The "11s" or "elevens" refer to the paired vertical lines that form between the eyebrows, caused by repeated contraction of the procerus and corrugator supercilii muscles. Anti-wrinkle injections to the glabellar complex are the standard approach, assessed individually at consultation.
The colloquial name “11s” comes from the shape these lines make between the brows, two roughly parallel vertical creases that, at their most visible, resemble the number eleven. You may have heard them called “elevens,” “glabellar lines,” or simply “frown lines between the eyes.” Whatever the name, they form from the same anatomical source: a group of muscles in the central forehead and brow that pull inward and downward during concentration, squinting, and emotional expression.
At Core Aesthetics in Oakleigh, assessment of the glabellar area is one of the more clinically involved parts of the upper face, because several muscles work in overlapping patterns here. Understanding which muscles are dominant, how deep any resting lines have become, and what the surrounding facial anatomy looks like all inform what an appropriate treatment plan might involve, and whether treatment is the right step at all.
The "11s" Label: From Colloquial Term to Clinical Anatomy
The term “11s” entered common use because of a simple visual observation: when the corrugator and procerus muscles contract together, the lines that form between the brows can resemble the number eleven, two roughly parallel vertical marks sitting side by side. The name has no clinical origin; it emerged in patient conversation and online discussion as a more memorable shorthand than “glabellar lines” or “corrugator-mediated dynamic rhytids.” It stuck because it works as a description.
What the nickname captures well is the appearance. What it can inadvertently obscure is the anatomy. Referring to the “11s” as a single thing can suggest a single, simple treatment target, when in practice the glabellar complex involves at least two distinct muscle groups, the corrugators and the procerus, each with its own position, direction of pull, and contribution to the overall crease pattern. The “elevens” that one person describes may be predominantly corrugator-driven; in another, the procerus creates an additional horizontal component that changes the assessment significantly.
At Core Aesthetics, the consultation starts with your language, whatever you call them, and then maps that concern to the underlying anatomy. The nickname is a useful way to open the conversation. The anatomy is what guides the treatment plan.
The Muscles Behind the 11s: Procerus and Corrugators
Two muscle groups create the glabellar complex responsible for the “11s” appearance. The procerus runs vertically from the nasal bridge upward, pulling the inner brow down and contributing a horizontal crease at the root of the nose. The corrugator supercilii muscles, one on each side, run diagonally from the inner brow toward the middle of the forehead, drawing the brows inward and downward. Their contractions create the paired vertical creases.
Most people have some natural dominance in one muscle group over the other, which is why the “11s” rarely look symmetrical on close inspection. One side may be deeper, higher, or more angled than the other. This variation matters clinically: treating the corrugators without accounting for the procerus, or vice versa, can produce uneven results or allow one set of lines to persist while the other softens. A thorough assessment maps the movement of both before a treatment approach is decided.
Why the 11s Develop, and Why Some People Get Them Earlier
Repeated facial expression is the primary driver. Every time you concentrate, squint against the sun, or furrow in frustration, the glabellar muscles contract. Over tens of thousands of repetitions, across years, the skin above these muscles begins to crease. Initially the lines are “dynamic,” appearing only with movement and disappearing at rest. Over time, if the pattern continues, they can become “static”, visible even when the face is relaxed.
Several factors influence how quickly this progression happens. Genetics play a significant role; some people inherit stronger corrugators or thinner overlying skin, and will develop visible 11s earlier regardless of sun exposure or expression habits. Cumulative UV exposure accelerates the breakdown of collagen and elastin in the skin, reducing its capacity to spring back between expressions. Habitual squinting, from screen use, outdoor time without sunglasses, or uncorrected vision, increases the frequency of contraction. Sleep position, while harder to change, can also concentrate crease patterns when the face is repeatedly pressed against a pillow on the same side.
Dynamic vs Static 11s: Understanding Which Stage You Are At
The clinical distinction between dynamic and static lines is one of the most important in treatment planning. Dynamic lines appear when you move, when you frown, squint, or concentrate, and resolve completely when your face is at rest. At this stage, the concern is primarily preventive: reducing the frequency and depth of the crease before it has a chance to etch into the skin permanently. Anti-wrinkle injections work most efficiently here, because the muscle activity causing the line is still the dominant factor.
