Frown lines and forehead lines why they form, and what softens each type

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Frown lines and forehead lines: what they are

Frown lines, which doctors call glabellar lines, are the one, two or three vertical creases between the eyebrows. They are made by two small muscles, the corrugator, which pulls the brows together, and the procerus, which pulls the inner brows down. Frowning in concentration, squinting at a screen or into bright sunlight works these muscles many times a day.

Forehead lines are the horizontal lines across the forehead. They are made by the frontalis, the broad muscle that lifts the eyebrows. It is the only muscle that raises the brows, and people with heavy upper eyelids or low brows often use it constantly, without noticing, to keep their eyes open. That matters for treatment, as explained below.

Frown lines tend to make a relaxed face look stern, tired or worried in photos. Forehead lines tend to make a face look older or surprised. Many people have both, and a plan usually looks at the whole upper face rather than one crease.

Dynamic vs static

Dynamic lines and static lines: a simple mirror check

A dynamic line appears only when the muscle moves and disappears when the face relaxes. A static line stays visible at rest, because years of folding, sun damage and collagen loss have etched it into the dermis, the thick layer of skin that holds collagen. Most people in their thirties and forties have a mix: lines that are mostly dynamic with a faint static crease underneath.

This difference decides what helps. Relaxing a muscle works well on lines made by movement. It cannot fill a crease that is already etched, though with regular treatment the skin is folded less often and many static lines become shallower over time.

• Relax your face completely and look in a mirror in good daylight. Lines you can still see are static, or partly static.
• Frown hard, then relax. Lines that appear only with the frown are dynamic.
• Raise your brows, then relax. Watch whether your brows drop and your upper lids feel heavier as you relax; if so, your forehead muscle may be holding your brows up.
• Look closely at the skin between the lines. Fine crisscross creasing and thin, dry skin point to skin quality, which needs a different approach from muscle relaxation.

Causes

Why frown and forehead lines form

A pan-Asian consensus of plastic surgeons and dermatologists noted that indications and doses for wrinkle-relaxing treatment in Asian patients differ from those described for Caucasian patients, because of differences in facial shape, anatomy and aesthetic expectations. A doctor assesses how your own face moves before planning anything.

• Repeated muscle movement: every frown or brow raise folds the skin in the same place. Over the years the fold becomes a line.
• Sun and light: ultraviolet light breaks down collagen and elastin. In Singapore, UV levels are high all year, and squinting in bright light adds to the frowning.
• Collagen loss with age: the dermis thins and becomes less springy, so creases form sooner and stay longer.
• Heavy lids or low brows: people who lift their brows to see more clearly work the forehead muscle all day, which deepens forehead lines.
• Habits: long hours at screens, uncorrected eyesight, stress, smoking, poor sleep and dehydration can all make lines look deeper.
• Anatomy and genetics: muscle strength, brow shape and skin thickness vary between people and ethnic groups, which is one reason dosing and placement are individual.

Matching the treatment

Line type, what helps, and where

SkinRev Lab prices are per session, before GST. Medical treatments are performed by Dr Sin Yong at IN Eternity Clinic and priced at consultation by the clinic.

Wrinkle-relaxing injections

Wrinkle-relaxing injections for dynamic lines

Wrinkle-relaxing injections use a prescription neuromodulator to reduce the activity of specific facial muscles. In Singapore they are a medical treatment, given by a doctor after assessing how the face moves. Tiny amounts are placed into the frown muscles, the forehead muscle, or both. The effect starts within a few days, builds over about two weeks, and wears off gradually as the nerve endings recover, commonly after about three to four months, though this varies.

The evidence for frown lines is strong. A meta-analysis of seven placebo-controlled trials with 1,474 people found treatment far more effective than placebo, including for the appearance of frown lines at rest, with no significant difference in adverse events between the groups. For forehead lines, a 12-month phase 3 trial of 391 people treating the forehead and frown area together found that 61.4% improved by at least two grades on a wrinkle scale at day 30, compared with none on placebo.

Forehead treatment needs more care than frown treatment. Because the frontalis is the only brow-lifting muscle, relaxing too much of it can make the brows and upper lids feel heavy, and treating it unevenly can give a peaked or surprised brow. Modern practice uses lower, well-spread doses that soften lines while keeping natural movement, and often treats the frown muscles at the same visit so the brows stay balanced.

Etched lines

Fillers and skin boosters for lines that stay at rest

When a frown line stays visible at rest, a doctor may combine muscle relaxation with treatment for the skin itself. A global consensus of injectors described combining fillers with wrinkle-relaxing injections as a standard of care, using lower doses to modulate rather than freeze muscles, and planning around whole areas of the face rather than single lines.

Injectable skin boosters place tiny amounts of soft hyaluronic acid, polynucleotides or other materials into the skin to improve hydration, texture and fine lines. They do not add shape. For a single deep frown crease, some doctors use a very small amount of soft filler placed superficially, but this is a decision for an experienced injector only.

