Botox to Dysport Conversion Calculator
Convert Botox units to Dysport units (and vice versa) using standard clinical conversion ratios. An educational reference for patients switching products or comparing treatment plans.
Botox and Dysport — same family, different units
Botox and Dysport are both botulinum toxin type A products — they work through the same mechanism, targeting the same neuromuscular junction to temporarily relax muscles. However, they are manufactured by different pharmaceutical companies using different production processes, resulting in slightly different molecular complexes and, critically, different unit measurement systems.
The "unit" of each product is defined by that manufacturer's proprietary bioassay. One Botox unit is defined as the amount of toxin that causes 50% lethality in mice (the LD50) in Allergan's assay. Dysport uses a similar method, but because the assay conditions differ, the unit values come out differently. The result: you need more Dysport units than Botox units to achieve the same clinical effect.
The most widely cited conversion ratio in clinical literature is 1 unit Botox = 2.5 to 3 units Dysport. Most practitioners start at 2.5:1 when switching patients between products. Some use 3:1 as a more conservative conversion to avoid under-dosing. Studies comparing the two products generally show equivalent efficacy and safety at these conversion ratios.
Patients sometimes switch products due to price differences, availability, or practitioner preference. Understanding this conversion helps patients have informed conversations with their clinicians about whether a product change is appropriate.
Reference: FDA prescribing information — Botox/Botox Cosmetic (onabotulinumtoxinA).
Conversion formula
Frequently asked questions
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The most widely cited conversion ratio is 1 unit of Botox = 2.5 to 3 units of Dysport. Most practitioners use a 1:2.5 ratio as a starting point for new patients switching from Botox. Some practitioners prefer 1:3, particularly for larger muscle groups. The exact ratio that achieves equivalent clinical effect varies between patients and treatment areas. Units of different botulinum toxin products are NOT interchangeable and should never be directly substituted unit-for-unit.
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Botox (onabotulinumtoxinA) and Dysport (abobotulinumtoxinA) are both type A botulinum toxins, but they are manufactured by different companies using different purification processes and different unit assay systems. A "unit" of Botox and a "unit" of Dysport are measured by different bioassay methods — so they do not represent the same biological activity. This is why direct unit-to-unit comparisons require a conversion factor.
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Neither is inherently "stronger" — they are different formulations that require different doses to achieve equivalent effects. Dysport units are smaller, so more units are needed. Think of it like comparing milligrams and micrograms — you need more micrograms to equal one milligram, but the total effect can be identical. Dysport is sometimes described as spreading slightly more than Botox, which can be an advantage in large muscle areas but requires precision in areas near the eyes.
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No. Botulinum toxin is a prescription medication that must be administered by a qualified medical professional. These conversion ratios are educational references. The actual dose used for any individual depends on clinical assessment, muscle anatomy, desired outcome, and professional judgment. Never self-adjust doses or attempt to convert between products without consulting your treating practitioner.
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The 1:2.5 ratio is commonly used as a general starting point, but some evidence suggests the optimal ratio may vary slightly by treatment area. For glabellar lines (the 11s between the eyebrows), clinical trials suggest ratios between 1:2.5 and 1:4. For larger muscle groups like masseters (jaw), some practitioners use 1:3. The ratio is a guide — experienced practitioners titrate dose to individual response.
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Both products provide effects lasting roughly 3–4 months for most patients, though individual variation is significant. Some patients notice Dysport results appearing slightly faster (within 2–3 days vs 3–5 for Botox), though both reach full effect at 2 weeks. The clinical difference in duration between the two products at equivalent doses is minimal when properly dosed.
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Several FDA-approved botulinum toxin type A products are available: Botox/Botox Cosmetic (Allergan/AbbVie), Dysport (Ipsen/Galderma), Xeomin (Merz), Jeuveau (Evolus), and Daxxify (Revance). Each has its own unit system. Xeomin units are generally considered equivalent to Botox units (1:1), while Jeuveau is also approximately 1:1 with Botox. Daxxify has a different profile and duration. Never assume one product's units equal another's without verifying with your provider.
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Typical Botox doses vary by area: forehead lines: 10–30 units; glabellar (11 lines): 20–30 units; crow's feet (per side): 10–15 units; brow lift: 2–5 units per side; lip flip: 4–8 units; neck bands (platysma): 25–50 units; hyperhidrosis (underarms): 50–100 units per side. These are general ranges — individual dosing by a qualified injector may differ significantly.