How are Botox and Dysport different?
Botox Cosmetic and Dysport are both botulinum toxin type A and work the same way. They differ in formulation, in how their units are measured, in the areas the FDA has approved, and, in some studies, in how quickly they start. Units of one cannot be converted into units of the other, so an injector plans each product on its own terms.
The same active ingredient
Botox Cosmetic (onabotulinumtoxinA) and Dysport (abobotulinumtoxinA) are both botulinum toxin type A. Each label describes its product as an acetylcholine release inhibitor and a neuromuscular blocking agent. Both relax the injected muscle by blocking the nerve signal that tells it to contract, and both wear off as the nerve recovers. the FDA approved onabotulinumtoxinA as Botox Cosmetic for glabellar lines in 2002 (source, verified ); Dysport's initial U.S. approval was in 2009 (source, verified ).
The generic names differ because each product is a distinct preparation, made by a different company with a different process and measured on its own scale. The rest of this article is about what those differences mean in practice.
Formulation
Both are supplied as a powder that the injector dissolves in saline. Botox Cosmetic is a neurotoxin complex, the active molecule bound to accessory proteins, with human albumin and sodium chloride as its other ingredients. the Botox complex is about 900 kDa in size, while the neurotoxin molecule itself that does the work is 150 kDa (source, verified ). Dysport is also a complex, of the neurotoxin with hemagglutinin and non-hemagglutinin proteins, and contains human albumin and lactose. Dysport may contain trace amounts of cow's milk protein and is contraindicated in people with a known hypersensitivity to it (source, verified ).
Whether the accessory proteins matter clinically is debated. Xeomin, a third product, is purified down to the bare neurotoxin without them. The evidence summarized below suggests the proteins do not change how far the product spreads once injected.
Units are not interchangeable
This is the difference that matters most to a patient reading a treatment plan. the Botox Cosmetic label states that its units are specific to its own preparation and assay method, that the product is not equivalent to other botulinum toxin products, and that its units cannot be compared to or converted into units of any other botulinum toxin product (source, verified ). the Dysport label says the same of its own units, which are not interchangeable with other preparations of botulinum toxin products (source, verified ).
The labeled doses show the gap. the labeled Botox Cosmetic dose for glabellar lines is 20 Units, given as five injections of 4 Units (source, verified ). the labeled Dysport dose for the same lines is 50 Units, given as five injections of 10 Units (source, verified ). a ratio of 2 to 3 Dysport units per Botox unit has been proposed in several publications, with about 2.5 to 1 often assumed in aesthetic use, but no conversion ratio has been formally established (source, verified ).
So “20 units” of one brand and “50 units” of the other can describe a comparable treatment of the same muscle. A unit count is meaningful only alongside the brand name, and a per-unit price is meaningful only in the same way.
Spread
Once injected, a neuromodulator spreads a short distance from the needle tip. Patients sometimes hear that Dysport “spreads more”. The research is more careful than that.
in sweat-gland studies that injected the two products at the same volume and at a range of unit ratios, the area of reduced sweating was larger with Dysport in 93% of comparisons (source, verified ). But when the same dose was injected with the same technique there were no differences in diffusion between products, and the presence of complexing proteins in a preparation does not reduce migration (source, verified ). The likely explanation is that most comparisons used more Dysport units than Botox units, and more drug spreads further.
The practical point: spread is governed by how much is injected, in what volume, and exactly where. Those are the injector’s decisions with either product. A careful plan for the brow, for example, keeps the dose away from the muscle that lifts the eyelid regardless of brand.
Onset
a 2020 systematic review of 42 publications found Dysport's onset most often reported within 2 to 3 days, and as early as 24 hours in two studies (source, verified ). in several small comparative studies, a higher proportion of patients reported onset with Dysport than with Botox at time points up to day 5, usually at a 2.5 to 1 unit ratio; the review was sponsored by Dysport's manufacturer (source, verified ). For comparison, in the Botox Cosmetic glabellar line studies, 74% of treated subjects were rated as responders by investigators at day 7, against 6% with placebo (source, verified ).
