Expert Insights on Medical Aesthetics

Discover the Top 3 Reasons Why Botox seem to work less with time or does not last as long


‘Doctor Wong, why does my Botox seems to last shorter and shorter? Do I need a higher dose?’

This is a question I get asked a lot in my daily clinical practice which frustrates many customers and even myself. 

 I wish to write about this pretty complex and mystifying topic so that more people can understand it better.

There are three causes why this interesting phenomenon occurs, two of which are more common than the last. Let’s start with the more common reasons first. 

1) There are other factors responsible for wrinkle formation

With mainstream acceptance, people tend to start Botox at a younger age. From our late twenties to thirties, the main cause of wrinkles is muscle movement. Hence, when Botox relaxes the muscles, wrinkles disappear rapidly as skin quality is still good.

However, as we grow older, sun damage and age-related loss of collagen and elastin spoils the party by hastening skin laxity. It’s important to note that Botox only relaxes muscle and has no direct beneficial effect on skin laxity. As a result, its apparent effect will seem less with time as other factors not improved by Botox come into play. 

In order to combat wrinkle formation and worsening laxity, some practitioners and patients choose to increase the dosage of Botox. A higher dose relaxing the facial muscles too much risks giving a ‘frozen’ or unnatural look. This gives Botox a bad reputation when it is not its fault that aesthetic doctors do not explain this phenomenon clearly to patients!

This is not a strategy we adopt at SL Aesthetic Clinic. Instead, we suggest regular Botox doses to relax muscles, and also concurrent skin tightening treatment which improves skin quality and tautness. This treats both causes of wrinkles – muscle activity and skin laxity. Some examples of skin tightening treatmentsUltimate Guide to the Best Non-Surgical Face Lifting in Singapore: Fotona5D vs Fotona4D vs Thermage FLX vs Ultherapy vs HIFU available at SL Aesthetic Clinic include Fotona5D, Thermage FLX, HIFU and Ultherapy.

That being said, we must realize that we can never win the fight against time. There will still be some wrinkles with age. Fortunately, those who choose to do recommended aesthetic treatments will look better than others who do not. 

2) The difference between static and dynamic wrinkles

This is a more difficult concept to grasp but I will try to explain this as simply as I can. 

When customers choose to do their first Botox treatment, most of them would typically have some static wrinkles. Static wrinkles are wrinkles which are present at rest, as opposed to dynamic wrinkles which appear when we make certain expressions. 

Static wrinkles do not form overnight. They take years to form as the dynamic wrinkles carve it deeper and deeper into the skin each day. These are also the wrinkles which patients notice, driving them to seek their first Botox treatment. 

After the first Botox treatment, they see a huge improvement in their static wrinkles and some may even feel that their single Botox treatment can last a year (or more!). Some mistakenly choose to wait till their static wrinkles reappear before they do their next treatment. This is not ideal as Botox can only last 4 to 6 months, and should be done as soon as muscle activity returns. 

Subsequently, these customers may then start to notice their dynamic wrinkles instead of their now gone static wrinkles, and as static wrinkles take years to form as opposed to dynamic wrinkles (which correlates to muscle activity), they may misunderstand that Botox seem to work for a shorter period now when all along, Botox really only relaxes muscles for 4 to 6 months!

To put it simply, Botox predictably only lasts for 4 to 6 months. To get the best results out of Botox, do it once dynamic wrinkles reappear, and not only after static wrinkles form. 

3) Formation of antibodies

As the use of Botox use soared worldwide, doctors and researchers are realizing that resistance to Botox can develop, and some patients may even be totally immune to its beneficial effects.

As Botox is considered a foreign protein, neutralizing antibodies can form against it. Much like antibodies which are produced against viruses such as COVID-19, antibodies specifically attach to Botox. These antibodies inactivate Botox, diminishing its therapeutic effect on muscles partially, or even completely. 

Simply put, Botox resistance does occur in some patients. According to scientific studies, the numbers are thankfully low – between 1% to 3% of patients who use Botox will develop antibodies. 

These numbers are seen in patients receiving Botox for muscle disorders such as cervical dystonia (tight neck muscles). Thankfully, the incidence of Botox resistance is even lower in patients who use it for cosmetic purposes. This is because the dosage and frequency of Botox used for aesthetic purposes are typically lower and less frequent than for neuromuscular disorders. 


Naumann M, Boo LM, Ackerman AH, Gallagher CJ. Immunogenicity of botulinum toxins. J Neural Transm (Vienna). 2013;120(2):275-90. doi:10.1007/s00702-012-0893-9

Interested in this treatment? WhatsApp us today!


Share on facebook
Share on whatsapp
Share on telegram
Share on email

Related Articles