What is the difference between dynamic and static wrinkles?

A dynamic line appears when a muscle contracts and disappears when it relaxes. A static line is visible when your face is still, because the skin has been creased repeatedly and has changed. Toxin relaxes the muscle, so it answers the first. The second needs the skin itself to change, or the crease to be filled.

How effective is botulinum toxin really?

Unusually so, by the standards of this field. A GRADE-assessed meta-analysis of three Phase III randomised trials and 704 participants found relative risks at day 30 of 21.49 for at least one grade of improvement in glabellar lines, 19.17 for forehead lines and 11.68 for lateral canthal lines, all against placebo. Serious adverse events were not more frequent than placebo.

Do creams actually work on wrinkles?

One does, with randomised evidence. A meta-analysis of eight trials and 1,361 patients found topical tretinoin significantly improved fine wrinkles (MD 0.412; 95% CI 0.233–0.590) and coarse wrinkles (MD 0.245; 95% CI 0.119–0.370) against vehicle. Those are modest numbers, and they are real, sustained, and cheap.

Will an energy device get rid of my lines?

Not directly. Focused ultrasound and radiofrequency tighten tissue that has become slack; they do not erase a crease made by movement or fill a fold made by lost volume. If a device is proposed for a specific line, ask what mechanism is supposed to remove it.

What if my "wrinkle" is actually a fold?

Then no wrinkle treatment addresses it. A nasolabial fold or a marionette line is often a volume and descent problem, and treating it with toxin or a resurfacing course spends money on the wrong mechanism. Ask the clinic to say which it is before agreeing a plan.

Can wrinkles be prevented?

Partly, and there is a randomised trial rather than a marketing claim behind it. Over 4.5 years, 903 adults were randomised to daily or discretionary sunscreen: the daily group showed no detectable increase in skin aging, and 24% less aging than the discretionary group. Nothing else in this field has that kind of evidence.

Concerns · also called fine lines, 주름, expression lines

Wrinkles: which lines move, which lines stay, and what each one answers to

Toxin works on movement lines, tretinoin on photodamage, and daily sunscreen stopped detectable aging over 4.5 years. Different lines need different tools.

Author: Aesthetics Korea Editorial Team
Medical review: Reviewed by 2 doctorsSee methodology
Published: 8 September 2026
Last updated: 8 September 2026
Last reviewed: —6 min read

Short answer

The useful split is between lines that appear when you move and lines that are there when your face is still. Botulinum toxin has the largest effect size of anything on this site for movement lines — pooled across three trials, patients were around twenty times more likely to improve than on placebo. Static lines from sun damage answer to topical tretinoin, modestly but reliably, and daily sunscreen is the only intervention shown over years to stop the process.

Key facts

Two kinds of line: Dynamic lines appear on movement; static lines are visible at rest
Movement lines: Botulinum toxin — RR 21.49 for at least one grade of improvement in glabellar lines
Photodamage lines: Topical tretinoin improved fine wrinkles (MD 0.412) and coarse wrinkles (MD 0.245)
Laxity, not lines: Focused ultrasound and radiofrequency tighten; they do not erase a crease
Volume loss: A fold caused by lost volume is a filler question, not a wrinkle question
Prevention: Daily sunscreen — no detectable increase in skin aging over 4.5 years in a randomised trial

Which lines are you actually looking at

Stand in front of a mirror and stop moving your face.

The lines that disappear are dynamic — made by muscle. The lines still there are static — the skin itself has changed. And some of what people call wrinkles is neither: a fold produced by lost volume or descended tissue, which no wrinkle treatment touches.

Three different mechanisms. Three different answers. Getting this wrong is the reason people report that a treatment "didn't work" when in fact it was never aimed at their problem.

Movement lines: the strongest evidence on this site

Botulinum toxin relaxes the muscle that folds the skin, and the effect sizes are larger than anything else covered here.

A GRADE-assessed meta-analysis of three Phase III randomised trials and 704 participants found, at day 30 against placebo, relative risk of at least one grade of improvement of:

21.49 for glabellar frown lines (95% CI 9.89–46.73)
19.17 for horizontal forehead lines (9.23–39.80)
11.68 for lateral canthal lines (7.49–18.20)

All at p < 0.00001, with a Global Aesthetic Improvement Scale difference of 2.29 points. Serious adverse events were not more frequent than on placebo.

For context: most treatments discussed on this site produce modest differences in a wide confidence interval. This one produces a twenty-fold difference in the odds of visible improvement. When someone says "the science on aesthetics is thin", this is the exception.

