How Long Does Botox Last? Duration Data by Area, Explained from the Literature

How long does Botox last? Duration data by area, explained from the literature

"About three months, I'd say" — you are surely no longer satisfied with this answer your clinic gives.

That's because what you really want to know is the concrete number: "for my own area, at my own sex, using which product, how many weeks will it last?"

In fact, the medical literature has already given that answer. For the glabella, up to 24.2 weeks. For the crow's feet, up to 157 days. For the area around the mouth, combining hyaluronic acid extends the duration bymore than 1.5 times— all of this is data from peer-reviewed clinical studies.

In this article, we explain the following four points using only data from the literature:

• The basic mechanism of action of Botox (botulinum toxin) and the mechanism by which the effect wears off
• The detailed duration of effect by area: glabella, crow's feet, forehead, around the mouth, masseter (jaw angle), and so on
• How the duration changes depending on the dose (number of units) and the type of product
• Differences in duration of effect by sex

For those who cannot accept "it depends on the person," we thoroughly explain Botox duration by area and by product, using only data from trustworthy medical papers and systematic reviews from around the world.

In the first place, why does the effect wear off? — The mechanism of action and the mechanism of duration

If you don't understand this, you'll never understand "why mine alone wears off quickly."

When BontA is injected into a muscle, the toxin diffuses to and binds at the nerve terminal, preventing the release of the neurotransmitter acetylcholine. This inhibits the action at the neuromuscular junction, so that the muscle no longer contracts and expression lines (dynamic wrinkles) are no longer formed (Berry 2012).

Complete absence of muscle activity occurs about 5 to 15 days after injection (Berry 2012). Because the specific facial muscles no longer contract, you can feel that the wrinkles have decreased (Fagien 2003).

So why does the effect wear off after a few months?

The answer is simple — because the nerve "regenerates." Muscle atrophy from the chemical effect triggers a regenerative process known as "sprouting" at the nerve terminals. This regenerative process lasts 120 days, creating new terminals at the neuromuscular junction and ultimately restoring muscle activity. Because of this mechanism, the duration of clinical therapeutic effect usually falls in the range of 3 to 6 months (Berry 2012).

Now that we've grasped the mechanism, let's finally look at the concrete numbers by area.

[Glabella] The area with the most abundant research data — 17.6 to 24.2 weeks

One of the most common treatment areas in aesthetic medicine (Cochrane Review 2021) is the glabellar lines. As a result, the data are also the most extensive.

First, let me dismantle what you think is "common sense."

Is "high dose = longer lasting" true? Comparison data from 20U to 80U

Quadruple the dose, and the duration quadruples too — unfortunately, that's not how it works. The numbers make it clear at a glance.

• OnabotulinumtoxinA 20U(Carruthers 2005b): mean duration 17.6 weeks
• Same product 40U(Carruthers 2005b): 21.7 weeks
• Same product 60U(Carruthers 2005a): 22.8 weeks
• Same product 80U(Carruthers 2005a): 24.2 weeks

Even quadrupling the dose from 20U to 80U only extends the duration from 17.6 weeks to 24.2 weeks. In other words, while administering a high dose does make the effect last longer, it does not dramatically double it. It's not as simple as "the more you inject, the longer it lasts."

Differences in glabellar duration by type of product

Next, the data by product. There are multiple Botox products, and duration data have been reported for each.

IncobotulinumtoxinA (XEOMIN®, etc.)
The duration was 20.8 weeks (146.12 days) for women and 17.3 weeks (121.14 days) for men. In the same study, the duration of OnabotulinumtoxinA was 20 weeks (140.65 days) for women and 16.6 weeks (Rappl 2013) (116.61 days) for men, so the two products show very similar durations.

AbobotulinumtoxinA (Dysport®, etc.)

• In a study compared with placebo, the median duration was12 weeks(Brandt 2009) (85 days)
• In another study,15.3 weeks(Kane 2009) (107 days)
• In yet another study, the median duration of effect was117 days(Monheit 2019)

DaxibotulinumtoxinA
With administration of 60U, the duration of effect was reported to reach22.5 to 23.2 weeks. For the same product, 20.8 weeks at 20U and 22.80 weeks at 40U (Carruthers 2017) were shown, indicating a long-lasting effect.

