Understanding Dermal Fillers: What They Are & How They Work

Aimee Brigham|April 9, 2026

If you’ve ever visited a med spa about the lines around your nose and mouth — sometimes called “parentheses lines” — and were told Botox wasn’t the best option, you’re not alone. Dermal fillers and neuromodulators work in fundamentally different ways, and understanding the difference is the first step toward natural, balanced results.

What Are Dermal Fillers?

Dermal fillers, especially those made with hyaluronic acid (often called H.A.), are popular treatments that help smooth deeper lines, restore lost volume, and enhance facial features.

Although the name might sound a bit intimidating, hyaluronic acid is something your body naturally produces. It is found in your skin and helps keep it hydrated, smooth, and firm. One of its main benefits is that it holds onto water, which gives your skin a plump, healthy appearance and supports its structure.

Hyaluronic acid — a naturally occurring molecule that supports skin hydration and structure

As we get older, our bodies make less hyaluronic acid. This can make the skin feel thinner, drier, and less firm, leading to more visible lines and a loss of structure in some parts of the face. Hyaluronic acid fillers are made to replace what your skin has lost over time. They are a smooth, gel-like material that is gently injected under the skin at different depths, depending on the area.

Hyaluronic acid fillers are precisely administered using fine-gauge syringes

Because these fillers work so well with the body, they have mostly replaced older options like collagen fillers, which are now rarely used or recommended.

Why Patients Choose HA Fillers

Results are visible immediately. There is no major downtime, so many patients return to work the same day. And if needed, hyaluronic acid fillers can be reversed with an enzyme called hyaluronidase.

78.5%

Moderate to significant improvement at 8 months

80.4%

Visible improvement on photographic evaluation

How They Compare

Dermal Fillers vs. Neuromodulators

Many patients wonder if they should choose dermal fillers or neuromodulators like Botox or Dysport. Both can help reduce wrinkles, but they work in fundamentally different ways.

Neuromodulators relax the muscles that cause dynamic wrinkles — the lines formed from repeated facial expressions. Frown lines between the eyebrows and crow’s feet around the eyes are classic examples.

Dermal fillers address volume loss and changes in facial structure. Lines around the nose and mouth, or hollow areas under the eyes, are caused by lost volume, not muscle movement. Research has shown that HA injectable fillers support the extracellular matrix in the dermis and help stimulate fibroblast activation and collagen production.

Many patients choose to use both Botox and dermal fillers for total

Many patients choose to use both Botox and dermal fillers for total rejuvenation, since each one targets a different underlying process of facial aging.

Full-Face Balance vs. Spot Treating

One of the most significant advancements in aesthetic medicine has been the shift away from treating isolated areas toward a more holistic, full-face approach. In the past, it was common to inject filler directly into a wrinkle or fold. While this could provide temporary improvement, it often failed to address the root cause and sometimes led to unnatural results.

Today, we understand that the face functions as a connected system. Volume loss in one area affects the appearance of another:

How Aging Connects Across the Face

Flattened cheeks can deepen nasolabial folds. Changes in the mandible can exaggerate lower face aging. Hollow temples can make the eyes look more tired. A recessed chin can throw off facial harmony. By restoring volume in multiple strategic areas, injectors can create lift, balance, and harmony across the entire face.

Before and After: Full-face approach restoring volume and balance across the midface

Technique & Philosophy

How to Avoid Looking Overfilled

The fear of looking “overdone” or unnatural is one of the most common concerns surrounding dermal filler, understandably so. The key to avoiding the overfilled outcome lies in both technique and philosophy. At Aluma, Dr. Brigham takes a moderate, strategic approach to help patients look refreshed and balanced, not overdone.

Before and After: A strategic, moderate approach that refreshes without looking overdone

1 - Enhance Structure & Support

Restore facial volume and support that naturally decreases over time. Focusing on main support areas like the lateral cheek and jaw angle can improve multiple concerns simultaneously, reducing the total amount of product needed.

2 - Maintain Natural Proportions

A skilled injector follows natural beauty ratios. The goal is not to change your appearance, but to help you look like a younger, more refreshed version of yourself. Our sense of what is beautiful is often linked to the golden ratio — approximately 1.618.

3 - Use the Right Product for the Right Area

There are 7+ filler types designed for different areas. The main differences are HA concentration, particle size, molecular weight, and crosslinking technology. Using the wrong product for a given region can compromise the result.

4 - Choose an Experienced Injector

A qualified injector knows facial anatomy, understands where significant blood vessels are, and has an eye for balance. At Aluma, all injectable treatments are performed by Nathaniel S. Brigham, MD.

Every treatment at Aluma begins with a thorough consultation and treatment plan

Where Fillers Are Used

Areas Commonly Treated with Dermal Fillers

Dermal fillers are incredibly versatile and can be used to enhance or restore multiple areas of the face.

Common treatment areas — lips, tear troughs, cheeks, chin, and jawline

Cheeks

The cheeks are typically the first facial region to lose volume. Restoring midface volume can elevate the entire face and improve the appearance of jowls, nasolabial folds, and the undereye area.

Lips & Upper Lip Lines

The cheeks are typically the first facial region to lose volume. Restoring midface volume can elevate the entire face and improve the appearance of jowls, nasolabial folds, and the undereye area.

