Dysport results typically last three to four months for cosmetic treatment of frown lines. The FDA label states the clinical effect “may last up to four months,” and most people schedule their next appointment somewhere in the three-to-four-month window. That said, your personal timeline can shift meaningfully depending on your activity level, the area treated, and how many units you receive.
What the Clinical Data Shows
For the most common cosmetic use, smoothing the vertical lines between the eyebrows (glabellar lines), Dysport’s FDA-approved labeling says treatment “reduced the severity of glabellar lines for up to four months.” The recommended minimum interval between treatments is every three months, which gives you a practical range: most people start noticing movement returning around month three, and by month four the effect has faded enough to warrant a new session.
Clinical studies on other conditions offer a useful window into how duration plays out across different muscles. In cervical dystonia trials, 73 to 82 percent of patients didn’t need retreatment before 16 weeks (four months). In pediatric spasticity studies, 74 percent held their results through 12 weeks, but only about 41 percent made it to 16 weeks. The takeaway: duration isn’t one fixed number. It depends heavily on the muscle being treated, the dose, and the individual.
When Results Start and When They Fade
Dysport tends to kick in faster than some people expect. Most patients notice lines beginning to soften within two to three days, which is slightly quicker than Botox for many people. Full results settle in at about 10 to 14 days, regardless of which neurotoxin you choose. That faster onset doesn’t mean the product wears off sooner or gives a better final result; it’s simply a difference in how quickly the initial effect appears.
The fadeout is gradual, not sudden. You won’t wake up one morning with all your lines back. Instead, you’ll slowly regain muscle movement over a few weeks. Many people schedule their next appointment when they first start noticing movement returning rather than waiting for the full effect to disappear. This approach keeps a more consistent look between sessions.
How Dosing Affects Duration
The relationship between the number of units injected and how long results last is one of the most debated topics among injectors. The general consensus leans toward this: underdosing tends to shorten duration, while using the right amount for a given muscle maximizes both the result and how long it holds. If a muscle needs 50 units to fully relax but only receives 30, you’ll likely see a weaker result that wears off faster.
However, piling on extra units beyond what the muscle actually needs doesn’t reliably extend the timeline. Think of it like filling a glass. Once the glass is full, pouring more water doesn’t make it “more full.” The goal is hitting the optimal dose for each specific muscle, not simply injecting more. Spreading additional units across a wider area also doesn’t add longevity to the originally targeted muscles.
It’s worth knowing that Dysport uses different unit measurements than Botox. The most commonly cited conversion ratio is roughly 2.5 to 3 Dysport units for every 1 unit of Botox, though some practitioners use a 1:4 ratio. So if you’re switching from Botox and your provider says you’ll need more units of Dysport, that’s expected and doesn’t mean you’re getting a larger dose.
Why Results Vary From Person to Person
Your metabolism plays a real role. A controlled clinical trial published in Toxins found that physical activity level has a meaningful impact on how long neurotoxin results last. People with low activity levels maintained their results throughout the study, while those with moderate and high activity levels showed muscle recovery as early as the second month. The more active groups also had weaker initial responses, with a higher prevalence of visible lines at every follow-up point compared to the low-activity group.
The researchers suggested that intense exercise may raise levels of a growth factor (IGF-1) that speeds up nerve recovery, essentially helping the body rebuild the nerve-muscle connection that the toxin temporarily blocks. This doesn’t mean you should stop exercising to preserve your results, but if you’re a serious athlete or very active person and find your results fading at eight or nine weeks, your fitness routine is a likely explanation.
Other factors that influence duration include:
- Muscle strength and size. Stronger, thicker muscles (like those in the jaw or forehead of someone who furrows aggressively) can overpower the toxin faster than smaller, thinner muscles.
- Area treated. Crow’s feet, which involve thinner muscles, sometimes fade a bit sooner than frown lines for some people, while forehead lines can vary widely depending on muscle size.
- Treatment history. Some people report that after several consistent sessions, the muscle weakens from repeated disuse and results seem to last slightly longer between appointments. Clinical studies confirmed continued efficacy with up to four repeated treatments, though the FDA data focused on safety rather than measuring progressive duration changes.
Typical Maintenance Schedule
For cosmetic use, most people settle into a routine of three to four treatments per year. The FDA recommends waiting at least three months between sessions for glabellar lines, and at least 12 weeks for other approved uses. Injecting more frequently than that raises the risk of developing antibodies to the toxin, which can make it less effective over time.
In practice, many providers suggest booking your next appointment when you first notice movement returning rather than sticking to a rigid calendar. Some people genuinely get four months, others find themselves closer to three. After two or three treatment cycles, you’ll have a good sense of your personal timeline. If you consistently lose your results before the 12-week mark, that’s worth discussing with your provider, as it may point to underdosing, a very high metabolism, or the need to adjust your treatment plan.