NewBontA (Prosigne®, etc.)
The duration of NewBontA 20U was12 weeks(84.5 ± 38.8 days), nearly equivalent to the 12.8 weeks (89.9 ± 41.1 days) of the compared OnabotulinumtoxinA 20U (Won 2013).

[Forehead] Horizontal lines last 113 to 125 days — the dose difference is slight

Horizontal forehead lines are also a representative treatment area for Botox. As with the glabella, the more the dose, the longer it lasts, but the difference is limited.

When OnabotulinumtoxinA 40U was administered, the duration of therapeutic effect by physician assessment was118.5 days, and the duration by the patient's own assessment was125 days. On the other hand, in the group given 30U, it was113.0 daysby physician assessment and115.5 daysby patient assessment (Solish 2016).

The difference between 40U and 30U is only 5 to 10 days. Here, too, the relationship between dose and duration is not a "dramatic proportional relationship."

[Crow's feet] Laugh lines last up to 157 days — there are Japanese data, too

The wrinkles that appear at the corners of the eyes when you laugh, the so-called "laugh lines." The data for this area actually vary considerably from study to study.

• OnabotulinumtoxinA 24U (Carruthers 2014): by physician assessment16.8 weeks (118 days), and by patient assessment16.5 weeks (116 days). In patients who showed at least a one-grade improvement from baseline, it was, by physician assessment,17.8 weeks (125 days), and by patient assessment,20.5 weeks (144 days)
• . In another study, the duration of effect of OnabotulinumtoxinA 24U (Wu 2019) was, by both physician and patient assessment, about150 to 157 days
• In a study targeting Japanese patients,the duration of OnabotulinumtoxinA 24U (Harii 2017) was about95 days(85 days at 12U).

The figure of about 95 days shown by the Japanese data is short compared with the more than 150 days of the overseas data. This may be influenced by differences in physique and muscle mass. Remember that the data you should refer to as your own are data from the same ethnicity.

[Around the mouth] On its own, 9.9 weeks — but combined with hyaluronic acid, 15.5 weeks

Here, let's talk about a combination that costs you if you don't know it.

The wrinkles around the mouth last somewhat shorter than at other areas — this is a fact. When OnabotulinumtoxinA was administered alone at 9U (Carruthers 2010), the mean duration of effect was9.9 weeks(69.3 ± 11.0 days).

However, when hyaluronic acid (such as JUVEDERM ULTRA®) was used together with the same 9U of OnabotulinumtoxinA, the duration was greatly extended to15.5 weeks(108.9 ± 12 days) (Carruthers 2010).

9.9 weeks → 15.5 weeks. About a56% extension.

For deep wrinkles around the mouth, the combination treatment of Botox, which suppresses muscle movement, and hyaluronic acid, which fills the groove, is very effective. Those who are trying to treat the wrinkles around the mouth with "Botox alone" would do well to once ask their physician about the possibility of combining the two.

[Jaw angle (masseter)] Be careful with repeated injections — there are data showing function does not recover even after 6 months

Botox to the jaw angle carries a risk that other areas do not. Those who repeat injections without knowing this, please don't skip ahead.

Botox injection for the jaw angle (masseter hypertrophy) is very popular for the purpose of slimming the face by sharpening the facial contour, and for the purpose of treating teeth grinding and clenching. However, injection into the masseter has caveats that differ from other areas.

Single injection versus repeated injection — the serious difference the data show

In a clinical trial of 26 women (Souza Nobre 2024), 75U (Souza Nobre 2024) of Abobotulinumtoxin was administered to each masseter. A single low-dose BontA injection is thought not to have a permanent effect on muscle thickness, and assessment by ultrasound also confirmed thatthe thickness had begun to recover 3 months (Souza Nobre 2024) later.

Here is the important part.

In the group that received an additional booster injection 3 months (Souza Nobre 2024) after the first injection, even after 3 months had passed from the second injection (6 months in total from the first),the muscle thickness did not return to normal(Souza Nobre 2024). It has been pointed out that this may be the result of incomplete recovery of innervation or progression of muscle fiber atrophy.

