Botox vs filler: what each one actually does

The short answer: neuromodulators (Botox, Dysport, Letybo) soften the signal between a nerve and a small muscle, so the skin above it stops folding as deeply. They treat lines caused by movement. Dermal fillers are a hyaluronic acid gel placed under the skin to replace volume that has been lost. They treat hollowing and lost structure.

If the line only appears when you move, that is usually a neuromodulator conversation. If it is there when your face is completely still, it is usually a volume conversation. Most of the decision is in that sentence.

What do neuromodulators actually do?

Neuromodulators are the family that includes Botox, Dysport and Letybo. All three are botulinum toxin type A. They work by reducing the release of acetylcholine at the junction between nerve and muscle, which temporarily softens how hard that muscle contracts.

When the muscle relaxes a little, the skin sitting on top of it stops folding as deeply. Over weeks, lines that were starting to stay put even at rest tend to soften. Done well, the result looks like you, a little less tired.

On timing, the Botox Cosmetic label states the effect typically begins one to two days after injection and increases in intensity through the first week (FDA label). At day 30 for frown lines, 80% of patients were rated none or mild by the investigator.

Which areas are FDA-approved?

Useful to know, because it tells you what questions to ask anywhere you go.

Botox Cosmetic holds four approved facial areas, with platysma bands added in October 2024. Dysport's cosmetic indication is frown lines in adults under 65 (FDA label). Letybo, approved in 2024, is frown lines (FDA label).

Off-label prescribing is lawful and often entirely appropriate. Masseter treatment and the lip flip are genuinely useful and neither is approved. The point is that you should be told which is which, and we tell you.

One more label detail. Botox Cosmetic's stated duration of three to four months applies to frown lines specifically, which is the area the trials measured.

What do dermal fillers do?

Dermal fillers are a different category entirely. Most modern fillers are hyaluronic acid, a sugar your body already produces, in a gel that holds its shape under the skin.

Filler does not relax a muscle and does not change expression. It restores structure that softens with time: the cheek, the temple, the jawline, the lips. You see early results immediately, though the final result settles at about two weeks.

Fillers are regulated as medical devices, and the FDA's approved uses for absorbable fillers in adults 22 and over are moderate to severe facial wrinkles and folds, plus augmentation of the lips, cheeks, chin and back of the hand (FDA).

Done thoughtfully, you look refreshed rather than altered. We dose conservatively and add at follow-up rather than starting big.

One real advantage of hyaluronic acid filler

It is adjustable. Hyaluronic acid can be dissolved with hyaluronidase, an enzyme that breaks it down within about 24 to 48 hours of action (Kroumpouzos and Treacy, JMIR Dermatology).

In practice that means two things. If you decide you want less, that is a conversation rather than a wait. And any practice injecting filler should keep hyaluronidase on site as a matter of course, which is a fair and easy question to ask. We do.

Biostimulators such as Sculptra and Radiesse work differently and are not dissolved this way, which is worth knowing when you compare the categories.

How do the two compare?

What does it cost?

Neuromodulators at our Williamsburg, VA practice start at $13 per unit.

Units are the honest way to price tox, because the amount needed varies by muscle and by person rather than by area. A first frown-line treatment uses a different number of units than a maintenance visit a year in, and we would rather quote you accurately than sell a flat package that fits nobody exactly.

Filler is priced per syringe, which is a different measure, so a side-by-side figure would compare two unlike things. Current starting prices are on the dermal fillers page, and your plan is confirmed at consultation.

Where do people mix them up?

Mostly around the eyes. Some lines there are caused by movement, which is neuromodulator territory. Some are caused by the cheek dropping and the under-eye hollowing, which is a volume question. Reading that correctly is most of getting a good result.

The other common mix-up is the lower face. Marionette lines and jowls usually read as a volume and structural question rather than a movement one.

One quiets a muscle. The other restores volume.

What we'll talk about at your consult

• What you are actually seeing, and whether it moves when you move.
• Your medical history, including any neuromuscular condition, and any allergy history. Dysport specifically is not used in anyone allergic to cow's milk protein, which is rarely asked about anywhere.
• Whether you are pregnant or breastfeeding.
• Current medications, including blood thinners, which affect bruising.
• Where your product is sourced, which you are welcome to ask us and anyone else.
• What a realistic result looks like, and what it will take to maintain it.

Can you have both?

Often yes, though usually not on the same day and not as a default. Doing one at a time makes it clear which treatment produced which change, and it lets us fine-tune at your two-week follow-up.

If what you are actually seeing is skin quality rather than muscle or volume, neither is the answer. That is a skincare routine and resurfacing conversation. Results vary, and the best plan is often smaller than people expect.

Book a consultation and we'll look at your face together and tell you honestly what's worth doing.