Dysport is a botulinum toxin and Juvederm is a family of hyaluronic acid fillers, so they are not alternatives to each other. Dysport relaxes a muscle. Juvederm adds physical volume under the skin. If you have been offered both in one appointment, you are being treated for two different problems, not sold the same thing twice.
Dysport's US cosmetic approval is narrow. Its FDA label covers "the temporary improvement in the appearance of moderate to severe glabellar lines associated with procerus and corrugator muscle activity in adults < 65 years of age" - the frown lines between the brows, and nothing else on the cosmetic side. Note the age wording, which is unusual. The label dose is 50 Units total, given as five equal 10-Unit injections. Those are Dysport Units, and they do not travel: the label states that Dysport's potency units "cannot be compared to or converted into units of any other botulinum toxin products."
"Juvederm" is not one product either. It is a family of separately FDA-approved gels, each with its own approval date, its own approved area and its own trial. Voluma XC covers cheeks, chin and temples. Ultra XC covers facial wrinkles and folds, and lips. Volbella XC covers lips, perioral lines and under-eye hollows. Vollure XC covers facial wrinkles and folds. Volux XC covers jawline definition. Skinvive covers skin smoothness of the cheeks, and since June 2026, neck lines. A duration number from one of them tells you nothing about another.
No trial has ever compared Dysport against a Juvederm product, and a useful one could not be designed. There is no shared outcome to measure. The frown line Dysport is approved for is a muscle problem; the cheek, lip or under-eye area a Juvederm product is approved for is a volume problem.
Its own FDA label describes it as "an acetylcholine release inhibitor and a neuromuscular blocking agent." It blocks the chemical signal that tells a muscle to contract, so the muscle relaxes. Nothing is added to the face.
Class III devices approved through the FDA's premarket approval route, which required clinical evidence for one named area at a time.
That is the whole US cosmetic indication. Dysport holds no FDA cosmetic indication for crow's feet or forehead lines.
Voluma XC: cheeks (2013), chin (2020), temples (2023, with an FDA-required training programme for injectors). Ultra XC: facial wrinkles and folds, plus lips (2015). Volbella XC: lips and perioral lines (2016), under-eye hollows (2021). Volux XC: jawline definition (2022).
Hollow cheeks, a flat chin, thin lips, a fold that stays visible when your face is still.
Never convert this to another brand's units. Every toxin label says so in its own words.
Syringes are commonly 0.5 mL or 1.0 mL depending on the product; a 0.55 mL fill of Juvederm Ultra, Ultra XC and Ultra Plus XC was approved in 2019.
The effect fades as nerve terminals regrow and the protein the toxin destroyed is replaced.
Juvederm Voluma XC in the cheeks: 85.6% of treated subjects met a one-grade improvement at 6 months, 85.2% at 12 months and 67.1% at 24 months. Juvederm Vollure XC in nasolabial folds: 93.2% at 6 months, then 57.5% at 12 months and 59.4% at 18 months.
In the US that use is off-label: the FDA labeling for Hylenex lists three indications, and dissolving dermal filler is not one of them. In laboratory testing, Juvederm gels were among the most resistant tested, needing 300 units of enzyme to degrade within an hour - that was in a dish, not in tissue.
Headache and eyelid ptosis - a drooping upper eyelid - appear as treatment-related events in toxin trials.
In the Juvederm Volbella XC under-eye trial, tenderness was reported by 49.5%, bruising by 42.7% and swelling by 41.7%, mostly mild and settling within a week. The serious risk is filler entering an artery.
Because they do not compete. Most faces have both a dynamic problem and a volume problem, and a line that is etched in now usually started as a line that only appeared on movement.
There is a small randomized literature on adding filler to toxin, and it is worth reading for what it does and does not show. A three-arm randomized trial in the lower face put 90 women in three groups: onabotulinumtoxinA alone, a 24 mg/mL cohesive hyaluronic acid gel alone, or both. The authors reported that for all endpoints and most timepoints, the group treated with both had greater improvement from baseline than either treatment alone. The products were Allergan's, so treat it as industry-associated. A 20-person split-face trial of toxin alone against toxin plus HA filler on the forehead and glabella found comparable results at 2, 6 and 12 weeks, with the combination side showing a longer-lasting effect by week 24; the authors' own conclusion was deliberately modest, that the combination "may provide a slightly better cumulative benefit." A third study, 40 people in the glabella, found the combination scored better on the Facial Wrinkle Scale at weeks 20 and 28.
Two limits. These trials tested addition, not substitution - none of them asked whether a filler could replace a toxin. And none of them used Dysport by name, so the results belong to the toxins those studies actually used.
Dysport's label dose of 50 Units for glabellar lines is not a bigger dose than Botox Cosmetic's 20 Units for the same area. The two brands measure potency with different assays, and the numbers are not on the same scale. One randomized double-blind study of onset and duration made this concrete by deliberately using 21 Units of incobotulinumtoxinA, 21 Units of onabotulinumtoxinA and 63 Units of abobotulinumtoxinA in 180 people - the unit numbers differ because the units differ.
Where toxin brands have actually been compared head to head at their recommended doses, the repeated finding is no clinically meaningful difference in the glabella. An independent split-face trial of onabotulinumtoxinA against abobotulinumtoxinA in 53 people, followed for 150 days with blinded graders, found no statistically significant differences; the authors stated it was conducted without commercial support. Where brands genuinely differ is in unit scale, onset and price - not in whether they work.
These signs can mean filler has entered a blood vessel. Time is measured in hours.
Sudden vision change, blurring or loss of vision in either eye
Pain that is severe or out of proportion to the procedure
Skin that turns white or pale soon after the injection, then goes dusky, grey, purple or blotchy
Any stroke-like symptom: weakness, drooping, slurred speech, confusion
Vision loss from filler is usually permanent. In a review of 511 published cases dating back to 1906, of the 318 that reported the visual outcome, 6.0% recovered completely and 68.2% did not recover at all. Hyaluronic acid was the material in 79.6% of the recent cases. Do not wait to see if it settles, and do not assume pain will warn you - pain was mild or absent in 47% of intravascular events in a survey of experienced injectors.
Swelling that is still growing after the first few days instead of settling
A lump that has not softened
Redness spreading outward from the injection site, or a fever
New tenderness, firmness or swelling appearing weeks or months later
Filler that looks like it has moved from where it was placed
An eyelid or brow that has dropped after the toxin