What dermal filler is: what it does and what it doesn't

Dermal filler is a material, in the vast majority of cases a hyaluronic acid gel, injected into the tissue. It restores volume and support where they have diminished, or adds projection where the structure never had it.

That is the whole definition. Most of what else gets said about it comes from mixing it up with other procedures.

What matters to someone researching it isn't the definition but the limit: filler takes up space. It doesn't relax muscle, correct pigmentation, tighten loose skin or change the quality of the surface. If the problem isn't a lack of volume, filler is the wrong tool, and that's where much of the frustration with the procedure comes from.

What dermal filler is for

It does three things, and they're worth separating because each calls for different reasoning.

Restoring what was lost. Over time, the face's fat compartments shrink and shift, and the bone beneath them remodels. The face doesn't "fall" because of the skin alone. It loses the base that held it up. Restoring volume at support points gives back part of that structural support.

Projecting what was never there. A short chin, a poorly defined jawline, flat cheekbones. Nothing was lost here. It's a proportion that was always that way, and it can be adjusted.

Softening folds that are depressions. Nasolabial folds, the tear trough between the lower lid and the cheek, marks that cast a shadow. When the mark is a valley, filling the valley changes what you see.

Outside these three, be suspicious. If someone offers you filler for significant sagging, for skin texture or for dark spots, they're using the tool they have instead of the one the case calls for.

How dermal filler works

The most widely used material is hyaluronic acid, a molecule the body already produces that attracts and holds water. In the lab it's made into a gel, with cross-linking (the bonds between its chains) varying by purpose. A firmer gel supports and projects. A softer gel blends into areas of thin skin and movement.

The choice of product isn't a technical detail the patient can ignore: it determines whether the result looks natural or looks done. A stiff gel in an area of expression stiffens the movement. A soft gel at a support point supports nothing and disappears quickly.

The gel is injected with a needle or a microcannula, at planes and points defined during the assessment. It takes up space immediately, so part of the result shows right away, and then it integrates into the tissue over the following days, while swelling and small irregularities are still present. Over time, the body breaks it down.

There are materials other than hyaluronic acid. The distinction that matters most is this:

A biostimulator is not a filler, even though it's injectable and comes up in the same conversation. It doesn't fill. It provokes a response from the tissue. Many plans combine the two, each doing its own job.

Something that rarely gets said: the fact that hyaluronic acid is reversible is the most important safety feature of the procedure. If something goes wrong (too much volume, the wrong placement, a vascular complication), an enzyme called hyaluronidase dissolves the product. Permanent material has no undo button. That's the main reason permanent materials have all but disappeared from the hands of practitioners who work with sound judgment.

What's the difference between Botox and filler

It's the most common question, and the answer is short: they act on different things.

• Botulinum toxin acts on muscle, reducing contraction. It's for lines that appear when you make an expression: forehead, between the brows, around the eyes.
• Filler acts on volume. It's for depressions, lost projection and lack of support.

A test at home settles most cases: stay still, with no expression, in front of the mirror. Whatever disappears when your face is relaxed is toxin territory. Whatever stays there, still marked, tends to be filler territory, or neither.

They don't compete. A good plan often uses both, because the face has both problems.

Which areas it's used on

The most commonly treated areas are the cheekbones, temples, chin, jawline, nasolabial folds, lips, the nose and the under-eye area.

One observation changes how you should read that list: the area of the complaint isn't always the area of treatment. It's one of the principles of how we work here: we assess the whole face before treating the complaint. Someone bothered by their nasolabial folds often has lost support in the midface, and the fold is the consequence that became visible. Filling only the fold gives a worse result than restoring the support whose loss created it.

How long filler lasts in the face

It depends on three factors, and none of them is the same for any two people: the area treated, the product used and the metabolism of the person receiving it.

An area with a lot of movement, such as the lips, uses up the product faster than a support area, which stays relatively still. A faster metabolism breaks it down faster. That's why the honest answer to "how long does it last" is a wide range, given at the assessment, for that specific case, not a number from a website.

