What is the difference between Botox (Botulinum toxin) and Dysport (AbobotulinumtoxinA) for treating wrinkles?

Dysport vs Botox for Wrinkle Treatment

Both Dysport (abobotulinumtoxinA) and Botox (onabotulinumtoxinA) are highly effective FDA-approved treatments for facial wrinkles with comparable efficacy, though they differ in dosing units, diffusion characteristics, and require specific expertise for optimal results.

Key Differences Between Products

Dosing and Unit Conversion

• Units are NOT interchangeable between Dysport and Botox—this is a critical safety consideration 1
• Dysport typically requires higher unit doses compared to Botox due to different potency measurements and manufacturing processes 1, 2
• Both products are derived from Clostridium botulinum type A through proprietary manufacturing processes, making them distinct pharmaceutical products 1

Diffusion and Spread Characteristics

• Dysport (type B formulations) may demonstrate different diffusion profiles that could be advantageous for treating larger areas like crow's feet 2
• Spread depends on solution volume and injection technique, while diffusion is largely dependent on toxin dose and receptor concentration 1
• The toxin moves down a concentration gradient from areas of high to low receptor concentration 1

Comparative Efficacy for Glabellar Lines

Dysport (AbobotulinumtoxinA-50 U)

• Achieves high participant-assessed success rates compared to placebo (RR 21.22,95% CI 7.40 to 60.56) at 4 weeks 3
• Demonstrates high physician-assessed success rates (RR 14.93,95% CI 8.09 to 27.55) 3
• May result in slightly more adverse events compared to placebo (RR 1.25,95% CI 1.05 to 1.49) 3

Botox (OnabotulinumtoxinA-20 U)

• Shows comparable participant-assessed success rates to placebo (RR 19.45,95% CI 8.60 to 43.99) at 4 weeks 3
• Achieves strong physician-assessed success rates (RR 17.10,95% CI 10.07 to 29.05) 3
• Associated with increased major adverse events (Peto OR 3.62,95% CI 1.50 to 8.74) 3

Head-to-Head Comparison

• When directly compared, Dysport-50 U and Botox-20 U show no significant difference in participant-assessed success (RR 1.00,95% CI 0.92 to 1.08) or physician-assessed success (RR 1.01,95% CI 0.95 to 1.06) 3
• Dysport may have slightly higher rates of major adverse events (Peto OR 2.65,95% CI 0.77 to 9.09), though overall adverse event rates are similar (RR 1.02,95% CI 0.67 to 1.54) 3

Clinical Application Guidelines

Treatment Expectations

• Effects develop over approximately 2 weeks and last 3-4 months for both products 4
• Dynamic wrinkles (visible during muscle contraction) respond more dramatically than static wrinkles (visible at rest) 4
• Treatment satisfaction is high, with women achieving better results than men (80% vs 43%, P ≤ 0.03) 5

Dosing Strategy for Glabellar Lines

• Begin with 10.0 mouse units per corrugator muscle for Botox, with potential for re-injection if persistent muscle activity remains 5
• For Dysport, use appropriate conversion ratios recognizing units are not equivalent 1
• Dose adjustments should be based on EMG-guided assessment of muscle activity when available 5

Patient Selection Criteria

• Ideal candidates have dynamic wrinkles that spread with muscle contraction (positive "glabellar spread test") 5
• Improvement is dose-dependent but not age-related 5
• Some patients may not achieve satisfactory results even with successful muscle denervation 5

Safety Profile and Adverse Events

Common Adverse Events

• Minor bruising is the most common side effect for both products 4
• Major adverse events include eyelid ptosis (drooping), which is primarily technique-dependent and decreases with injector experience 3, 4
• Risk of strabismus and eyelid sensory disorders exists with both formulations 3

Contraindications

• Absolute contraindications include: keloidal scarring, neuromuscular disorders (myasthenia gravis), allergies to product constituents, and body dysmorphic disorder 4
• Both products should be avoided in patients with these conditions 4

Clinical Pitfalls to Avoid

• Never assume unit equivalence between products—this is the most critical error leading to over- or under-dosing 1
• Avoid treating static wrinkles as primary targets, as results will be less dramatic than with dynamic wrinkles 4
• Recognize that injection technique significantly impacts spread and diffusion, requiring specific training for each product 1
• Beyond glabellar lines, evidence for Dysport is limited to few randomized controlled trials, whereas more data exists for other indications 1

Evidence Quality Note

The evidence comparing these products for wrinkle treatment is high to moderate quality for efficacy outcomes, with direct head-to-head comparisons showing essential equivalence when properly dosed 3. However, clinicians must develop familiarity with their chosen product's specific dosing and handling characteristics to achieve consistent, safe results 1.