Glabellar lines are the vertical creases that form between your eyebrows, often called “frown lines” or “elevens” because they typically appear as two parallel vertical furrows. They’re caused by repeated contraction of the small muscles between your brows and, over time, by the skin’s declining ability to bounce back from those contractions.
What Causes Glabellar Lines
The main culprit is a pair of muscles called the corrugator supercilii, which sit just above each eye near the bridge of your nose. When you frown, concentrate, or squint, these muscles pull your brows inward and downward, bunching the skin between them into vertical folds. A second muscle, the procerus, runs vertically along the bridge of the nose and creates horizontal creases at the top of the nose when it contracts. Together, these muscles form what’s known as the glabellar complex.
In younger skin, the lines disappear the moment you relax your face. But facial muscles are unusual: unlike most muscles in the body, they attach directly into the skin rather than to bone on both ends. Every contraction tugs on the skin itself. Over thousands of repetitions a day, across years, these muscles essentially crease the skin along the same fold lines until the wrinkles become permanent.
The other half of the equation is what’s happening inside the skin. The middle layer of skin (the dermis) is built from collagen for strength, elastin for snap-back, and sugar-based molecules that hold water. With age, collagen breaks down faster than the body replaces it, the elastic fiber network disintegrates, and the skin loses hydration. The result is thinner, less resilient skin that can no longer resist the constant pulling of the muscles underneath. Researchers describe this as “dynamic discord”: the muscles keep contracting with the same force, but the skin above them progressively fails to recover.
Dynamic vs. Static Lines
Dermatologists classify glabellar lines by when they’re visible. Dynamic lines appear only during facial movement, when you’re actively frowning or squinting. Static lines are visible even when your face is completely relaxed. Most people start with dynamic lines, which gradually become static as the skin loses elasticity and the repeated folding leaves a permanent crease.
Clinicians grade severity on a four-point scale: none/minimal, mild, moderate, and severe. At the mild end, you might notice faint lines only in certain lighting. Severe glabellar lines involve deep, etched furrows visible at rest, sometimes with a depressed scar-like quality where the skin has thinned along the crease. This distinction matters because it determines which treatments are realistic. A deep, static line that’s been present for years won’t respond the same way as a newer dynamic crease.
Who Gets Them and When
Almost everyone develops some degree of glabellar lines with age, but several factors accelerate the process. People who are naturally expressive with their brows, who squint frequently (from uncorrected vision or bright sunlight), or who spend long hours concentrating at a screen tend to develop them earlier. Sun exposure speeds up the breakdown of collagen and elastin, making the skin more vulnerable to creasing. Smoking has a similar effect. Genetics also play a role in skin thickness and how quickly collagen degrades.
Dynamic glabellar lines can appear as early as the mid-20s. Static lines at rest typically become noticeable in the mid-30s to 40s, though this varies widely.
Neurotoxin Injections
The most common treatment for glabellar lines is a neurotoxin injection, widely known by the brand name Botox. The FDA-approved indication is specifically for moderate to severe glabellar lines associated with corrugator and procerus muscle activity. The standard protocol involves five small injections: two in each corrugator muscle and one in the procerus, totaling 20 units.
The injections work by temporarily blocking the nerve signals that tell those muscles to contract. With the muscles relaxed, dynamic lines disappear and static lines soften over time as the skin is no longer being repeatedly folded. Results typically appear within a few days and last three to four months before the muscle activity gradually returns. Multiple neurotoxin products are now FDA-approved for this purpose, though their dosing units are not interchangeable since each is measured using a different assay.
Topical Treatments
Topical products containing retinoids and peptides are widely marketed for frown lines, but the evidence for dramatic improvement in glabellar lines specifically is limited. One clinical study tested a serum containing a retinoid derivative and a 9.5% peptide blend applied twice daily for 16 weeks. While participants saw improvements in several signs of facial aging, the change in glabellar lines was not statistically significant. The mean improvement was essentially zero.
This makes sense given how these lines form. Topical products can improve skin texture, hydration, and fine surface wrinkles, but they can’t stop the underlying muscle from contracting. Retinoids do stimulate collagen production over months of use, which can help skin resilience in general, but they’re unlikely to erase an established frown line on their own. They’re most useful as a long-term maintenance strategy alongside other treatments, or for people with very early, superficial lines.
Dermal Fillers and Their Risks
For deep static lines that persist even after neurotoxin treatment, some providers use injectable fillers (typically hyaluronic acid) to physically fill the crease from below. However, the glabella is considered one of the most dangerous areas on the face for filler injections. The arteries that supply blood to the forehead and eyes run extremely close to the surface in this region, sometimes as little as 1.8 millimeters below the skin. In roughly 41% of people, these arteries sit directly underneath the glabellar crease lines themselves.
If filler material enters or compresses one of these arteries, the consequences can be severe: tissue death in the overlying skin, and in worst-case scenarios, blindness from filler particles traveling backward into the blood supply of the eye. The glabella has no backup blood supply from neighboring vessels, so a blockage here can’t be compensated for the way it might in other parts of the face. Even techniques designed to reduce risk, such as blunt-tipped needles and aspiration before injection, are not considered absolutely safe in this area. Deep, scarred glabellar lines are particularly risky because scar tissue can anchor blood vessels in place, preventing them from sliding away from the needle.
Surgical Options for Deep Lines
For people with deeply etched glabellar lines who want a longer-lasting solution, surgical approaches can address the problem at its source by weakening or cutting the muscles responsible. An endoscopic forehead lift involves small incisions behind the hairline, through which the corrugator and procerus muscles are partially cut. This permanently reduces the muscle’s ability to create the frown crease.
A less extensive option is glabellar myoplasty, which can be performed through an upper eyelid incision during blepharoplasty (eyelid surgery). The surgeon works through the inner corner of the eyelid to reach the glabellar muscles and sever them with cautery. This approach is sometimes chosen by people who are happy with their brow position but want the vertical frown lines addressed permanently. These are real surgical procedures with recovery time and risks, so they’re typically reserved for deep, well-established lines that don’t respond adequately to injections.