Under Eyes

Treatment focuses on smoothing the tear trough after ensuring adequate mid-face support. This delicate procedure requires advanced technical skill and understanding of filler properties.

Nasolabial Folds

The most effective approach is usually to restore midface volume first. By lifting the cheeks, the skin drapes less, reducing fold depth naturally before any direct treatment.

Jawline & Chin

Firmer fillers can rebuild structure, define the jawline, improve chin shape, and reduce sagging. Treatment targets the jaw angle and prejowl area for a more balanced profile.

Temple

Temple filler restores volume to hollowed areas, can lift the eyebrows, smooth the temple-to-forehead transition, and gently open the eyes for a more youthful appearance.

Real Patient Results

Balanced, Natural Rejuvenation

before and after photo of woman who had dermal filler for her undereyes

Before & After: Under-eye and midface volume restoration

Before & After: Full-face balance addressing nasolabial folds and midface volume

Understanding Filler Science

Understanding Filler Types & Properties

Rheology — the study of how materials flow and change shape under stress — is an extremely important component of achieving natural results. Different fillers have different physical properties, and matching the right product to the right area is essential.

G-Prime (Firmness)

The elastic modulus, or G′, measures how firm a material is and how well it resists being deformed. Firmer gels like Juvederm’s Volux have higher G′ values and are used deep against the bone to shape areas such as the chin. Softer fillers with lower G′, like Volbella and Ultra, feel more natural and are better suited for the lips and the area around the eyes.

Cohesivity

Cohesivity measures how well a dermal filler holds together after injection. Fillers with higher cohesivity stay more intact when pressed, so they can lift and shape larger areas more effectively. Softer fillers spread more easily, making them ideal for smoothing fine lines and blending into the skin.

Swelling Factor

The swelling factor describes how much a filler can absorb water and expand. For the undereye area, a low-swelling filler avoids an unnatural, puffy look. A bit of swelling, however, can help add volume when treating the mid-face or temples. More crosslinking usually makes the gel firmer and reduces swelling.

How Long Do Dermal Fillers Last?

The longevity of dermal fillers depends on several factors, including the type of filler, the degree of cross-linking, the treatment area, and an individual’s metabolism. Areas with more movement, such as around the mouth, may see fillers break down more quickly.

10–18 mo

Typical HA filler duration

Periodic

Maintenance for sustained results

The Evolution of Dermal Fillers

Dermal fillers have advanced significantly since the first FDA-approved filler — bovine collagen — arrived in the 1980s. That product required allergy testing and had limitations on where it could be used.

The introduction of hyaluronic acid fillers in the early 2000s transformed aesthetic medicine. Since then, advancements have led to a variety of specialized fillers, each designed with specific properties for targeted areas and outcomes. Today’s fillers offer greater refinement, predictability, and versatility, allowing for highly customized treatments that deliver natural, balanced results.

Frequently Asked Questions

What are Dermal Fillers?
Dermal fillers are injectable treatments, most commonly made with hyaluronic acid, that help restore lost volume, soften deeper lines, and enhance facial features. Hyaluronic acid is naturally found in the body and helps support hydration, smoothness, and facial structur
What is the difference between fillers and Botox?
Botox and Dysport relax the muscles that cause expression lines, while dermal fillers restore volume and support in areas affected by facial aging, such as the cheeks, under-eyes, lips, and deeper lines around the nose and mouth.
What ares can be treated with dermal fillers?
Dermal fillers can be used in the cheeks, lips, under-eyes, smile lines, chin, jawline, and temples. At Aluma, treatment is customized to the patient’s facial anatomy and goals rather than taking a one-size-fits-all approach.
Can fillers help with under-eye hollows and smile lines?
Yes. Dermal fillers can soften under-eye hollows by restoring volume and smoothing shadows beneath the eyes. They can also improve smile lines, often by restoring midface support first so the cheeks help lift and soften the fold more naturally.
How long do Dermal Fillers last?
In general, hyaluronic acid fillers last about 10 to 18 months. Longevity depends on the filler type, the treatment area, and individual metabolism. Many patients choose periodic maintenance to sustain results over time.
Will fillers make me look unnatural?
When used thoughtfully, dermal fillers restore balance and support without creating an overdone look. Natural results depend on proper technique, using the right product in the right area, and taking a full-face approach. At Aluma, Dr. Brigham takes a moderate, strategic approach.
Are dermal fillers safe?
Dermal fillers are generally considered safe when performed by a skilled injector with a strong understanding of facial anatomy. As with any injectable, complications are possible, which is why injector experience matters. At Aluma, all treatments are performed by Nathaniel S. Brigham, MD.
What is the downtime after treatment?
Most patients return to normal activities the same day. Mild swelling and tenderness for a day or two can happen, and some patients may also notice slight bruising at the injection site.

Ready for a Personalized Consultation?

Dr. Brigham will assess your anatomy and goals to create a customized treatment plan designed around you.

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Aimee Brigham

As co-owner of Aluma Aesthetic Medicine and a Comcast RISE recipient, Aimee draws on her two decades of experience as a Speech Pathologist, applying response-to-intervention frameworks to bring evidence-based decision-making to every aspect of patient care at Aluma.