When looking into forehead Botox, you often see comments like, 'Dysport shows results faster and looks more natural.' It is true that when looking purely at onset time, price, and duration, Dysport is an attractive option. However, some accompany this with the advice to 'only get it if you don't have to worry about blepharoptosis (drooping eyelids).' Let's break down what this means and whether blepharoptosis is the actual standard you should be looking at.

While both are 'botulinum toxins', they work in slightly different ways

Both Botox (Allergan/AbbVie) and Dysport (Galderma) are Botulinum toxin type A*. They share the same mechanism of temporarily blocking signals from the nerves to the muscles to relax them. Consequently, they last for a similar duration (about 3 to 4 months).

The key difference lies in the size of the protein molecules and the resulting 'diffusion radius.' Because Dysport has a smaller and lighter molecular structure than Botox, it has a tendency to spread wider, even when the same amount is injected into the same spot.

* Botulinum toxin type A: A purified neurotoxin produced by Clostridium botulinum. It blocks the release of acetylcholine at nerve endings to prevent muscle contraction. Botox, Dysport, Xeomin, and Nabota all belong to this type A category.

Dysport spreads faster and wider than Botox

Dysport has two main advantages. First, rapid onset. While Botox takes 3 to 7 days to kick in, Dysport shows visible results in just 1 to 3 days. Second, a wider diffusion radius*. When injected at a single point, Botox works within a 3 to 5 mm radius, whereas Dysport spreads out 5 to 10 mm.

* Diffusion radius: The distance botulinum toxin spreads from the injection site to the neighboring muscle fibers. This varies depending on molecular size and protein structure. A narrow radius allows for precise relaxation of a targeted spot, while a wide radius relaxes a larger area evenly at once.

When you want to evenly relax a broad muscle like the frontalis (forehead muscle) and desire quick results, Dysport’s 'fast and wide' spread becomes a major advantage. It is excellent for minimizing injection points and creating a natural, even distribution.

This 'wide spread' can be a drawback for those with muscle dependency

That same 'wide spreading' characteristic can work against you if you depend heavily on your forehead muscles to open your eyes. The strategy of 'targeting only the upper forehead while preserving the sides' (which we explored in Part 3 of our series) is difficult to execute precisely with Dysport. Even if injected only at the top, the product spreads 5 to 10 mm downward and outward, eventually reaching the sides of the forehead and just above the eyebrows.

This is why practitioners often say, 'It’s best to get Dysport only if you don’t have to worry about drooping eyelids.' To be precise, it means 'for those who rely heavily on their forehead muscles, Dysport’s high diffusion increases the risk of pseudoblepharoptosis (temporary heaviness or drooping of the eyelids).'

It is unrelated to true blepharoptosis — muscle dependency is the real criteria

This is a common point of confusion. The accurate standard isn't 'you shouldn't get Dysport if you have blepharoptosis,' but rather 'be cautious with Dysport if you rely heavily on your forehead muscles to open your eyes.'

True blepharoptosis (a structural weakness of the levator palpebrae superioris muscle itself) cannot be caused by Botox or Dysport. Neither of these products comes into direct contact with that muscle. What we actually worry about is pseudoblepharoptosis (eyelid heaviness due to relaxed forehead muscles), which can happen with any toxin if you have a strong dependency pattern. Dysport simply carries a slightly higher risk in these specific cases due to its high diffusion.

Which product is right for you?

We choose the appropriate product by combining your self-assessment results with your natural facial expressions. Here is a summary table:

There is no absolute 'right' choice between Dysport and Botox. The clinical standard is to gauge your level of forehead dependency first, and then select the product accordingly. While the final choice should always be made during a consultation with your doctor, knowing these standards beforehand will make your decision-making much clearer and easier.

Frequently asked questions

Q. Is Dysport a less effective product than Botox?

A. Not at all. Dysport is actually a better fit for areas that require quick results and an even distribution, such as the entire forehead, the space between the brows, or larger muscles like the calves. The challenge arises in cases where we need to 'precisely anesthetize only one specific spot while leaving the surrounding areas untouched.' A forehead-muscle-reliant type is exactly one of those cases.

Q. What should I do if Dysport has caused pseudoptosis (drooping eyelids)?

A. It is the same as when it happens with Botox. It will recover naturally if you wait for about 3 to 4 months. For your next treatment, we can either switch to Botox or, if you continue with Dysport, adjust by reducing the dosage by more than half and only injecting the upper forehead.

Q. Is it okay to mix and use these two products during the same procedure?

A. In clinical practice, we usually stick to one product for a single session. Using different products on different areas can lead to asymmetric results because their onset times and diffusion rates may vary. It is much safer to find the product that works best for you by trying one product during this session, and perhaps a different one during your next visit.

Q. What is the difference in the diffusion spread (the area it covers from a single injection point) between Dysport and Botox?

A. When injected, standard Botox acts within a 3 to 5mm radius of a single point, whereas Dysport spreads wider, from 5 to 10mm. While this spread is an advantage when you want to evenly relax a broader muscle, we approach it with extra care and precision when targeting a single, highly specific spot.