How Long Does Dysport Last? Onset, the Label Timeline, and Why 2–3 Days Is Not in the PI

For its sole FDA-approved aesthetic indication—temporary improvement in the appearance of moderate to severe glabellar lines (vertical frown lines between the eyebrows) in adults under 65 years of age—Dysport (abobotulinumtoxinA, BLA 125274, Galderma / Ipsen) carries an explicit regulatory timeline in its United States Prescribing Information (US PI):

1. Labeled Duration: "The clinical effect may last up to 4 months." (Section 2.4, Dosing in Glabellar Lines).
2. Retreatment Frequency: "DYSPORT should be administered no more frequently than every 3 months."
3. Approved Glabellar Dose: Exactly 50 Units total, divided into five equal intramuscular injections of 10 Units (0.05 mL) each.

However, widespread marketing shorthand across clinic websites—claiming that "Dysport kicks in within 24 to 48 hours and lasts noticeably longer than Botox"—obscures what the underlying pivotal trial datasets actually proved:

• "Up to four months" is a statistical tail, not the median patient experience. In pivotal trial GL-1, investigator-rated "none or mild" glabellar severity peaked at Day 14 (90%) and Day 30 (88%), declined to 43% at Day 90 (month 3), and reached 23% at Day 120 (month 4).
• The 2-to-3-day onset claim is clinical lore, not a labeled FDA claim. The official package insert does not publish a median-onset time (in contrast to Xeomin, which explicitly claims median onset within seven days in its PI). GL-1's first tabulated post-baseline efficacy visit was Day 14.
• Dysport does not last longer than Botox on official US labels. Both BOTOX Cosmetic and Dysport are labeled with a duration of up to 3 to 4 months. Daxxify remains the only FDA-approved neuromodulator labeled with a median 6-month duration.
• Dysport units are not interchangeable with Botox units. 50 Dysport Units is the standard glabellar dose, not 20 Units.

This comprehensive guide analyzes the 180-day trial datasets behind BLA 125274, explains the molecular biology of neuromuscular recovery, details why retreatment every three months is the labeled minimum, and provides a clinical troubleshooting framework for patients experiencing early wear-off.

---

Direct Comparison: Neuromodulator Longevity, Onset, and Labeled Dosing

---

The GL-1 Pivotal Trial Timeline: 180 Days of Data Analyzed

To understand how Dysport wears off over time, one must examine Table 17 from Section 14 (Clinical Studies) of the FDA Prescribing Information (DailyMed SPL setid 71313a04-1349-4c26-b840-a39e4a3ddaed, effective 24 October 2024).

In pivotal study GL-1, 158 adult subjects with moderate to severe glabellar lines were randomized (105 received Dysport 50 Units; 53 received placebo) and evaluated at post-injection visits through Day 180 (6 months). The table below is investigator-rated “none or mild” at maximum frown from PI Table 17 — not a patient-satisfaction curve.

Table: Investigator-rated glabellar severity “none or mild” at maximum frown (Study GL-1)

Composite 2-grade responder success at Day 30 across GL-1, GL-2, and GL-3

The primary efficacy endpoint used for approval was a composite ≥2-grade improvement from baseline at Day 30, assessed independently by both the blinded investigator and the patient (PI Table 16):

• Study GL-1: 55% (58/105) Dysport vs. 0% (0/53) placebo.
• Study GL-2: 52% (37/71) Dysport vs. 0% (0/71) placebo.
• Study GL-3: 60% (120/200) Dysport vs. 0% (0/100) placebo.

GL-1 and GL-3 were single-dose, placebo-controlled studies. GL-2 was a repeat-dose study: two or three open-label 50-Unit cycles, then randomization of 142 subjects into a final blinded cycle (71 Dysport, 71 placebo). It is not a free-standing open-label extension of GL-1, and GL-3 is not an extension of either.

Key takeaways from the 180-day GL-1 investigator table

1. The tabulated peak is at 2 to 4 weeks: none/mild is 90% at Day 14 and 88% at Day 30.
2. Month 3 is the inflection: between Day 60 and Day 90, investigator none/mild falls from 64% to 43%. A patient who says the effect “only lasted 2.5 months” is describing a curve the label already shows, not a product failure by itself.
3. Month 4 is the tail, not the typical patient: 23% still none/mild at Day 120 is why the PI can say the clinical effect may last up to four months. That is not the median experience.

---

Molecular Biology: How Neuromuscular Blockade Wears Off

To understand why neuromodulator effects decline over 90 to 120 days, it is necessary to examine the biological mechanism of botulinum toxin type A at the presynaptic motor nerve terminal:

1. Binding and internalization. The heavy chain binds presynaptic receptors; the light chain enters the neuron.
2. SNAP-25 cleavage. The light chain, a zinc endopeptidase, cleaves SNAP-25 and blocks acetylcholine-vesicle fusion.
3. Blockade (roughly the first month). Acetylcholine release at treated endplates is reduced; the muscle is chemically weakened.
4. Sprouting. Temporary axonal side-branches can form and restore some contraction under effort.
5. Parental-terminal recovery. The original endplate reconstitutes intact SNAP-25; sprouts regress; baseline transmission returns.

