More Isn't Always Better: A Balanced Approach to Forehead Neurotoxin Treatment
Botulinum toxin treatments such as Botox® have become so routine in aesthetic medicine that treating the forehead can sometimes appear as simple as following an injection pattern. In reality, the forehead is one of the areas where individualized assessment matters most.
Not every forehead should be treated the same way, and completely eliminating movement is not necessarily the goal for every patient.
The frontalis muscle has an important function: it elevates the eyebrows. Its strength, shape, pattern of movement, and relationship with the muscles that depress the brow vary from patient to patient. Brow position, eyelid anatomy, forehead height, muscle strength, existing asymmetry, and even the way a patient recruits the frontalis to compensate for a heavier brow or upper eyelid can influence how the forehead should be treated.
Published literature supports an individualized approach to forehead neurotoxin treatment based on facial anatomy, muscle mass, muscle tone, symmetry, and patterns of movement rather than relying on a single injection pattern for every patient.¹
Muscle Movement Has a Purpose:
Botulinum toxin temporarily reduces muscle activity by inhibiting acetylcholine release at the neuromuscular junction. In aesthetic treatment, reducing repetitive muscle contraction can soften dynamic lines and create a smoother appearance.
But reducing movement and eliminating movement are not necessarily the same goal.
The frontalis is the primary elevator of the brow. Because it works in balance with the muscles that depress the eyebrows, weakening it excessively can alter brow position or contribute to an unnatural or heavy appearance in susceptible patients. Variable frontalis anatomy can also contribute to unexpected movement patterns following treatment.¹,²
Before treating a forehead, I assess the patient both at rest and in animation. I want to see how strongly the frontalis contracts, where that movement occurs, whether one side is stronger than the other, where the brows naturally sit, and whether the patient is recruiting the frontalis to help elevate the brows or upper eyelids.
This is one reason aesthetic treatment should never be reduced to simply memorizing an injection map.
What Happens to Muscle With Repeated Neurotoxin Treatment?
Botulinum toxin does more than temporarily soften a wrinkle. By reducing neuromuscular activity, it can also produce changes in the treated muscle itself.
Muscle atrophy following botulinum toxin exposure has been documented, and prolonged chemodenervation can influence muscle volume and function.³ A review examining the long-term effects of repeated cosmetic botulinum toxin treatment found evidence that changes in muscle composition, function, and appearance may sometimes persist beyond the conventional three-to-five-month period associated with the visible cosmetic effect.⁴
Our understanding of the long-term effects of decades of repeated cosmetic neurotoxin treatment is still developing. Many studies have relatively short follow-up periods, and there is not enough evidence to conclude that repeated forehead treatment directly causes thinning or laxity of the overlying skin.⁴
What we can say is that repeated chemodenervation can affect muscle size and function. What those changes mean for facial aging over decades of aesthetic treatment remains an area deserving further study.
For me, this reinforces the value of thoughtful dosing rather than assuming that more units or less movement automatically produces a better aesthetic result.
More Neurotoxin Does Not Necessarily Mean a Better Result
There can be a tendency to judge the success of a neurotoxin treatment by how completely movement disappears.
I don't believe that's always the best measure of a successful outcome.
For many patients, the goal is to soften excessive movement and dynamic lines while maintaining enough function to preserve natural expression and appropriate brow position. Recommendations for forehead treatment emphasize adjusting the treatment according to the patient's individual anatomy, muscle activity, and the desired degree of movement.¹
One patient may prefer a very smooth forehead. Another may prioritize eyebrow movement and expression. Another may already have a relatively low brow and depend heavily on the frontalis for elevation.
Those patients should not automatically receive the same treatment.
What About Neurotoxin “Resistance”?
Occasionally, patients report that their neurotoxin no longer seems to work as well as it once did.
This is sometimes referred to as secondary nonresponse, meaning that botulinum toxin previously produced the expected clinical effect but later becomes less effective. This does not necessarily mean that the patient's muscles have simply become “used to Botox.”
There are several potential explanations for an apparent loss of effect, including dose, injection technique, product handling, anatomy, treatment expectations, treatment intervals, and true immunologic resistance.
Neutralizing antibodies against botulinum toxin are one possible cause of secondary nonresponse, although antibody formation is relatively uncommon overall. A systematic review found a low overall incidence of neutralizing antibodies following botulinum toxin type A treatment, although much of the evidence includes therapeutic indications in which doses and treatment patterns may differ substantially from aesthetic use.⁵
More recent literature examining secondary nonresponse in aesthetic medicine has identified factors such as higher cumulative exposure, short treatment intervals, and booster injections as potential contributors to immunogenicity.⁶
This is another reason I believe touch-ups should have a clinical reason rather than simply becoming routine. Additional treatment should be based on assessment of the patient's movement and result, not an automatic attempt to eliminate every remaining bit of motion.