Long-term effect on chewing function — "biting force" does not return for over six months

Occlusal force (biting force), too, with a single injectiongradually returns to normal in 3 months (Souza Nobre 2024). However, when an additional injection was given 3 months later,muscle activity did not recover even at the 6-month follow-up(Souza Nobre 2024). Also, regarding chewing performance (the ability to crush food), in both the single injection and the additional injection 3 months later,function remained reduced throughout the 6-month follow-up period(Souza Nobre 2024).

When Botox is repeatedly injected into the masseter for cosmetic purposes alone, functional adverse effects such as muscle atrophy and reduced chewing function may persist for a long time, so the treatment interval requires ample caution.

Another factor that governs duration — "sex" changes it by about 25 days

It is not only area and product that determine duration. Whether you are male or female also greatly changes the duration of effect.

Generally, men have more developed muscles and greater strength than women. This fact may directly affect the number of units of BontA needed to treat wrinkles, and the duration of effect (Cochrane Review 2021).

Looking at the numbers, the difference is clear at a glance.

In the group given IncobotulinumtoxinA, the duration of therapeutic effect was146.12 days in women, whereasin men it was 121.14 days, about 25 days shorter. Similarly, in the group given OnabotulinumtoxinA,the duration in women was 140.65 days, whereasin men it was 116.61 days(Rappl 2013), such results were obtained.

To the men who had felt "why do I feel like mine wears off quickly" — that is not your imagination but data backed by the literature. In the case of men, there are cases where a higher-than-usual dose or treatment at shorter intervals becomes necessary.

Summary: a list of duration data by area

Having read this far, you no longer need to be misled by the vague words "it depends on the person." Finally, let us organize the facts the literature shows.

• Glabellar lines: It varies by dose, but it generally lasts about 17 weeks (Carruthers 2005a) to 24 weeks (Carruthers 2005a). Administering a high dose (80U) makes it last 24.2 weeks, but it is not completely proportional to the dose.
• Crow's feet: It generally lasts about 16 weeks (116 to 118 days) to 20 weeks (about 144 days) (Carruthers 2014).
• Forehead lines: With administration of 30U to 40U, it lasts about 113 to 125 days (Solish 2016).
• Wrinkles around the mouth: With Botox alone it is relatively short at 9.9 weeks, but using hyaluronic acid together can extend the duration by about 56% to 15.5 weeks (Carruthers 2010).
• Jaw angle (masseter): With a single injection it begins to recover in about 3 months, but if injections are repeated at short intervals, adverse effects such as muscle atrophy and reduced chewing function may persist for over 6 months (Souza Nobre 2024).
• The effect of sex: Because men have stronger muscle force, there is a tendency for the duration of Botox effect to be about 25 days shorter in men than in women (Rappl 2013).

Botox is a safe and effective treatment, but by understanding its mechanism of action, the characteristics by area, and even the strength of your own muscles (sex, etc.), you can draw up a more satisfying treatment plan. At your next clinic visit, please refer to these data and discuss an appropriate dose and treatment schedule with your physician.

If you find yourself thinking, "What about my case?"

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References

1. Gostimir M et al. Safety of Botulinum Toxin A Injections for Facial Rejuvenation: A Meta-Analysis of 9,669 Patients. Ophthalmic Plast Reconstr Surg. 2023
2. Carruthers J, Carruthers A. Botulinum toxin type A treatment of multiple upper facial sites: patient-reported outcomes. Dermatol Surg. 2007
3. Carruthers J et al. Injectable daxibotulinumtoxinA for glabellar lines. Dermatol Surg. 2017

Author of this article

Hiromitsu Nakamura Ginza Clinic Physician

Zetith Beauty Clinic Ginza, Osaka Shinsaibashi, and Fukuoka clinics

He has a track record of research presentations at domestic and international academic conferences, and is also engaged in technical guidance and education for Zetith Beauty Clinic as a whole. He specializes in precise aesthetic medicine based on anatomical grounds, pursuing natural results tailored to each person's bone structure and tissue.