The frown area and forehead are among the higher-risk sites for filler. A review of published cases of vision loss after filler found the glabella involved in 27.1% and the forehead in 18.8% of 48 new cases, because arteries here connect with the circulation of the eye. This is why many doctors relax the muscles first, use the smallest effective amounts, and avoid filler where muscle treatment alone is enough.

SkinRev Lab · Non-invasive

SKINTIGHT and SKINLIFT: what they can and cannot do

SKINTIGHT is a microplasma resurfacing and tightening session on the Alma PrimeX. A pin-tip applicator forms fine micro-channels in the skin surface while warming the dermis, prompting collagen renewal over the following weeks. On the forehead and between the brows it is used for crepey texture and fine static lines. Mild redness for a few hours is usual at tightening settings; deeper settings can leave pinpoint scabbing for a few days. It is S$588 per zone, before GST.

SKINLIFT is a needle-free focused ultrasound protocol aimed at the deeper support layers of the face. Its mapped zones include the eye area, where it is used for heavy upper lids and mild laxity around the brow, which can reduce the urge to lift the brows to see. SKINLIFT Face is S$888 per session, before GST, and eye-area work is assessed and quoted by your Aesthetic Specialist. Change builds gradually over a course.

Neither treatment relaxes the frown or forehead muscles, so neither will stop a line that forms every time you frown. They suit people whose concern is mainly skin quality or mild upper-face laxity, or who want a needle-free step alongside medical care. Dr Sin Yong, SkinRev Lab's Medical Adviser, trains the team hands-on on these machines.

Prevention

Slowing frown and forehead lines down

• Wear broad-spectrum sunscreen every day on the forehead, and reapply when outdoors. In a four-and-a-half-year randomised trial, adults who used sunscreen daily showed no detectable increase in skin ageing, and 24% less ageing than those using it when they chose.
• Wear sunglasses outdoors so you squint and frown less in bright light.
• Get your eyesight checked if you find yourself frowning at screens; uncorrected vision is a common hidden driver.
• Use a retinoid or other evidence-based skincare at night, introduced slowly to avoid irritation.
• Keep the skin hydrated; dehydration makes fine lines look deeper.
• If lines are starting to stay at rest, earlier, lighter muscle treatment under a doctor can slow them deepening. More is not better.

Safety

Side effects, and who should wait

After wrinkle-relaxing injections, small bumps for 15 to 30 minutes, mild headache and pinpoint bruising are the usual effects. Less often, the brow or upper lid can droop for a few weeks, or the brows can look uneven; these settle as the effect wears off. After filler or boosters, swelling, tenderness and bruising are common for a few days.

Wrinkle-relaxing injections are not given during pregnancy or breastfeeding, in people with neuromuscular conditions such as myasthenia gravis, or over infected skin. Tell the doctor about all medicines and previous eyelid surgery. After any filler, skin turning pale, white, blotchy or dusky, increasing pain, or any change in vision is an emergency: contact the clinic at once or go to an emergency department.

Where to go

Frown and forehead line treatment in our network

Wrinkle-relaxing injections, fillers and injectable skin boosters are performed by Dr Sin Yong at IN Eternity Clinic, 9 Scotts Road, #12-01 Pacific Plaza, beside Orchard MRT, after he has assessed how your face moves and where your brows sit. They are priced at consultation by the clinic; WhatsApp +65 8815 3008.

SKINTIGHT and SKINLIFT are at SkinRev Lab, #B1-28 CityLink Mall, on the underground link between City Hall and Esplanade MRT. If your lines are mainly made by muscle movement, your Aesthetic Specialist will say so and can pass your enquiry to IN Eternity Clinic. Results vary between people.

Sources

References & sources

1. Guo Y, Lu Y, Liu T, et al. Efficacy and safety of botulinum toxin type A in the treatment of glabellar lines: a meta-analysis of randomized, placebo-controlled, double-blind trials. Plast Reconstr Surg. 2015;136(3):310e-318e.
2. Fagien S, Cohen JL, Coleman W, et al. Forehead line treatment with onabotulinumtoxinA in subjects with forehead and glabellar facial rhytids: a phase 3 study. Dermatol Surg. 2017;43 Suppl 3:S274-S284.
3. Sundaram H, Huang PH, Hsu NJ, et al. Aesthetic applications of botulinum toxin A in Asians: an international, multidisciplinary, pan-Asian consensus. Plast Reconstr Surg Glob Open. 2016;4(12):e872.
4. Sundaram H, Liew S, Signorini M, et al. Global Aesthetics Consensus: hyaluronic acid fillers and botulinum toxin type A, recommendations for combined treatment and optimizing outcomes in diverse patient populations. Plast Reconstr Surg. 2016;137(5):1410-1423.
5. Beleznay K, Carruthers JDA, Humphrey S, Carruthers A, Jones D. Update on avoiding and treating blindness from fillers: a recent review of the world literature. Aesthet Surg J. 2019;39(6):662-674.
6. Hughes MC, Williams GM, Baker P, Green AC. Sunscreen and prevention of skin aging: a randomized trial. Ann Intern Med. 2013;158(11):781-790.

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