These steps explain a population fade curve. They are not a stopwatch for any one patient.

1. SNAP-25 Cleavage

AbobotulinumtoxinA consists of a 100 kDa heavy chain and a 50 kDa light chain linked by a disulfide bridge. The light chain is a zinc-dependent endopeptidase that cleaves SNAP-25 (synaptosomal-associated protein 25 kDa), a crucial member of the SNARE protein complex. Without intact SNAP-25, acetylcholine vesicles cannot fuse with the presynaptic cell membrane to release neurotransmitters into the synaptic cleft.

2. The Sprouting Phase (Weeks 4 to 10)

Denervated nerve terminals do not remain passive. Starting around 28 to 35 days post-injection, the presynaptic axon generates fine collateral extensions known as axonal sprouts. These sprouts establish temporary, low-efficiency neuromuscular junctions with adjacent muscle fibers, allowing partial acetylcholine release. This is why patients begin noticing faint dynamic movement around week 8 to 10.

3. Restoration of the Primary Synapse (Weeks 10 to 16)

Over months 3 and 4, the intracellular concentration of active toxin light chain is degraded by host proteasomes. The original, mature motor endplate synthesizes new, uncleaved SNAP-25 proteins, restoring full vesicle fusion capacity. As the primary synapse recovers, the temporary collateral sprouts regress, returning the muscle to baseline contractile strength.

---

Reconstitution, Dilution, and In-Vial Stability

The physical handling, dilution volume, and storage of Dysport directly influence clinical spread and delivered potency.

1. Official Prescribing Information Dosing & Dilution Guidelines (Section 2.2)

Dysport is supplied as a lyophilized powder in single-dose vials of 300 Units or 500 Units.

• Reconstitution vehicle: Must be reconstituted with sterile, preservative-free 0.9% Sodium Chloride Injection, USP.
• Labeled glabellar concentrations (PI Table 2): For glabellar lines in adults, the recommended concentrations are 20 Units/0.1 mL or 12 Units/0.1 mL — on a 300-Unit vial that is 1.5 mL or 2.5 mL of saline. The 50-Unit glabellar dose is then five aliquots of 10 Units (0.05 mL at 20 U/0.1 mL, or 0.08 mL at 12 U/0.1 mL).
• Not a glabellar recommendation: Table 1 also lists a 300-Unit vial plus 3 mL (10 Units/0.1 mL). Table 2 assigns that 10 Units/0.1 mL concentration to adult spasticity, not glabellar lines. Do not treat 3 mL as the labeled frown-line dilution.

2. Reconstitution Technique

Inject the diluent gently down the inside wall of the vial. The package insert instructs providers to swirl gently to dissolve. Do not use the vial if no partial vacuum is observed.

3. Temperature Storage and Expiration

• Unopened vials: Refrigerate at 2°C to 8°C (36°F to 46°F) in the original carton, protected from light.
• Reconstituted solution: Section 2.2 specifies refrigerated storage (2°C to 8°C) and use within 24 hours. The PI does not authorize using a reconstituted vial days or weeks later.

---

Does Dysport Work in 2 to 3 Days? Clinical Lore vs. FDA Reality

A pervasive marketing assertion across med spas is that Dysport "kicks in in 24 to 48 hours, whereas Botox takes a week."

What the FDA Label Actually Says

The US Prescribing Information for Dysport contains no labeled claim regarding 2-to-3-day onset.

• Unlike Xeomin, which states that median onset of effect was observed within seven days, the Dysport package insert does not tabulate onset before Day 14. Daxxify’s US PI, checked 25 August 2026, likewise does not carry a Xeomin-style median-onset sentence; 1–2 day notice is diary/marketing language, not a Dysport-vs-Daxxify labeled race.
• In the glabellar registration tables, the first investigator none/mild snapshot is Day 14.

Why do injectors and patients report faster onset?

Despite the lack of an explicit PI claim, many patients and injectors report early softening by Day 2 to Day 4. That can be true in practice without being a labeled differentiator. Excipients (human serum albumin 125 mcg and lactose 2.5 mg per vial) are in the PI; they do not prove a 48-hour onset. Diffusion differences versus onabotulinumtoxinA are often discussed in clinic and in conversion literature; they are not a Dysport PI onset claim.

Even if early relaxation is felt at 48 hours, wait until Day 14 before judging symmetry or asking for a touch-up. The first tabulated GL-1 investigator snapshot is Day 14.