Static lines are present regardless of expression. They represent the accumulated effect of years of movement on the skin structure itself. Treatment can still soften their appearance by reducing ongoing muscle tension, but the skin component, the actual crease, may persist to some degree and may benefit from complementary approaches discussed at consultation. Setting appropriate expectations is part of the initial conversation at Core Aesthetics; the goal is to give you an accurate picture of what is and is not within the scope of any single treatment approach.
How the Glabellar Area is Assessed
During the initial consultation at Core Aesthetics, the glabellar assessment involves several components. You will be asked to demonstrate a range of expressions, frowning, squinting, concentrating, raising your brows, so the movement patterns of the procerus and corrugators can be observed and mapped. The resting position of the brows is noted, because treating this area without accounting for brow position can shift the resting height of one or both brows in ways that may not align with your aesthetic goals.
The skin quality in the area is also assessed. If static lines are present, their depth, direction, and the degree to which they soften when the skin is manually relaxed can indicate how much of the line is muscle-driven versus structural. Any asymmetry between the two sides is documented and discussed, because what appears as an asymmetric “11” may reflect an underlying asymmetry in muscle anatomy or brow position that treatment needs to account for rather than inadvertently correct in the wrong direction. This level of assessment takes time and is why the initial consultation at Core Aesthetics is conducted before any treatment is offered or recommended.
The Treatment Approach at Core Aesthetics
Anti-wrinkle injections to the glabellar complex work by temporarily reducing the activity of the muscles responsible for the creasing pattern. The approach at Core Aesthetics is conservative and anatomy-led: the objective is to reduce the movement that is driving the lines without eliminating all expression in the area. Most people want to look less furrowed or tense at rest, not to lose the ability to show concentration or concern altogether.
Treatment to the glabellar area is typically coordinated with an assessment of the full upper face. The corrugators, procerus, and frontalis (the forehead muscle) all interact: changing the activity level in one can affect the others. For example, reducing corrugator and procerus activity while leaving an overactive frontalis untreated can increase the upward pull on the brow. Whether treatment should address only the 11s or extend to the broader upper face is an individual clinical decision made at consultation, and not assumed in advance. The number of injection points and the placement within each muscle group vary from person to person and are documented in your treatment record.
After Treatment, What Changes and When
Following treatment to the glabellar complex, the reduction in muscle activity occurs gradually rather than immediately. The onset of effect typically begins within two to four days, with the full result visible at two weeks. This is why Core Aesthetics schedules a review appointment at approximately two weeks after treatment, to assess the distribution of effect, whether any asymmetry has emerged, and whether any fine-tuning is appropriate.
During the early post-treatment period, it is common to notice the muscles attempting to engage but producing less movement than usual, or a sensation of mild heaviness in the area. This generally resolves as the treatment takes effect and the sensation of reduced resistance normalises. The skin over the treated area does not immediately smooth, particularly if static lines are present, but reduced ongoing movement means the crease is no longer being reinforced, allowing the skin to begin recovering over the treatment interval. Patients are advised to avoid vigorous exercise for the remainder of the treatment day and to remain upright for several hours following injection.
How Long Treatment Lasts and the Maintenance Rhythm
For most people, the effect on glabellar activity lasts between three and five months, with significant individual variation. Factors that influence duration include the density of the muscle tissue being treated, the metabolic rate of the individual, and how frequently the area has been treated previously, consistent treatment over several cycles tends to produce longer-lasting effects, as the muscles being used less frequently undergo gradual atrophy of their most active fibres.
A sustainable maintenance rhythm for the 11s typically involves two to three treatment sessions per year, though this is established based on your individual response rather than prescribed in advance. At the two-week review, the baseline for your next treatment cycle is documented. When you notice the muscles beginning to recover their full range of movement, the “wearing off” signal, that is the appropriate time to plan the next appointment. Allowing significant time between treatments, particularly in the early stages, means the progressive benefits of consistent management are less likely to accumulate. Core Aesthetics can help you establish a schedule that suits both your response pattern and your practical availability.
Treating Early 11s vs Established Lines: Different Goals
The clinical conversation is different depending on which stage you are presenting at. If the 11s are still predominantly dynamic, visible only with expression, the primary goal is to interrupt the cycle of repeated muscle contraction before the lines become structurally embedded. At this stage, outcomes from treatment tend to be cleaner and the preventive benefit is greatest. Many people in their late twenties or thirties who have noticed the lines forming on expressions but not yet at rest find that consistent treatment through this window substantially delays any progression to static lines.
