How Long Does Letybo Last? What the Evidence Actually Shows

Letybo typically provides several months of improvement, but there is no exact number of days that applies to every patient. In a Phase III clinical trial for moderate-to-severe glabellar lines, the average time until first retreatment was about 127 days, or approximately 4.2 months. The study also found that the treatment effect remained statistically significant compared with placebo through 16 weeks. Individual results can be shorter or longer depending on treatment response, muscle activity, treatment technique and other factors.

At a Glance: How Long Does Letybo Last?

Onset: Letybo began showing measurable improvement within days in clinical research, with a median onset of 3 days in one Phase III study.

Peak improvement: Improvement generally develops progressively rather than appearing all at once.

Duration: In the Phase III trial, the treatment effect remained statistically distinguishable from placebo through 16 weeks.

Average time to retreatment: 127.26 days, or approximately 4.2 months, in the double-blind phase of the study.

Is that a guarantee? No. Clinical-trial averages do not predict exactly how long Letybo will last for an individual patient.

Does Letybo last longer than Botox? Current evidence does not establish that Letybo universally lasts longer than Botox.

Can results last longer than four months? Yes. Some patients may experience meaningful improvement beyond four months, while others may notice return of movement sooner.

How long a wrinkle relaxer lasts is only one part of the decision. If you’re also comparing treatment areas, onset, FDA-approved indications, safety, cost, and overall differences between both products, explore our complete Botox vs. Letybo comparison before deciding which option may be right for you.

Letybo vs. Botox: How Long Do They Last?

The Letybo Phase III study reported an average time to first retreatment of 127.26 days. A pooled analysis of four onabotulinumtoxinA trials involving 621 treated patients found a median duration of 120 days at maximum contraction among Day-30 responders. The American Academy of Dermatology describes botulinum toxin results generally as lasting about 3–4 months, sometimes longer. These numbers should not be interpreted as a direct head-to-head proof that one product lasts longer than the other.

What Is Letybo?

Letybo is the brand name for letibotulinumtoxinA-wlbg, a botulinum toxin type A product.

The FDA approved Letybo in the United States in 2024 for the temporary improvement in the appearance of moderate-to-severe glabellar lines associated with corrugator and/or procerus muscle activity in adults. The FDA-approved dose is 20 Units, administered as 4 Units at each of five injection sites.

Because Letybo is a prescription medication, treatment should be performed by an appropriately qualified healthcare professional.

How Quickly Does Letybo Start Working?

This is different from asking how long Letybo lasts.

In the Phase III clinical study, some patients reported improvement very early:

• 24% reported at least a one-point improvement by Day 0
• 44.5% by Day 1
• 63.9% by Day 2
• 74.5% by Day 3

The median time to onset was 3 days.

That doesn’t mean everyone will see a noticeable cosmetic change within three days.

Patients can experience different rates of response.

The American Academy of Dermatology states that most patients receiving botulinum toxin therapy see results within approximately 3 to 7 days.

The important distinction

Onset is not the same thing as peak result.

A patient may begin noticing reduced movement after several days while the overall cosmetic result continues developing.

When Do Letybo Results Peak?

There isn’t one universally defined “peak day” for every patient.

Botulinum toxin works by reducing nerve signaling to targeted muscles. As the effect develops, the treated muscles become less active and dynamic wrinkles may become less noticeable.

The Letybo Phase III study evaluated patients at multiple time points and found substantial improvement at Week 4. The highest composite responder rates occurred around this period in the study.

For patients, the practical takeaway is:

Don’t judge your final result immediately after treatment.

The treatment needs time to develop.

How Long Does Letybo Last in Clinical Trials?

This is where the evidence becomes particularly useful.

In the Phase III clinical trial involving 355 people with moderate-to-severe glabellar lines, the researchers evaluated efficacy, onset, duration and retreatment.

The treatment effect remained statistically significant compared with placebo through Week 16.

The mean time until first retreatment was:

127.26 days

That’s approximately:

4.2 months

The standard deviation was 65.6 days, demonstrating considerable variation between participants.

This is important because saying simply “Letybo lasts four months” oversimplifies the research.

A better statement is:

Clinical-trial data show that Letybo can provide several months of improvement, with an average time to first retreatment of approximately 127 days in one Phase III study. Individual duration varies.

Does Letybo Really Last 4 Months?

Often, but four months should not be treated as a guarantee.

The Phase III study’s average time to retreatment was approximately 4.2 months.

However, an average is not a promise.

Some patients may notice return of muscle movement earlier.

Others may continue to see meaningful improvement for longer.

The study’s standard deviation of 65.6 days illustrates how much individual responses can vary.

Can Letybo Last 5 or 6 Months?

It can, but that should not be presented as the typical expected duration.

Some patients may experience meaningful effects beyond four months.

However, the strongest clinical-trial evidence should be described using the actual study results rather than using unusually long-lasting individual experiences as though they represent the average patient.

For that reason, Azani should avoid marketing statements such as:

“Letybo lasts six months.”

A more medically responsible statement is:

“Letybo can provide several months of improvement, although duration varies from patient to patient.”

That distinction matters.