---

Does Dysport Last Longer Than Botox?

Patients frequently ask whether switching from Botox to Dysport will extend their treatment intervals from 3 months to 5 months.

The evidence-based answer is no — not on the US labels.

1. Label claims occupy the same 3-to-4-month window for BOTOX Cosmetic and Dysport. Neither PI says Dysport lasts longer.
2. Head-to-head duration is mixed and unit-conversion confounded. Aesthetic conversion studies are not a substitute for the labeled 50-Unit vs 20-Unit glabellar doses. See Botox vs Dysport for the conversion debate rather than a secret longer-lasting formula.
3. The duration outlier is Daxxify, with a labeled median of about 24 weeks. Compare also how long Botox lasts and how long Xeomin lasts.

For a complete breakdown of product characteristics, spread, and pricing, see our head-to-head analysis of Botox vs Dysport.

---

Unit Dosing & Conversion: Why 50 Units Is Not 20 Units

A common source of patient anxiety is the numerical unit count. Patients accustomed to receiving "20 units of Botox" are often startled when an injector recommends "50 or 60 units of Dysport," wondering: "Is 20 units of Dysport a lot?"

Units are not interchangeable — that is not the boxed warning

The Dysport boxed warning is distant spread of toxin effect (swallowing and breathing difficulty), the same class warning as other botulinum toxins. Unit non-interchangeability is a separate Dosage (2.1) and Warnings (5.2) statement:

The potency units of DYSPORT are not interchangeable with other preparations of botulinum toxin products and, therefore, units of biological activity of DYSPORT cannot be compared to or converted into units of any other botulinum toxin products assessed with any other specific assay method.

• BOTOX Cosmetic labeled glabellar dose: 20 Units total (4 Units per injection site).
• Dysport labeled glabellar dose: 50 Units total (10 Units per injection site).

Answering “Is 20 Units of Dysport a lot?”

No. 20 Units of Dysport is not the labeled glabellar dose.

The PI forbids converting units across products. Clinic planning often uses an approximate 2.5:1 to 3:1 Dysport:Botox discussion ratio so that 50 Dysport Units maps onto the same five-point frown pattern as 20 onabotulinumtoxinA Units — that is practice arithmetic, not an FDA conversion factor. Twenty Dysport Units in the glabella is simply not the labeled 50-Unit regimen. For session-price math, see Dysport cost per unit.

---

Off-label treatment areas: why duration anecdotes are not PI data

The US aesthetic indication is glabellar lines in adults younger than 65. Forehead lines, crow’s feet, masseter, lip flip, and platysma are off-label for Dysport. There is no labeled unit count for those sites, and this page will not publish a universal off-label dose table.

What the label can still teach:

---

Retreatment Intervals: Is Getting Dysport Every 3 Months Safe?

Patients frequently worry whether receiving injections every 90 days will cause tissue damage, muscle wasting, or toxic buildup.

Retreatment no sooner than every 3 months is the labeled interval, not a safety slogan.

• Section 2.4: Dysport should be administered no more frequently than every 3 months. Repeat dosing in clinical studies demonstrated continued efficacy with up to four repeated administrations.
• What GL-2 and GL-3 actually were: GL-3 was a single-dose placebo-controlled study. GL-2 was a repeat-dose study with two or three open-label cycles then a randomized final cycle — not “GL-2 and GL-3 were open-label extensions.” The “up to four administrations” language lives in section 2.4, not as a proof that more frequent than every 12 weeks is safe.

Why injecting sooner than 12 weeks is discouraged

The PI’s interval is a labeled floor. Shorter booster cycles are a reason to discuss immunogenicity with the injector — not a DIY schedule. In the glabellar immunogenicity dataset in the PI, none of 1,554 subjects with up to nine treatment cycles tested positive for neutralizing antibodies (a small number had binding antibodies). That is not “zero risk forever,” and it is not a license to retreat at week 6. For secondary nonresponse, see when Botox stops working.

---

Clinical troubleshooting: what to ask when it “wore off early”

Do not treat the following as a home dosing protocol. It is a question list so a Day-14 failure is not confused with a Day-90 fade.

1. At Day 14, was movement ever fully reduced? If significant frown remains at two weeks, the question is placement, depth, or whether the labeled 50-Unit glabellar dose was used — not “Dysport doesn’t last.” Touch-up timing and extra units are the injector’s call, not a universal add-on of 10–20 Units.
2. Did it work at Day 14 and fade by week 6–8? Ask whether the treated area was on-label glabella vs an off-label high-mobility zone; whether the vial used a Table 2 glabellar concentration (1.5 mL or 2.5 mL per 300-Unit vial) rather than a spasticity dilution; and whether a longer-duration product such as Daxxify is even the right conversation. Do not self-increase from 50 to 60 Units.
3. Is this simply Day 90? In GL-1, investigator none/mild was 43% at Day 90 (57% no longer met that bar). That is the labeled retreatment neighborhood, not treatment failure.