If established static lines are present, the goal shifts toward reducing the contribution that ongoing muscle activity makes to their visibility, rather than expecting the lines to disappear entirely. The skin component of a deep static crease reflects years of structural change, and it is important to discuss this honestly at consultation rather than allow an expectation of complete resolution to drive the treatment plan. In some cases, the combination of reduced muscle activity over time and improvements to the skin environment through appropriate skincare does produce meaningful softening of static lines, but this is a gradual process across multiple cycles, not an immediate transformation.
Why Isolated Treatment of the 11s Requires Careful Consideration
The glabellar complex does not operate in isolation. The corrugators and procerus work in balance with the frontalis and the orbicularis oculi muscles around the eyes. If the inward and downward pull of the corrugators and procerus is reduced without considering the surrounding musculature, the net forces acting on the brows can shift. In most people this produces a slight brow lift, which is generally considered aesthetically neutral or positive. In some anatomies, however, reducing glabellar activity can contribute to a brow that sits heavier or lower, particularly if there is pre-existing brow ptosis or a dominant frontalis habit of compensating for brow heaviness.
This is one reason why assessment at Core Aesthetics does not begin with a predetermined treatment formula for the “11s.” The aim is to understand the full brow and upper face architecture before deciding on approach and placement. A conservative first treatment, reviewed at two weeks and adjusted if needed, is the standard pattern, rather than a maximal-dose approach that assumes a single formula fits all glabellar presentations.
The 11s in the Context of Overall Facial Balance
For many people, the “11s” are not an isolated concern but part of a broader pattern of upper-face change. They may co-exist with horizontal forehead lines, crow’s feet at the outer eyes, a brow position that has shifted lower with age, or early volume changes beneath the brow. Assessing the 11s within this wider context shapes the treatment conversation significantly.
At Core Aesthetics, the approach aligns with the C.O.R.E. Method: the initial consultation maps the full picture before any recommendation is made. For some people, addressing the glabellar area alone achieves the primary goal. For others, a multi-area approach may better serve the result they are hoping for, but this is never assumed, never upsold, and always developed with the individual’s stated priorities at the centre. The consultation is an information-gathering and planning session, not a precursor to a predetermined treatment list. Every recommendation is built on what the full-face assessment reveals, the 11s included.
The Consultation-First Model and AHPRA September 2025 Requirements
Under AHPRA’s September 2025 guidelines for registered health practitioners performing non-surgical cosmetic procedures, practitioners must not administer a new prescription cosmetic treatment at the same appointment at which it is first proposed. This cooling-off requirement exists because cosmetic injectable treatments carry clinical risks that require individual assessment, and because the research on cosmetic decision-making indicates that patients benefit from time to consider their options without procedural pressure.
At Core Aesthetics, this model has always been the standard. Corey Anderson does not offer walk-in treatment: every new patient first attends a thorough consultation in which their concerns, anatomy, history, and goals are discussed. A treatment plan is proposed. If the patient wishes to proceed, a separate treatment appointment is scheduled. This two-appointment structure is not a bureaucratic hurdle, it is the clinical foundation that allows treatment to be tailored rather than templated, and that produces the considered, anatomy-led results that Core Aesthetics is known for.
Is This the Right Approach for You?
The best candidates for glabellar anti-wrinkle treatment are adults who have a clear, specific concern about the appearance or progression of the 11s, whether early and dynamic or more established, who understand that the treatment reduces muscle activity rather than removing lines directly, and who are comfortable with the consultation-first, low-volume, individually assessed model that Core Aesthetics operates within.
Core Aesthetics serves patients from across Melbourne’s south-east, with many travelling from Chadstone, Clayton, Bentleigh, Mount Waverley, and beyond to Oakleigh for treatment. The clinic sees a relatively small number of patients each week by design, single-practitioner, consultation-first, and unhurried. If you are looking for a practitioner who will assess your glabellar anatomy carefully, have an honest conversation about what is and is not appropriate, and build a treatment plan around your actual anatomy rather than a standard protocol, the consultation process at Core Aesthetics is designed for that.
Is this for you?