Does Letybo Last Longer Than Botox?

The evidence does not establish that Letybo universally lasts longer.

This is one of the most common claims patients encounter online.

The Letybo Phase III study reported an average time to first retreatment of 127.26 days.

A meta-analysis of four onabotulinumtoxinA clinical trials found a median duration of 120 days at maximum contraction among Day-30 responders, with 131 days at repose.

Those numbers are relatively close.

But this is not a head-to-head comparison of duration between the two products.

The studies differ in:

• Study design
• Patient populations
• Outcome measurements
• Definitions of treatment response
• Follow-up schedules
• Retreatment criteria

Therefore, it would be inappropriate to conclude from these numbers alone that Letybo lasts longer than Botox.

Why Do Some People Say Letybo Lasts Longer Than Botox?

There are several possible reasons patients may perceive a difference.

Individual biology

People metabolize and respond to medications differently.

Muscle strength

A person with very strong glabellar muscle activity may experience a different duration than someone with relatively mild muscle activity.

Dose and treatment plan

The treatment plan is individualized based on the product and treatment area.

Injection technique

Precise placement matters.

How “duration” is defined

A patient may still notice improvement even after some movement has returned.

A clinical trial may define the end of treatment effect using a specific validated measurement or retreatment criterion.

These aren’t necessarily the same thing.

What Is the Difference Between Onset, Peak Effect and Duration?

These terms are often mixed together online.

Onset

When you first begin noticing an effect.

For Letybo, the median onset was 3 days in the Phase III trial.

Peak effect

When the treatment has reached its strongest noticeable effect.

This is not necessarily the same day that treatment begins working.

Duration of meaningful improvement

How long the patient continues to experience a clinically meaningful benefit.

Time to retreatment

How long it takes before the patient meets criteria or chooses to receive another treatment.

These four measurements can produce different numbers.

That is why asking simply “How many months does Letybo last?” doesn’t tell the whole story.

What Happens When Letybo Starts Wearing Off?

Letybo does not normally “switch off” suddenly.

The effect gradually diminishes as normal communication between nerves and muscles recovers.

Patients may notice:

1. Increased movement
2. Gradual return of dynamic lines
3. Increasing ability to contract the treated muscles
4. Progressive return toward the pre-treatment appearance

This process varies between individuals.

The American Academy of Dermatology describes botulinum toxin’s effect as temporary and notes that facial-line improvement generally lasts approximately 3–4 months, sometimes longer.

Does Letybo Make Wrinkles Worse When It Wears Off?

No.

The underlying muscle activity gradually returns toward its pretreatment state.

Patients sometimes perceive wrinkles as more noticeable after treatment because they have become accustomed to seeing a smoother appearance.

That is different from Letybo causing the wrinkles to become worse.

Does Repeated Letybo Treatment Make It Last Longer?

It may change the treatment experience over time, but there is not enough evidence to promise that repeated Letybo injections will necessarily last longer for every patient.

The Phase III Letybo study included repeated treatment during its extension phase, allowing researchers to evaluate longer-term safety and efficacy.

However, patients should not be told that simply receiving more treatments guarantees progressively longer duration.

Individual response remains important.

Does the Amount of Letybo Affect How Long It Lasts?

Dose can influence the degree and duration of botulinum toxin effect, but more is not automatically better.

Letybo’s FDA-approved regimen for glabellar lines is 20 Units administered across five injection sites.

A clinician may determine the appropriate treatment plan based on the patient’s anatomy and treatment goals.

It is important not to compare Letybo units directly with Botox units. Botulinum toxin products have product-specific potency units, and the FDA labeling warns against treating units from different products as interchangeable.

Can You Get Letybo Again Before It Completely Wears Off?

Treatment timing should be determined by the prescribing clinician.

The Letybo clinical study used a minimum interval of 12 weeks before retreatment and required participants to meet predefined criteria for retreatment.

Patients should not schedule repeated injections simply because they want to maximize duration or prevent every bit of movement from returning.

A qualified healthcare professional should determine whether additional treatment is appropriate.

How Often Can You Get Letybo?

For cosmetic treatment, the appropriate interval depends on the patient’s response and the treating clinician’s assessment.

The clinical-trial protocol required at least 12 weeks between treatments.

The FDA prescribing information also emphasizes that Letybo is a prescription botulinum toxin product and includes important safety warnings.

The practical principle is:

Do not assume that more frequent treatment produces better or longer-lasting results.

Your clinician should determine the appropriate timing.

What Factors Can Affect How Long Letybo Lasts?

There is no single duration that applies to everyone.

Factors that may influence the apparent duration of treatment include:

Facial anatomy

Muscle size, strength and activity vary substantially between individuals.

Treatment area

Different muscles can respond differently.

Degree of muscle activity

Patients with highly active muscles may perceive the return of movement differently.

Treatment plan

The product, dose, injection pattern and treatment objective all matter.

Individual response

Patients respond differently to botulinum toxin products.

How the patient defines “wearing off”

One person may consider the treatment finished when any movement returns.

Another may still consider the treatment successful as long as wrinkles remain substantially softened.

