Botox vs. Dysport: What's the Actual Difference?

Patients ask me this almost every week: is Dysport just a cheaper Botox, or is one of them actually better? Neuromodulator injections are the most common minimally invasive cosmetic procedure in the United States, with nearly 9.9 million counted by the American Society of Plastic Surgeons in 2024. We offer both at Reset You MD, so here is what they share, where they differ, and how we choose.

What Botox and Dysport have in common

Both are botulinum toxin type A, a purified protein made by the bacterium Clostridium botulinum. Injected in tiny amounts into a specific muscle, it blocks the release of acetylcholine, the chemical signal that tells that muscle to contract. The muscle relaxes and the line softens. The nerve endings slowly recover over the following months, which is why the effect wears off.

Both are FDA-approved prescription medicines: Botox Cosmetic (onabotulinumtoxinA) and Dysport (abobotulinumtoxinA). The two labels agree on the basics of safe use. Do not inject an area with an active infection. Do not use either product in anyone who has had an allergic reaction to a botulinum toxin product. And do not treat more often than every three months: the Dysport label says so directly, and the Botox label notes that more frequent dosing has not been studied.

Both also carry an FDA boxed warning. The effects of any botulinum toxin product "may spread from the area of injection" and, rarely, cause trouble swallowing or breathing hours to weeks later. The Botox label adds that no definitive serious reports of that kind have been linked to its use at the labeled doses for the frown, crow's-feet, and forehead areas. The warning still applies to every product at every dose, and it is why these injections belong in a medical setting with a careful history.

Difference one: the units are not the same

This causes most of the confusion. A "unit" is a measure of biological potency, and each manufacturer defines it with its own test. The Botox label states that its units "cannot be compared to nor converted into Units of any other botulinum toxin products." The Dysport label says its units "are not interchangeable with other preparations of botulinum toxin products."

In practice, it takes more Dysport units than Botox units to treat the same area. The FDA-labeled dose for frown lines is 20 units of Botox Cosmetic or 50 units of Dysport, a ratio of 2.5 to 1. Published comparisons have mostly used ratios of 2.5 to 1 or 3 to 1. Part of the disagreement about which product spreads farther or lasts longer comes down to the dose ratio, dilution, and injection technique a study used.

Difference two: which areas each is approved for

Botox Cosmetic is FDA-approved for four areas in adults: frown lines between the brows, crow's feet, forehead lines, and, as of October 2024, the vertical neck bands made by the platysma muscle. Dysport's cosmetic approval is for frown lines in adults under 65. Its placebo-controlled trials included only eight people 65 and older, and the label notes that efficacy was not observed in that small group.

Physicians can and do use both products in other areas: crow's feet or forehead lines with Dysport, or bunny lines, a lip flip, and chin dimpling with either. That is called off-label use. The FDA itself notes that once a drug is approved, providers "generally may prescribe the drug for an unapproved use when they judge that it is medically appropriate," but it also means the agency has not determined that the drug is safe and effective for that use. We tell you when a recommended treatment is off-label so you can decide with the full picture.

Difference three: onset, duration, and spread

Onset

Both products begin working within days. The Botox Cosmetic label describes an effect starting one to two days after injection and "increasing in intensity during the first week." A 2020 systematic review of 42 Dysport studies found onset most often reported at two to three days, and as early as 24 hours in two studies. Many injectors have the impression that Dysport shows up a little sooner. Some head-to-head studies in that review found Dysport a day or so faster; others found no difference. Either way, judge the result at two weeks, not two days.

Duration

The Botox label puts the duration of effect for frown lines at approximately three to four months. The Dysport label says its effect "may last up to four months." In the Botox frown-line trials, 25% of patients still met the investigator's definition of response at day 120, and 39% still rated themselves at least moderately improved.