Are All Neurotoxins the Same?
Several botulinum toxin type A formulations are available for aesthetic use. Although they act through the same basic mechanism, the products are not identical. They differ in formulation, manufacturing, purification, protein composition, dosing, and other characteristics.
IncobotulinumtoxinA (Xeomin®), for example, is formulated without complexing proteins. Differences among formulations have generated ongoing research into whether protein composition and cumulative exposure may influence immunogenicity and secondary treatment failure.⁵,⁶
This does not mean that patients routinely develop antibodies to other neurotoxins or that one product can be considered completely immune from the possibility of treatment failure. Clinically significant immunogenicity remains uncommon.
However, treatment history, product selection, dosing, and treatment frequency can become relevant considerations when evaluating a patient who reports an unexplained decrease in treatment response.
The Patient You Treated Five Years Ago May Not Be the Same Patient Today
This may be one of the most overlooked aspects of long-term aesthetic care.
Faces change.
Aging affects bone, fat, muscle, skin, and soft tissue. Patients gain or lose weight. Medications change. Medical conditions develop. Hormonal changes occur. Brow and eyelid position can change. Previous surgery and aesthetic procedures can alter anatomy.
A treatment plan that worked beautifully for someone several years ago should not automatically be repeated indefinitely without reassessment.
Every appointment gives us another opportunity to look at the patient's face as it exists today.
Sometimes that means adjusting the dose or injection pattern. Sometimes it means accepting a little more movement. And sometimes the concern a patient sees is no longer primarily caused by muscle activity, which means additional neurotoxin may not be the appropriate solution.
A Balanced Approach to Forehead Treatment
After decades in nursing, surgery, and aesthetic medicine, I have become increasingly convinced that good aesthetic treatment isn't about how much product we can inject or how completely we can eliminate a wrinkle.
It is about understanding what we are treating and why.
Forehead neurotoxin treatment should consider anatomy, muscle strength, brow position, facial expression, previous treatment response, age, and the patient's individual goals. The medical literature consistently emphasizes the variability of forehead anatomy and the importance of adapting treatment to the individual patient.¹,²
Sometimes that means using less.
Sometimes it means changing injection placement.
Sometimes it means treating a different combination of muscles.
And sometimes it means recognizing that more neurotoxin isn't the answer.
Natural-looking aesthetic medicine requires reassessment, restraint, and adaptability. The goal isn't simply a forehead that doesn't move.
The goal is a result that makes sense for the person wearing it.
References
Anido J, Arenas D, Arruabarrena C, et al. Tailored botulinum toxin type A injections in aesthetic medicine: consensus panel recommendations for treating the forehead based on individual facial anatomy and muscle tone. Clin Cosmet Investig Dermatol. 2017;10:413-421. doi:10.2147/CCID.S138274.
Walker B, Hand M, Chesnut C. Forehead movement discrepancies after botulinum toxin injections: a review of etiology, correction, and prevention. Dermatol Surg. 2022;48(1):94-100. doi:10.1097/DSS.0000000000003218.
Durand PD, Couto RA, Isakov R, et al. Botulinum toxin and muscle atrophy: a wanted or unwanted effect. Aesthet Surg J. 2016;36(4):482-487. doi:10.1093/asj/sjv208.
Crook JL, Hamidian Jahromi A, Konofaos P. Long-term effects of repeated botulinum toxin injection in cosmetic therapeutics. Ann Plast Surg. 2022;88(3):345-352. doi:10.1097/SAP.0000000000002994.
Rahman E, Alhitmi HK, Mosahebi A. Immunogenicity to botulinum toxin type A: a systematic review with meta-analysis across therapeutic indications. Aesthet Surg J. 2022;42(1):106-120. doi:10.1093/asj/sjab058.
Kroumpouzos G, Silikovich F. Exploring nonresponse to botulinum toxin in aesthetics: narrative review of key trigger factors and effective management strategies. JMIR Dermatol. 2025;8. doi:10.2196/69960.
Medical Disclaimer: This article is intended for educational purposes and does not replace an individualized medical consultation. Treatment recommendations, dosing, product selection, and injection technique should be determined by an appropriately licensed healthcare professional following assessment of the individual patient.