Does Exercise Make Letybo Wear Off Faster?

There is a great deal of anecdotal discussion online about exercise and botulinum toxin duration.

However, patients should be cautious about assuming that exercise automatically causes Letybo to wear off faster.

There isn’t strong evidence establishing that ordinary exercise reliably shortens the duration of cosmetic Letybo treatment.

Patients should follow their clinician’s specific post-treatment instructions rather than relying on social-media claims.

What Does the Evidence Show vs. What Is Clinical Experience?

This distinction is important.

What the evidence shows

• Letybo is FDA approved for temporary improvement of moderate-to-severe glabellar lines in adults.
• A Phase III trial found a median onset of 3 days.
• The same study found an average time to first retreatment of approximately 127 days.
• Treatment effect remained statistically significant compared with placebo through 16 weeks.
• Botox studies also demonstrate several months of benefit, with a pooled median duration of 120 days at maximum contraction in one meta-analysis.
• The AAD describes botulinum toxin effects for facial lines as generally lasting approximately 3–4 months, sometimes longer.

What can vary

• Onset
• Peak appearance
• Duration
• Degree of movement
• Patient satisfaction
• Timing of retreatment

What should not be promised

No provider should guarantee that Letybo will last:

• Exactly 3 months
• Exactly 4 months
• 5 months
• 6 months

for every patient.

The evidence supports a range of individual responses, not a guaranteed expiration date.

So, How Long Should You Expect Letybo to Last?

For a patient considering Letybo for glabellar lines, a reasonable evidence-based expectation is:

Expect several months of improvement, with approximately four months being a useful clinical benchmark—but individual duration can be shorter or longer.

The Phase III study’s average time to first retreatment was approximately 127 days, while the American Academy of Dermatology describes botulinum toxin results more generally as lasting about 3–4 months, sometimes longer.

That is much more accurate than claiming that every patient will get exactly four months of results.

Is Letybo Worth It If It Only Lasts a Few Months?

For many patients, the value of treatment is not simply the number of days it lasts.

Patients may consider:

• How much the wrinkles bother them
• How natural the result looks
• How predictable the response is
• How often they want maintenance treatments
• The cost per treatment
• The quality of the treatment experience
• The expertise of the injector

A treatment that produces a natural result and meets the patient’s goals may be valuable even though the effect is temporary.

Letybo vs. Botox: Which Lasts Longer?

The most accurate answer is: there is no proven universal winner.

The available clinical data show similar time frames measured in months, but the studies were not designed in a way that allows us to declare that Letybo always outlasts Botox.

For glabellar lines:

Letybo: approximately 127 days average to first retreatment in one Phase III study.

Botox: approximately 120 days median duration at maximum contraction in a pooled analysis of four trials among Day-30 responders.

Those numbers are close enough that it would be inappropriate to market either product as definitively longer-lasting based solely on these studies.

What Is More Important Than the Brand?

For many patients, the quality of the treatment plan may matter more than trying to identify a universal “longest-lasting” neuromodulator.

A skilled injector considers:

• Your facial anatomy
• Which muscles are creating the lines
• The strength of those muscles
• Your desired amount of movement
• Your previous treatment history
• The treatment area
• Appropriate dosing
• Injection placement
• Facial balance

The American Academy of Dermatology emphasizes the importance of choosing a qualified provider with appropriate knowledge and experience with botulinum toxin injections.

Considering Letybo in Bethlehem, PA?

If you’re considering Letybo or Botox in the Bethlehem, Pennsylvania area, a consultation can help determine which treatment is appropriate for your specific facial anatomy and goals.

At Azani Medical Spa, treatment decisions are individualized rather than based solely on which product is advertised as lasting the longest.

Dr. Monica Gavin, MD, and the clinical team can discuss your goals, previous neuromodulator experience and treatment options and develop an individualized plan.

Medical References

FDA

FDA Letybo Prescribing Information — indication, dosing, warnings and safety information.

American Academy of Dermatology

Botulinum Toxin Therapy: Overview — expected onset and typical duration of botulinum toxin treatment.

Botulinum Toxin Therapy: FAQs — duration, retreatment and treatment expectations.

Peer-Reviewed Research

Mueller DS, et al. Efficacy and Safety of Letibotulinumtoxin A in the Treatment of Glabellar Lines: A Randomized, Double-Blind, Multicenter, Placebo-Controlled Phase 3 Study. Aesthetic Surgery Journal. 2022.

Glogau R, et al. OnabotulinumtoxinA: a meta-analysis of duration of effect in the treatment of glabellar lines. Dermatologic Surgery. 2012.

About the Medical Reviewer

Monica Gavin, MD

Medically reviewed by Monica Gavin, MD

Dr. Monica Gavin is a physician at Azani Medical Spa in Bethlehem, Pennsylvania. She earned her MD from Wayne State Medical School and provides physician-led medical care at Azani Medical Spa.

Last medically reviewed: August 2026

Medical content notice: This article is intended for educational purposes and does not replace an individualized medical consultation. FDA labeling and clinical evidence can change. Medical content should be periodically reviewed and updated when significant new evidence or regulatory information becomes available.