Botox vs. Dysport: what's actually different?

Botox and Dysport are often treated as interchangeable, and for most patients they produce nearly identical results. But there are meaningful differences that experienced injectors weigh when choosing between them — and understanding those differences helps you ask better questions at your consultation.

The basic science

Both are botulinum toxin type A — a purified protein that temporarily blocks the nerve signals that tell muscles to contract. When injected into specific facial muscles, the muscle relaxes and the overlying skin smooths.

The active ingredient is the same. What differs is the formulation, potency, and molecular behavior.

Dosing and units

Dysport units and Botox units are not interchangeable. Because Dysport is more dilute, it takes roughly 2.5–3 Dysport units to equal 1 Botox unit of effect. When providers quote you "20 units," they should specify which product — the costs look different on paper even when the actual treatments are priced similarly.

A common rule of thumb: if a provider typically uses 20 Botox units for your forehead, they'd use approximately 50–60 Dysport units for the same area. The total cost per treatment tends to be comparable once dilution is accounted for.

Onset and duration

Dysport typically kicks in a day or two faster — most patients notice results in 2–3 days versus 4–7 days for Botox. Duration is similar for both: 3–4 months on average, though this varies by individual metabolism, muscle mass, and treatment area.

Neither product definitively lasts longer than the other. Claims you'll see otherwise are usually based on small samples or individual variation.

Diffusion: the most clinically meaningful difference

Here's where the choice actually matters. Dysport has a tendency to spread slightly further from the injection site — called diffusion — compared to Botox. That can be:

An advantage in large treatment areas like the forehead, where wider spread can mean more even coverage with fewer injection points.
A disadvantage near the eyes and brow, where unintended spread can cause a temporary drooping eyelid (ptosis) if it reaches the levator muscle.

Experienced injectors account for this. In the hands of a skilled provider, Dysport and Botox produce equally natural-looking results. The diffusion difference matters most when selecting dosing points near sensitive structures.

Which one is right for you?

The short answer: let your provider guide the choice based on your anatomy and goals. Both products work. The more important variable is the injector's experience, not which brand is on the syringe.

Questions worth asking at your consultation:

"Which product do you use most often, and why?"
"Are you adjusting the dosing points based on the product's diffusion profile?"
"What does the unit-to-unit cost comparison look like for my treatment plan?"

A provider who can answer those questions clearly is the provider you want, regardless of which bottle they reach for.

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