Skin Care Education

Frown Lines

Vertical creases between the eyebrows caused by repeated contraction of the glabellar muscles. Also referred to as glabellar lines or the 11 lines. One of the most consistently noticed expression lines on the face.

What Are Frown Lines?

Frown lines are the vertical creases that develop between the eyebrows, in the area of the face known as the glabella. They are formed by the repeated contraction of the corrugator supercilii and procerus muscles, which draw the brows inward and downward during frowning, concentrating, squinting, and other expressions that involve bringing the brows together. The colloquial term 11 lines comes from the appearance of two parallel vertical creases that the lines typically create when both sides are equally developed.

Like other expression lines, frown lines begin as dynamic creases that are visible only when the relevant muscles are actively contracting and resolve when the face returns to rest. Over time, as the skin’s structural proteins decline and its resilience decreases, these dynamic lines transition to static lines that remain visible even when the face is completely relaxed. It is at this static stage that they become most noticeable and most often a cosmetic concern.

What distinguishes frown lines from many other expression lines is the specific unintended resting expression they create. Because the vertical creases between the brows are visually associated with the expression of negative emotion, including anger, worry, or sternness, even a relaxed face with established frown lines can be perceived as conveying a tense or unfriendly expression. This disconnect between how a person actually feels and how their resting face reads is one of the most consistently reported motivations for addressing this area.

Types

Dynamic frown lines: vertical creases between the brows that are visible only when the corrugator supercilii and procerus muscles are actively contracting, such as during frowning or concentrating. Resolve completely when the face is at rest, indicating the skin retains sufficient elasticity to fully recover from the muscle contraction.
Static frown lines: vertical creases that remain visible between the brows even when the face is completely relaxed. Indicate that the crease has become a more permanent structural feature of the skin surface as a result of cumulative muscle movement and declining skin elasticity.

Causes and Contributing Factors

Factor	Description
Corrugator and procerus muscle activity	The primary cause. The corrugator supercilii draws the brows together and downward, and the procerus pulls the skin of the glabella downward. Every frown, squint, or expression of concentration involves these muscles contracting. The cumulative effect of thousands of daily contractions over many years is the progressive etching of vertical creases into the overlying skin.
Habitual concentration and screen use	Many people habitually contract the glabellar muscles during periods of concentration, reading, or screen use, often without awareness of doing so. Prolonged daily periods of this habitual contraction represent a substantial additional volume of muscle activity beyond normal facial expression, accelerating the development of permanent frown lines.
Squinting in bright light	Squinting involves contraction of the muscles around the eye as well as the glabellar muscles. People who spend significant time in bright light without adequate eye protection tend to squint more frequently, contributing to the cumulative muscle activity that drives glabellar line formation.
Loss of skin elasticity	As collagen and elastin decline with age, the skin between the brows becomes progressively less able to return to a fully smooth state after each muscle contraction. This is the mechanism by which dynamic frown lines transition to static lines that are visible at rest.
UV exposure	Cumulative UV exposure to the glabellar skin accelerates the structural protein breakdown that reduces the skin’s resilience and hastens the transition from dynamic to static lines. Sun-damaged skin loses its elasticity earlier and more severely than protected skin.
Genetics	The natural strength and activity level of the corrugator and procerus muscles, the thickness and structural quality of the glabellar skin, and the individual rate of skin ageing in this area are all significantly influenced by genetics.
Stress and negative emotional states	Chronic stress, anxiety, and habitual negative emotional states are associated with increased frequency and intensity of glabellar muscle contraction. The frowning and brow-furrowing expressions associated with these states contribute directly to the cumulative muscle activity that drives frown line development.

Frequently Asked Questions: Frown Lines

Frown lines and glabellar lines are two terms for exactly the same thing. Frown lines is the consumer-friendly common term used in everyday conversation and in most aesthetic contexts. Glabellar lines is the clinical anatomical term that refers to the same vertical creases between the eyebrows. Glabella is the anatomical name for the area of skin between the eyebrows and above the nose. The two terms are completely interchangeable.

Because the shape created by vertical creases running inward and downward between the brows is the same shape associated with expressions of negative emotion, including anger, worry, sternness, and displeasure. The brain reads facial shapes and configurations as emotional signals, and the downward-inward convergence of the glabellar creases mimics the brow configuration of negative expression even when no expression is being made. This is why people with established static frown lines are sometimes perceived as looking upset or stern even when they feel and intend to look neutral.

Yes. Frown lines and forehead lines are distinct expression lines caused by different muscles and running in different directions. Frown lines are the vertical creases between the eyebrows, produced by the corrugator supercilii and procerus muscles drawing the brows inward and downward. Forehead lines are the horizontal creases across the forehead, produced by the frontalis muscle raising the brows. Both are expression lines of the upper face but they involve different movements, affect different areas, and create distinctly different visual effects.

Yes. While static frown lines, visible at rest, are most commonly associated with the 30s and 40s onward, dynamic frown lines can be visible from early adulthood in individuals with naturally strong or very active glabellar muscles. People who spend long periods concentrating, who habitually furrow their brows, or who have significant UV exposure may develop noticeably deep dynamic lines in their 20s. With continued muscle activity and declining skin elasticity, these can transition to static lines relatively early in individuals with these characteristics.