Two honest notes. The evidence is for upper facial lines, which is where the trials were run — not for every use a clinic will suggest. And the ≥2-grade figures, though enormous, carry confidence intervals wide enough to read as "far better than placebo" rather than as a number.

Static lines: the cheap option with real trials

A line that stays at rest needs the skin to change, and the best-evidenced way to do that is a prescription cream.

A meta-analysis of eight randomised trials and 1,361 patients found topical tretinoin significantly improved:

Fine wrinkles — MD 0.412 (95% CI 0.233–0.590)
Coarse wrinkles — MD 0.245 (95% CI 0.119–0.370)

Read those honestly: they are modest. Tretinoin is not going to do what an image on a clinic wall implies. But the effect is real, randomised, sustained over follow-ups from 16 weeks to two years, and costs a fraction of any procedure.

The resurfacing treatments covered elsewhere on this site — fractional laser, microneedle radiofrequency — work on the same problem by a different route, and belong in the conversation. What should not happen is a procedure course proposed with no topical plan attached.

What tightening devices do, and do not

Focused ultrasound and radiofrequency tighten tissue that has become slack. The pooled evidence for focused ultrasound is strong on that measure — 89% investigator-rated improvement across 42 studies.

They do not erase a crease made by repeated movement, and they do not replace lost volume. If a device is proposed for one specific line, ask what mechanism is supposed to remove it. The answer should be more specific than "it tightens".

When it is a fold, not a wrinkle

A nasolabial fold, a marionette line, a hollow under the eye — these are frequently sold as wrinkle treatments and frequently are not.

If the cause is volume loss, that is a filler or collagen-stimulator question. If the cause is descent, it belongs with sagging. Toxin and resurfacing will not resolve either, and a clinic proposing them for a fold is either misreading the face or selling what it has.

The one thing that prevents them

Nothing else in this field has evidence like this, and it costs nothing at a clinic.

Over 4.5 years, 903 adults were randomised to daily or discretionary sunscreen use, with photoaging graded by blinded assessors. The daily sunscreen group showed no detectable increase in skin aging, and 24% less aging than the discretionary group (relative odds 0.76; 95% CI 0.59–0.98).

The same trial found β-carotene supplementation had no overall effect — which is worth remembering the next time an oral "skin" supplement is added to a treatment package.

What to ask at a consultation

Is this line dynamic, static, or a fold? Get the answer before the plan.
If toxin — which product, in Korean, and how many units where?
If resurfacing — what topical am I on afterwards, and for how long?
If a device is proposed for a specific line, what is the mechanism?
What should I expect at four weeks, and when should I judge it?

The bottom line

Separate the lines that move from the lines that stay, and both from folds caused by volume loss. Botulinum toxin has the largest effect size on this site for movement lines — around twenty times the odds of improvement against placebo across 704 patients. Static photodamage lines respond modestly but reliably to topical tretinoin across 1,361 patients. Tightening devices address laxity, not creases. And daily sunscreen is the only intervention here shown across 4.5 years to stop the process rather than treat its results.

Frequently asked questions

What is the difference between dynamic and static wrinkles?: A dynamic line appears when a muscle contracts and disappears when it relaxes. A static line is visible when your face is still, because the skin has been creased repeatedly and has changed. Toxin relaxes the muscle, so it answers the first. The second needs the skin itself to change, or the crease to be filled.
How effective is botulinum toxin really?: Unusually so, by the standards of this field. A GRADE-assessed meta-analysis of three Phase III randomised trials and 704 participants found relative risks at day 30 of 21.49 for at least one grade of improvement in glabellar lines, 19.17 for forehead lines and 11.68 for lateral canthal lines, all against placebo. Serious adverse events were not more frequent than placebo.
Do creams actually work on wrinkles?: One does, with randomised evidence. A meta-analysis of eight trials and 1,361 patients found topical tretinoin significantly improved fine wrinkles (MD 0.412; 95% CI 0.233–0.590) and coarse wrinkles (MD 0.245; 95% CI 0.119–0.370) against vehicle. Those are modest numbers, and they are real, sustained, and cheap.
Will an energy device get rid of my lines?: Not directly. Focused ultrasound and radiofrequency tighten tissue that has become slack; they do not erase a crease made by movement or fill a fold made by lost volume. If a device is proposed for a specific line, ask what mechanism is supposed to remove it.
What if my "wrinkle" is actually a fold?: Then no wrinkle treatment addresses it. A nasolabial fold or a marionette line is often a volume and descent problem, and treating it with toxin or a resurfacing course spends money on the wrong mechanism. Ask the clinic to say which it is before agreeing a plan.
Can wrinkles be prevented?: Partly, and there is a randomised trial rather than a marketing claim behind it. Over 4.5 years, 903 adults were randomised to daily or discretionary sunscreen: the daily group showed no detectable increase in skin aging, and 24% less aging than the discretionary group. Nothing else in this field has that kind of evidence.