Does one last longer? A 2011 split-face study treated one side of the forehead with Dysport and the other with Botox, at a 2.5-to-1 ratio, in 20 women. The Dysport side kept its effect longer on all six measures, by about one to six weeks depending on the yardstick, though one difference was not statistically significant. The study was small and funded by Medicis, which then marketed Dysport in the United States. The 2020 review, sponsored by Ipsen, which makes Dysport, found several comparisons favoring Dysport, a few favoring Botox, and many showing no significant difference. My reading: both typically last three to four months, and Dysport may run a few weeks longer in some people. Individual results vary more than the products do.

Spread

Botulinum toxin diffuses a short distance from where it is placed. A 2025 split-face study measured that spread on the forehead as the patch of skin that stopped sweating. At a 1-to-2.5 ratio, the patch was largest with Dysport, next largest with Botox, and smallest with a newer product whose maker funded the study. Each was compared with the newer product rather than directly with the other, and wrinkle improvement was similar for all three. A wider field of effect can help across a broad forehead and is less welcome near the brow or eyelid, where precision matters. Dilution and technique change spread as well.

What the best head-to-head evidence says

The most rigorous summary comes from a 2021 Cochrane review of 65 randomized trials with 14,919 participants. Against placebo, each of the four toxins the review could assess clearly reduced frown lines at four weeks. In the one direct comparison at labeled doses, 50 units of Dysport and 20 units of Botox were equally likely to succeed. The relative risk was 1.00 by the patient's rating and 1.01 by the physician's, and the reviewers rated that evidence high-certainty.

The same review found that botulinum toxin "probably increases risk of ptosis," a temporary drooping of the eyelid or brow. In the labels, eyelid drooping occurred in 3% of Botox frown-line patients and 2% of Dysport patients, versus 0% to under 1% with placebo. Its one direct comparison found major side effects, mainly drooping, were probably more likely with 50 units of Dysport than 20 units of Botox, but the estimate was imprecise and included no difference. Headache was reported by 9% of patients in both the Dysport frown-line trials and the Botox forehead-line trials, against about 5% with placebo. Bruising, swelling, and tenderness at the injection sites happen with both and are usually short-lived.

One difference lives in the fine print. Dysport "may contain trace amounts of cow's milk protein" and is contraindicated in people allergic to it. Both products contain human albumin. Both labels advise caution in people with neuromuscular conditions such as myasthenia gravis, Lambert-Eaton syndrome, or ALS, and in anyone taking aminoglycoside antibiotics or other drugs that affect nerve-to-muscle signaling. Neither has adequate studies in pregnancy, so we postpone treatment during pregnancy and breastfeeding.

How we choose at Reset You MD

Both products work, and in most faces either can give a good result. Here is what tips the decision:

• The area. For a broad forehead or a strong frown complex, Dysport's slightly wider spread can be an advantage. For small, precise targets such as a lip flip, bunny lines, or lines close to the brow, we usually prefer Botox.
• Your history. If one product has given you a result you liked, for as long as you hoped, we stay with it.
• Allergies and health conditions. A cow's-milk allergy rules out Dysport. Neuromuscular disease, certain antibiotics, and pregnancy change the plan for both.
• The kind of line. Neuromodulators soften lines made by movement. A crease that is etched in even when your face is at rest may call for filler, Sculptra, or microneedling instead of more toxin.
• Timing. Before an event, we schedule either product about two weeks ahead so the result has settled and any bruise has faded.
• Your budget. We give you a unit estimate and a total before we treat, so the comparison is apples to apples.

Whichever product we choose, the approach is the same: a conservative dose that softens movement rather than freezing it, placed by someone who knows the anatomy, and judged at two weeks when the effect is fully in. If you have been wondering whether Botox or Dysport is right for you, book a complimentary consultation. We will go over your goals, your history, and your lines, and tell you plainly which product fits and why.

Website content is for general education and does not replace individualized medical advice, diagnosis, or treatment. Individual results vary. This article is general education from a Florida physician and does not create a doctor–patient relationship; talk with your own clinician about your situation.