Consider booking a consultation if
- Adults 18 and over with concerns about vertical glabellar lines ("11s" or "elevens"), whether early or established
- People with dynamic glabellar lines seeking to reduce progression before lines become structural
- Those who have noticed the 11s at rest and want an honest assessment of what treatment can and cannot address
- Patients comfortable with a consultation-first, individually assessed, low-volume model of care
This may not be for you if
- People who are pregnant or breastfeeding
- Anyone with an active skin infection, inflammatory condition, or unhealed injury in the glabellar area
- Those expecting complete elimination of established static lines from anti-wrinkle treatment alone
- People with a history of neuromuscular conditions or currently taking certain medications that affect neuromuscular function, discuss at consultation
- Anyone seeking same-day consultation and treatment without a prior assessment appointment
Suitability is confirmed at consultation. This list is general guidance, not a substitute for clinical assessment.
Frequently asked questions
What exactly are the "11s" or "elevens"?
The "11s" or "elevens" are the paired vertical lines between the eyebrows, named for their resemblance to the number eleven. They form from repeated contraction of the procerus muscle (at the nasal bridge) and the corrugator supercilii muscles (across the inner brow), which pull the brows inward and downward during concentration, squinting, and frowning expressions. Initially dynamic (appearing only with movement), they can become static (visible at rest) over time.
Are the 11s the same as frown lines?
The terms are often used interchangeably, but there is a clinical distinction. "Frown lines" can refer to lines anywhere on the upper face associated with expression, including horizontal forehead lines. The "11s" specifically refer to the vertical lines in the glabellar area between the brows, the two creases driven by the corrugator and procerus muscles. Treating the 11s involves a specific anatomical approach that differs from treating the horizontal lines of the frontalis muscle above them.
Can anti-wrinkle treatment make the 11s disappear completely?
This depends on whether the lines are dynamic or static. Dynamic 11s, those that appear only during expression and resolve at rest, respond well, and the resting face typically shows a significant reduction in line visibility. Static 11s, those present even when the face is relaxed, represent structural changes to the skin and may not resolve completely with anti-wrinkle treatment alone, though reducing ongoing muscle activity over time allows the skin to partially recover. The honest answer to what is achievable in your individual case is part of the initial consultation conversation.
How long does treatment for the 11s last?
For most people, the effect on glabellar muscle activity lasts between three and five months, with variation depending on individual metabolism, muscle density, and treatment history. Consistent treatment over multiple cycles tends to produce progressively longer-lasting results, as the muscles being used less frequently gradually reduce in activity. A review appointment at two weeks after treatment establishes the baseline for future sessions and allows any fine-tuning of placement or dose.
Does treating the 11s affect my ability to make facial expressions?
The goal at Core Aesthetics is to reduce the specific movement pattern driving the lines, not to eliminate expression in the glabellar area altogether. A conservative approach preserves the ability to show concentration or emotion naturally, while reducing the depth and frequency of the crease-forming contraction. Treatment is assessed individually; the amount of effect varies based on placement, dose, and the individual’s response. At the two-week review, any adjustment to preserve or modify the expression range is discussed.
At what age should I start considering treatment for the 11s?
There is no universally correct age. The relevant clinical question is the stage the lines are at, dynamic, early static, or established static, rather than the patient’s chronological age. Some people in their late twenties have progressed to early static 11s due to strong muscle activity or significant sun exposure; others in their forties still have predominantly dynamic lines. A consultation at Core Aesthetics is the appropriate way to assess which stage you are at and whether treatment is warranted, premature, or not needed at this time.
Does the procerus need to be treated separately from the corrugators?
Yes, in most cases. The procerus and corrugator supercilii have distinct positions, directions of pull, and movement patterns. Treating only the corrugators, for example, may soften the vertical crease but leave the horizontal procerus component unaddressed, or shift the balance of brow forces in an unintended way. Assessment maps the activity of both muscle groups individually, and the treatment approach addresses the glabellar complex as a whole rather than targeting a single muscle in isolation.
Can I come in for treatment without a prior consultation?
No. Under AHPRA’s September 2025 guidelines, registered practitioners must not administer a new prescription cosmetic treatment at the same appointment where it is first proposed. Core Aesthetics has always operated on a consultation-first model: every new patient attends a thorough assessment appointment before any treatment is recommended or scheduled. This structure supports better clinical decision-making and allows time for informed consent. Returning patients who are continuing an established treatment plan are assessed individually.