Medical evidence

Systematic review2026n = 704
Efficacy and Safety of IncobotulinumtoxinA for the Simultaneous Treatment of Upper Facial Lines: A GRADE Assessed Systematic Review and Meta-analysis
"IncobotulinumtoxinA provides consistent and clinically meaningful improvements in wrinkle severity across all upper facial regions compared with placebo." At day 30, relative risk of at least one grade of improvement was 21.49 (glabellar), 19.17 (forehead) and 11.68 (lateral canthal), all p < 0.00001.
Systematic review2025n = 1361
Tretinoin for Photodamaged Facial Skin: Systematic Review and Meta-Analysis of Randomized Controlled Trials
"Topical tretinoin is a safe and effective treatment for fine and coarse facial wrinkles resulting from photodamage." Fine wrinkles MD 0.412 (95% CI 0.233–0.590); coarse wrinkles MD 0.245 (95% CI 0.119–0.370).
Randomised trial2013n = 903
Sunscreen and prevention of skin aging: a randomized trial
"Regular sunscreen use retards skin aging in healthy, middle-aged men and women." The daily sunscreen group showed no detectable increase in skin aging after 4.5 years; 24% less aging than discretionary use (relative odds 0.76; 95% CI 0.59–0.98).

Sources

Listed in the order they are used. Source class follows the methodology.

1.Efficacy and Safety of IncobotulinumtoxinA for the Simultaneous Treatment of Upper Facial Lines: A GRADE Assessed Systematic Review and Meta-analysis, Aesthetic Surgery Journal Open Forum, 2026Peer-reviewed researchaccessed 2026-09-08Three Phase III randomised trials, 704 participants, mean age 44.8–47.8, 79.9–89.5% women. At day 30, relative risk of at least one grade of improvement: glabellar 21.49 (95% CI 9.89–46.73), forehead 19.17 (9.23–39.80), lateral canthal 11.68 (7.49–18.20). For at least two grades: 94.54, 115.04 and 76.26 respectively, with very wide confidence intervals. Global Aesthetic Improvement Scale mean difference 2.29 points. Serious adverse events lower than placebo (RR 0.14, p = 0.03); any adverse events and headache not significantly different.
2.Tretinoin for Photodamaged Facial Skin: Systematic Review and Meta-Analysis of Randomized Controlled Trials, Dermatology Practical & Conceptual, 2025Peer-reviewed researchaccessed 2026-09-08Eight randomised trials, 1,361 patients, median age range 29–76, follow-up 16 weeks to 2 years. Against vehicle, tretinoin significantly improved fine wrinkles (MD 0.412; 95% CI 0.233–0.590; p < 0.001) and coarse wrinkles (MD 0.245; 95% CI 0.119–0.370; p < 0.001). Sensitivity analyses confirmed robustness.
3.Sunscreen and prevention of skin aging: a randomized trial, Annals of Internal Medicine, 2013Peer-reviewed researchaccessed 2026-09-08903 adults under 55 in Nambour, Queensland, randomised to daily or discretionary sunscreen and to β-carotene or placebo, graded by blinded assessors over 4.5 years. Daily sunscreen group showed no detectable increase in skin aging; 24% less aging than discretionary use (relative odds 0.76; 95% CI 0.59–0.98). β-carotene had no overall effect.
4.Microfocused Ultrasound With Visualization (MFU-V) Effectiveness and Safety: A Systematic Review and Meta-Analysis, Aesthetic Surgery Journal, November 2024Peer-reviewed researchaccessed 2026-09-0842 studies. Investigator-assessed global aesthetic improvement 89%, patient-reported 84%. Cited here for what tightening devices do — improve laxity — rather than for removing an individual line.
5.의약품안전나라 (Drug Safety Korea), Ministry of Food and Drug SafetyGovernment / public bodyaccessed 2026-09-08Where a botulinum toxin product licensed in South Korea appears under its Korean product name. Several domestic toxins are sold here beyond the international brands.

Treatments

Concerns it addresses

Sagging skin: tightening, repositioning, and telling them apart

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