tissues indirectly.
• Chin: Projecting a chin subtly forward balances the entire profile of the face, especially if you have a retracted chin.
• Jawline: Defining the jawline helps frame the face, stylizes the neck, and disguises initial sagging in the jowl area.
• Dark Circles: We camouflage the hollow of the tear trough, eliminating the dark shadow that makes us look tired even after a good night's sleep.
• Folds: We soften the lines that run from the nose to the mouth (nasolabial folds) or the corners of the lips that drop down giving an angry look (marionette lines).
• Nose (Nonsurgical Rhinoplasty): We correct small deviations of the bridge or lift the tip of the nose subtly without having to go through an operating room.

Injectable hyaluronic acid has a dual mechanism of action that I, as a doctor, find fascinating:

This means that, as the injected product is slowly reabsorbed over the months, it is replaced in part by your body's own collagen, improving skin firmness in the long term.

In order for hyaluronic acid to last in your body and perform its function, its chains are linked in the laboratory through a process called cross-linking (which consists of creating a three-dimensional mesh or network). Depending on how dense that network is, we obtain different consistencies of the gel (what doctors call rheology):

• G' (Elastic modulus) or "Support Gels": These are firm and compact gels that do not deform easily. I use them in deep planes, directly on the bone, to simulate the structure of the cheekbones or chin.
• Cohesivity or "Integration Gels": This is the ability of the gel molecules to stay together. In areas of high gesticulatory movement, such as the lips or around the mouth, we need a product with high cohesiveness so that it moves with your lip when speaking, smiling, or kissing, without fragmenting or looking stiff.
• Viscosity or "Fluid Gels": These are very soft and light gels, almost liquid. They are used in superficial planes to hydrate the skin without adding volume (such as in mesotherapy) or to treat extremely delicate areas such as dark circles.

In evidence-based aesthetic medicine, it is a mistake to give an exact duration figure. If a professional promises you that hyaluronic acid will last exactly 12 months, doubt them. The real duration is variable and depends on individual factors:

• The facial area: In areas with a lot of mobility (like lips or mouth), the product wears out physically sooner due to continuous gesticulation (usually lasts 6 to 12 months). In static areas (such as temples or chin), the support can exceed 12 or 18 months.
• Metabolism: Each person destroys the product at a different biological rate using their own body enzymes (hyaluronidases).
• High-intensity exercise: High-performance athletes metabolize the product faster due to increased metabolism and body temperature.
• Smoking: Smoking introduces free radicals into tissues that degrade the extracellular matrix and the injected gel at an accelerated rate.
• The sun: Repeated solar exposure without protection damages collagen fibers and accelerates skin hydration loss.

I want to talk to you about the safety of the treatment with complete transparency. Hyaluronic acid is one of the safest injectables that exist thanks to its biocompatibility, but it is still a medical procedure and, as such, presents risks that you should know:

• What is common (mild): After the session it is completely normal to experience some swelling or small bruises (bruising) at the injection points. They resolve on their own in a few days and you can camouflage them with makeup from the next day.
• Tyndall Effect: If the product is injected in too superficial a plane, light can reflect off it giving a bluish or grayish tone to the skin. It sometimes occurs in dark circles and is solved by dissolving that small amount.
• Delayed inflammatory nodules: Small hard lumps that appear months after treatment. They are often caused by very slow-growing bacteria that create a protective layer around the gel (biofilm). They are effectively treated with antibiotics and by dissolving the area.
• Vascular occlusion (the serious risk): Occurs if the product is accidentally injected into an artery, blocking the blood supply of the tissue. It is a very rare but serious complication, since if it is not acted upon quickly, the lack of oxygen can cause necrosis (tissue death).

The greatest success of my work is that you are seen with a "great face", more rested and fresh, but nobody notices that you have had a treatment. To achieve this, I follow three non-negotiable rules in my consultation:

• Respect your unique anatomy: Not all lips or cheekbones fit well on all faces. I seek harmony and natural proportion of your features, never creating standardized faces.
• Less is more: It is preferable to perform the treatment progressively. Often I prefer to do a soft initial session and touch up in two weeks if necessary, allowing the tissue to adapt gradually.
• Avoid over-correction: The abuse of fillers continuously saturates the tissue and ends up distorting natural facial features.

Your face is your presentation letter and you only have one. If you are thinking of having this treatment, I highly recommend that you investigate these points:

• Medical qualification: Make sure the professional is a doctor with specific and accredited training in aesthetic medicine or dermatology.
• Technology and safety protocols: Make sure they know in detail the safety and complication management protocols and if they have hyaluronidase in the clinic to resolve any incidence.
• Transparency: A good professional should perform a comprehensive medical evaluation before injecting, explain the alternatives, and refuse to perform a treatment if they consider that it will harm the naturalness of your face.

Hyaluronic acid is undoubtedly one of the most valuable tools in today's aesthetic medicine to help you age with elegance, freshness, and naturalness. But always remember that the success of the treatment does not lie in the product that comes inside the syringe, but in the hands, diagnosis, and aesthetic criteria of the doctor who injects it.

• Kablik J, Monheit GD, Yu L, Chang G, Gershkovich J. Comparative physical properties of hyaluronic acid dermal fillers. *Dermatol Surg*. 2009;35 Suppl 1:302-312. doi:10.1111/j.1524-4725.2008.01046.x
• Wang F, Garza LA, Kang S, et al. In vivo stimulation of de novo collagen production caused by cross-linked hyaluronic acid dermal filler injections in photodamaged human skin. *Arch Dermatol*. 2007;143(2):155-163. doi:10.1001/archderm.143.2.155
• DeLorenzi C. New consensus on hyaluronidase use in managing adverse events from hyaluronic acid filler. *Aesthet Surg J*. 2017;37(Suppl 1):S17-S25. doi:10.1093/asj/sjw224