A detail almost nobody mentions: the loss isn't an event, it's a curve. The product diminishes little by little, and the face follows little by little. Hardly anyone notices the day it "ran out". What usually happens is they look at an old photo and see the difference.

If you want to understand this part in depth, it has its own article, linked at the end of this page.

What are the risks of dermal filler

The common events are local and temporary: swelling, bruising, tenderness and small irregularities in the first few days.

The serious risk is different and deserves to be named: vascular occlusion. If the product is injected into a blood vessel or compresses one, blood stops reaching the tissue that vessel supplies. The consequences range from skin necrosis to, in specific areas, damage to vision. It's rare, and it's the reason this procedure demands knowledge of anatomy. Not injection technique. Anatomy.

There are also risks that come not from the product but from where it was done: material not registered with Anvisa, injection by someone without the qualification to do it, and no rescue plan when something goes wrong.

The FDA maintains a specific warning against so-called "needle-free" devices, pressure pens sold for injecting filler, because of the risk of serious injury. If you're offered one, the answer is no.

Safety

Assessment with Doppler ultrasound is part of the procedure here, and not as a marketing differentiator.

• Before, to map the anatomy of that specific face and to identify material from previous treatments. Old product in an unknown location changes the entire plan, and it's more common than people think, because almost nobody can say what they received, where, and from whom.
• After, to confirm there's no compression of a vein or artery.

Vascular pathways vary from person to person. An anatomy textbook shows the average. Doppler shows that face. It's the difference between working with knowledge and working on assumption.

What makes up the cost

We don't publish prices, because there's no such thing as "the price of dermal filler". There's the price of a specific plan for a specific face.

What goes into it:

• Amount and type of product, which depend on the area and the goal.
• Complexity of the case. A face with previous filler of unknown origin needs more assessment and more care than an untreated one.
• What comes with the procedure: assessment, ultrasound, follow-up visit, and the ability to deal with a complication if one happens.

That last item is the one most often ignored when comparing prices. Cheap usually means cheap because it doesn't include the structure for when something goes wrong.

When we advise against it

• When the complaint isn't about volume. Dark spots, texture, significant sagging and expression lines don't respond to filler. Filling there gives you a fuller face with the same problem.
• When the case is surgical. Advanced sagging isn't solved with volume. Adding product to a face that needs repositioning makes the result worse. In these cases we refer patients to a partner surgeon, and we say so at the assessment, not after three sessions.
• Before understanding what's already in the face, when there's been previous filler of unknown origin.
• When there's an active infection in the area to be treated, or ongoing inflammation.
• When expectations don't match what the procedure does. An edited photo as a reference, a request to change facial identity, or more volume than the face can hold.
• Pregnancy and breastfeeding. An elective procedure waits.

Frequently asked questions

How much does dermal filler cost?

We don't quote prices, because the number only exists once the plan is defined: area, product, amount. Any price given before the assessment is a guess or bait.

How long does filler last in the face?

It varies by area, product and metabolism. Areas with a lot of movement use it up faster than support areas. The realistic range for your case comes out of the assessment.

Does dermal filler hurt?

Most products already contain an anesthetic, and a topical anesthetic is applied beforehand. The most common report is discomfort, not pain, and it varies a lot by area. The lips are more sensitive.

Is filler permanent?

Hyaluronic acid isn't: the body breaks it down over time, and it can be dissolved with hyaluronidase if needed. Permanent materials exist, and it's precisely because they're permanent that they've all but disappeared from responsible practice.

How long until I see the final result?

Part of it shows immediately. The real result can be judged once the swelling resolves and the product integrates, which takes days, not months. Judging your face the next day means judging swelling.

Does filler make the face look puffy or artificial?

When that happens, it's almost always too much volume or product in the wrong plane, not a feature of the procedure. Here we measure quality by what the result preserves (movement, expression, identity), not by how much it changes.

Can I get filler and toxin in the same session?

Yes, and it's common, because they treat different things. The order and the distribution are part of the plan.

Does filler migrate?

It can shift, and there's usually a cause: a product unsuited to the area, the wrong injection plane, or more volume than the tissue can hold. It's one of the reasons we assess with ultrasound before touching a face that has already had product.