Why duration varies (without a DIY dose ladder)

If the effect seems gone at 6–8 weeks, the useful differentials are: less than the labeled 50 Units in the glabella; off-label area with conservative placement; high-mobility muscles; technique/depth; and, rarely, neutralizing antibodies. The PI’s glabellar immunogenicity sample found 0 neutralizing positives among 1,554 subjects; binding antibodies were uncommon. That is not a <1% incidence statistic for all aesthetic use.

Athletes sometimes report shorter windows; that is clinical observation, not a labeled “exercise clears toxin” claim. Exercise does not sweat the drug out.

---

Questions to Ask Your Provider About Dysport Duration

To ensure you achieve optimal longevity from your treatment, bring these questions to your consultation:

1. "Are you administering the full FDA-labeled dose of 50 Dysport Units for my frown lines, or are you modifying the dose based on my muscle strength?"
   Why to ask: Prevents under-dosing, the primary cause of premature wear-off.
2. "What is your reconstituted concentration (e.g., 1.5 mL or 2.5 mL per 300-Unit vial), and how many units will be placed in each injection point?"
   Why to ask: Ensures precision in volume and unit delivery.
3. "Do you recommend waiting the full 14 days before assessing symmetry or considering touch-ups?"
   Why to ask: Confirms the injector respects the biological timeline of synaptic blockade.
4. "If I want my treatment to last 4 months, what maintenance interval do you recommend?"
   Why to ask: Establishes a safe 3-to-4-month schedule that prevents immunogenicity while maintaining muscle relaxation.

---

Frequently Asked Questions

How long does Dysport last?

On the FDA label, Dysport's clinical effect may last up to 4 months. In clinical trials (GL-1), 88% of patients had none or mild frown lines at 1 month, 43% maintained this at 3 months, and 23% maintained it at 4 months. Most patients schedule retreatments every 3 to 4 months.

How long does Dysport take to work?

Many patients report initial relaxation within 2 to 4 days, but full clinical results take 10 to 14 days. The FDA prescribing information tabulates efficacy starting at Day 14.

Does Dysport last longer than Botox?

No. On FDA-approved labels, both Dysport and BOTOX Cosmetic describe glabellar duration in the 3-to-4-month range. Conversion-confounded clinic comparisons are not a reason to choose Dysport for extra longevity.

Does Dysport work faster than Botox?

Some patients and injectors report earlier initial softening (often 2–3 days vs 3–5 days), but that is not an FDA-labeled comparative claim. Judge the result at 14 days.

Is it bad to get Dysport every 3 months?

No. Every 3 months is the labeled minimum retreatment interval. More frequent cycles are outside that labeled floor and are a conversation about immunogenicity, not a DIY booster plan.

Is 20 units of Dysport a lot?

No. The labeled frown-line dose is 50 Units. Twenty Dysport Units is not that dose. The PI says units cannot be converted to Botox Units.

Why does my Dysport wear off so fast?

Ask whether the Day-14 result was ever complete, whether the area was on-label glabella at 50 Units, and whether you are describing the GL-1 fade (43% still none/mild at Day 90) rather than a failed product.

---

Sources

• U.S. Food and Drug Administration / DailyMed: DYSPORT (abobotulinumtoxinA) Prescribing Information, BLA 125274, Set ID 71313a04-1349-4c26-b840-a39e4a3ddaed (Effective 24 October 2024): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=71313a04-1349-4c26-b840-a39e4a3ddaed
• U.S. Food and Drug Administration, Drugs@FDA Database: Biologics License Application BLA 125274 (Dysport): https://www.accessdata.fda.gov/scripts/cder/daf/
• U.S. Food and Drug Administration / DailyMed: BOTOX Cosmetic (onabotulinumtoxinA) Prescribing Information, BLA 103000: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=485d9b71-6881-42c5-a620-a4360c7192ab
• Galderma Aesthetics, US Healthcare Professional Portal: Dysport Prescribing Information & Dosing Guidelines: https://www.dysportusa.com/
• American Society for Dermatologic Surgery (ASDS): Neuromodulator Treatment Guidelines and Patient Information: https://www.asds.net/skin-experts/skin-treatments
• American Academy of Dermatology (AAD): Botulinum Toxin Therapy Overview: https://www.aad.org/public/cosmetic/wrinkles/botulinum-toxin-overview
• U.S. Food and Drug Administration / DailyMed: XEOMIN (incobotulinumtoxinA) Prescribing Information, BLA 125360, Set ID 3f35d6e0-3450-4abc-a0da-cc7b277e7c6e (onset contrast: median onset within seven days): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3f35d6e0-3450-4abc-a0da-cc7b277e7c6e