Smile lines: 11 lines, expression wrinkles, and what they reveal about your skin

Smile lines refer to the wrinkles that appear around the mouth and eyes when the face moves. Over time, these expression lines become more visible, especially the folds around the mouth and the so-called “11 lines” between the eyebrows. Some people notice them mainly in photos or in the mirror in the morning, when facial expressions from the day before are still faintly imprinted on the skin.

Contrary to common belief, these lines are not only linked to age. They also reflect how the face moves, skin quality, and lifestyle habits.

What are the 11 lines when I smile?

The “11 lines” are two vertical wrinkles that appear between the eyebrows. They are not directly caused by smiling, but they often become more noticeable on expressive faces.

Why are they called “11 lines”?

The name comes from their shape:

• Two parallel vertical lines
• Located between the eyebrows
• Resembling the number 11

In dermatology, they are also known as glabellar lines or frown lines.

How they form

These lines are mainly caused by repeated contraction of two muscles:

• The corrugator muscle (pulling the brows together)
• The procerus muscle (pulling the skin downward between the brows)

For example, someone who spends long hours in front of a screen, constantly concentrating or squinting, may notice these lines forming earlier.

Are they related to smiling?

Indirectly, yes. Facial expressions are interconnected: smiling, concentrating, or frowning all involve facial muscle activity. Over time, the skin “learns” these repeated movements.

What is the main cause of smile lines?

Smile lines do not have a single cause but rather a combination of factors.

Aging and collagen loss

This is the primary cause.

As we age:

• Collagen production decreases
• Skin loses elasticity
• Facial volume gradually diminishes

As a result, folds around the mouth and eyes become more visible even at rest.

Repeated facial expressions

Every smile, laugh, or facial movement creates temporary folds in the skin.

For example, someone who laughs frequently or is very expressive in conversation will often develop more pronounced nasolabial folds earlier than someone with a more neutral expression.

Sun exposure (a major but often overlooked factor)

UV rays accelerate skin aging.

They cause:

• Collagen breakdown
• Loss of firmness
• Deeper wrinkles over time

This is why some people notice visible smile lines as early as their 30s.

Lifestyle and environmental factors

Other contributors include:

• Smoking (reduces oxygen supply to the skin)
• Chronic stress (constant muscle tension)
• Lack of sleep
• Dehydration
• Pollution

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Une publication partagée par Dr. Simon Ourian | Cosmetic Dermatology Beverly Hills (@simonourianmd1)

What do smile lines say about a person?

Smile lines do not carry a single meaning. Their interpretation depends on their depth, visibility, and context.

A naturally expressive face

In many cases, smile lines simply reflect an expressive personality.

They are common in people who:

• Smile frequently
• Laugh often
• Use animated facial expressions when speaking

For example, two people of the same age may have very different smile lines simply because one is more expressive in daily life.

A sign of skin maturation

From a dermatological perspective, smile lines mainly indicate:

• Gradual loss of facial volume
• Reduced skin elasticity
• Natural aging of connective tissue

They are not a flaw, but a normal biological process.

A culturally interpreted feature

In some cultures, smile lines are associated with:

• Maturity
• Experience
• Emotional richness

In others, they may be perceived as a sign of fatigue or aging.

How do smile lines evolve over time?

Smile lines typically progress in stages.

Stage 1: dynamic fine lines

At first, they only appear when smiling or expressing emotions and disappear at rest.

Stage 2: semi-permanent wrinkles

Over time, they remain partially visible even when the face is relaxed.

Stage 3: established folds

At a later stage, they become deeper and visible all the time.

For example, by the age of 45, nasolabial folds may be noticeable even on a relaxed face.

Can smile lines be prevented?

They cannot be completely avoided, but their progression can be slowed.

Daily sun protection

Sunscreen is one of the most effective anti-aging tools.

It helps:

• Preserve collagen
• Reduce UV damage
• Slow premature wrinkling

Proper hydration

Well-hydrated skin looks plumper and shows fewer lines.

Key ingredients include:

• Hyaluronic acid
• Glycerin
• Ceramides

Lifestyle habits

Daily habits also play a major role:

• Getting enough sleep
• Avoiding smoking
• Staying hydrated
• Managing stress levels

How can you reduce smile lines naturally?

Effective skincare ingredients

Certain actives are widely used to improve skin texture:

• Retinol: boosts cell turnover
• Vitamin C: brightens and protects against oxidative stress
• Peptides: support collagen structure

For example, a simple routine combining vitamin C in the morning and retinol at night can gradually soften fine lines around the mouth and eyes.

Facial massage

Facial massage helps relax muscles and improve circulation.

It can:

• Temporarily smooth expression lines
• Reduce facial tension
• Improve overall skin appearance

Realistic expectations

Skincare does not erase smile lines completely, but it can:

• Soften their appearance
• Improve skin texture
• Create a more even complexion

What aesthetic treatments are available for smile lines?

Hyaluronic acid fillers

Fillers are used to restore volume in nasolabial folds.

Effects:

• Immediate visible improvement
• Restored facial volume
• Smoother appearance

Botox

Botox reduces muscle activity responsible for expression wrinkles.

It is commonly used for:

• Crow’s feet
• Dynamic forehead and glabellar lines

Laser and radiofrequency treatments

These techniques stimulate collagen production deep within the skin.

They help:

• Tighten skin
• Improve texture
• Gradually reduce fine lines

Should you try to eliminate smile lines completely?

A natural part of facial expression

Smile lines are not only a sign of aging. They also reflect:

• Emotions
• Expressions
• Life experience

A more realistic goal

In most cases, the goal is not to remove them entirely, but to:

• Soften their appearance
• Restore lost volume
• Maintain a natural look

Conclusion

Smile lines, including nasolabial folds and “11 lines” between the eyebrows, mainly develop due to repeated facial expressions, collagen loss, and external factors such as sun exposure. They are not simply a sign of age but also a reflection of how the face moves and lives over time.

While they cannot be fully prevented, their progression can be slowed and their depth reduced through skincare, lifestyle habits, and, when needed, aesthetic treatments. The most effective approach is not to erase facial expressions, but to maintain a balanced, natural-looking skin while softening the most pronounced lines.