The honest summary is that both products produce a visible change for most people within the first week, and Dysport may be a day or so ahead in some people. Onset and duration in detail.
FDA-approved areas
Botox Cosmetic is approved in adults for moderate to severe glabellar lines, lateral canthal lines, forehead lines and platysma bands (source, verified ). Dysport's only cosmetic approval is for moderate to severe glabellar lines in adults under 65 (source, verified ). Treating forehead lines or crow’s feet with Dysport is therefore off-label in the United States, which a prescriber may order but should tell you about.
Both products carry the same FDA boxed warning about the effect spreading beyond the injection site, and both labels list the same core contraindications: a known allergy to any botulinum toxin product or formulation component, and infection at the injection site. Dysport adds cow’s milk protein.
Duration
The labels describe the two products in the same range. Neither label claims a longer effect than the other, and the two have not been compared for duration in a single trial at matched doses.
Botox Cosmetic: Botox Cosmetic reduced glabellar line severity for up to 120 days in its registration studies (source, verified ). Dysport: the Dysport label says its clinical effect may last up to four months and that it should be given no more frequently than every three months (source, verified ).
Which is right for you
Which products a given practice stocks varies, and the choice among them is made with the prescriber. Reasons to prefer one over the other include which areas you want treated, how you responded to a product before, and any allergy that rules one out. Both are prescription drugs ordered by a delegating prescriber, and in Arizona both require a Good Faith Exam for a new patient. Arizona’s rules for nurse injectors. The patient guide to neuromodulators.
Sources
- BOTOX Cosmetic (onabotulinumtoxinA) for injection, Prescribing Information (revised 10/2024) , AbbVie Manufacturer Accessed
- DYSPORT (abobotulinumtoxinA) for injection, Prescribing Information (revised 1/2023) , U.S. Food and Drug Administration Regulator Accessed
- Pharmaceutical, Biological, and Clinical Properties of Botulinum Neurotoxin Type A Products , Drugs in R&D (PubMed Central) Peer-reviewed Accessed
- Onset and Duration of AbobotulinumtoxinA for Aesthetic Use in the Upper Face, A Systematic Literature Review , Journal of Clinical and Aesthetic Dermatology (PubMed Central) Peer-reviewed Accessed
- Treatment of glabellar lines with Botox (onabotulinumtoxinA), Development, insights, and impact , Medicine (PubMed Central) Peer-reviewed Accessed
Questions readers ask
Is Dysport weaker than Botox because it needs more units?
No. The two companies measure units with different assays, so the numbers are on different scales. More Dysport units for the same muscle does not mean more drug or a weaker product; it means a different ruler.
Can I switch from Botox to Dysport, or back?
Yes. The plan is built fresh for the new product rather than converted from the old one. Tell your injector which product you had, roughly how much, and when, so the timing and dosing can be judged.
Does Dysport spread more than Botox?
Studies disagree, and the differences they found depended on the dose and volume injected as much as on the product. In practice, how far a neuromodulator spreads is controlled by dose, volume and placement, which is the injector's job with either brand.
Does Dysport work faster?
Some small comparative studies reported onset a little earlier with Dysport, by a day or so. The difference is modest, and the largest review of it was sponsored by Dysport's manufacturer. Both products produce a visible change within the first week for most people.
If I am allergic to milk, can I have Dysport?
Dysport may contain trace amounts of cow's milk protein, and its label lists a known hypersensitivity to cow's milk protein as a contraindication. Tell the prescriber at the Good Faith Exam; Botox does not carry this contraindication.
Is one cheaper than the other?
Per-unit prices are not comparable between brands, because the units are not the same size. Compare the total cost of your treatment plan, not the price per unit.
Revision history (1)
- update First version, written from FDA prescribing information and peer-reviewed literature Editorial team