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Long-pulsed Nd:YAG: there is a trial with a sham-irradiation control

For keratosis pilaris, one arm was divided into upper and lower parts; one part had the laser and the other had sham irradiation. After four sessions at four-week intervals, instrument-measured skin roughness fell significantly (P < .001). Twenty-three people took part.

Last checked Sep 20, 2026

At a glance

Session length
15–30 min
Pain
Moderate
Downtime
0–1 days
Sessions
4 sessionsReported in a trialThe sham-controlled trial gave four treatments at four-week intervals.
How long it lasts
Not applicable
Relative cost
Lower
How well established
Moderate evidence

“Reported in a trial” means a number a study on this page actually reported. “Typical range” is not a measured value but roughly how it is usually done, and it varies by clinic and by person.

Cost is not an amount but a band: where this procedure falls when the ones on this site are lined up per session, or per area treated. Real prices differ several-fold by clinic and by how much is treated, so they are not given here. Surgery is measured on a different scale and cannot be compared with this band.

This is not how large the effect is but how well confirmed it is. It shows the highest grade among the findings on this page.

Korean classification Being checkedThe regulatory class has not yet been confirmed against a primary document. It will be filled in once it is.

The 1064 nm Nd:YAG laser has a long wavelength and reaches deep. In Korea it is used for pigment, vessels and hair removal; this page covers only the trials in keratosis pilaris.

Keratosis pilaris is the common, stubborn roughness on the outer arms and thighs — keratin plugging follicular openings with redness around them. Topical keratolytics such as urea and salicylic acid are first line, but it generally returns when you stop.

What makes this stand out on this site is the control group. Trials of device treatments usually compare against an untreated area; the trial below used the same device held the same way with the light switched off. It was designed to subtract what merely applying the device does.

What is established

Moderate evidence

Skin roughness fell below the sham-irradiated area

This is a 2020 trial at Chulalongkorn University, Thailand. 23 people with untreated keratosis pilaris on the upper outer arms took part.

The design is tight. One arm was divided into an upper and a lower part, and one part was randomised to the 1064 nm Nd:YAG laser while the other received sham irradiation. Four treatments at four-week intervals, with Antera3D measurements of roughness, erythema and pigmentation four weeks after the last session.

Results:

  • Roughness measured by Antera3D fell significantly below the control part (P < .001).
  • On the participants' Global Improvement Score, roughness, erythema, pigmentation and overall appearance all improved significantly (all P < .001).
  • Satisfaction scores were significantly better for the treated parts (P < .001).
  • No adverse events — burning, bullae, erosion, post-inflammatory pigment change or scarring — occurred in any subject throughout.

One thing has to be flagged. The paper's title says 'randomized, double-blind, sham-irradiation-controlled', while the methods say 'randomized, single-blind'. Those are not the same claim. The abstract does not settle which is correct, so we read it the weaker way (single-blind).

This matters because of the endpoints. Instrument-measured roughness is less swayed by who knew what, but the participants' own global improvement and satisfaction scores can tilt if they knew which part was treated.

And there were 23 people. A single small trial.

  • Randomised controlled trial in people · 23 participants · 16 weeks · Compared with vehicle (same formula minus the active) · Funding not declared · Endpoint instrument measurement PMID 31713266
Moderate evidence

It tied with 20% TCA

This is a 2022 trial at Cairo University, Egypt. 20 people had 20% trichloroacetic acid (TCA) compared against the long-pulsed 1064 nm Nd:YAG laser, assessed clinically and by dermoscopic score.

Investigator Global Assessment:

  • Laser-treated area: moderate improvement in 2 (10%), marked in 10 (50%), excellent in 8 (40%)
  • TCA-treated area: marked in 9 (45%), excellent in 11 (55%)

Dermoscopic scores fell significantly with both, and neither the global assessment nor the reduction in dermoscopic score differed between the two methods.

Before reading this as 'the laser is as good as TCA', see two things.

First, there were 20 people. Comparing two active treatments in 20 people and finding no difference may mean there is none, or that there was no power to find one.

Second, numerically TCA was slightly ahead — excellent improvement in 55% against 40%.

The practical difference lies elsewhere, though. 20% TCA is far cheaper and available anywhere. If there is a reason to choose the laser it is more likely about downtime or risk by skin type — and this trial did not make that comparison.

  • Randomised controlled trial in people · 20 participants · Compared with another active ingredient · Funding not declared · Endpoint scores from blinded assessors PMID 35917264

Known risks

  • The 2020 trial reported no burns, bullae, erosion, post-inflammatory pigment change or scarring at all. But that was 23 people, on arms only.
  • The general risks of a 1064 nm laser apply: transient erythema, swelling and pain. A rubber-band snap sensation during treatment is common.
  • The darker the skin, the higher the risk of pigment change. The trials above were run in Thailand and Egypt.
  • Keratosis pilaris generally returns when treatment stops. Neither trial looked beyond the end of treatment.
  • Say in advance if you take anything that causes photosensitivity.

What is not established

  • We found no trial measuring how long it lasts. The longest look was four weeks after the final session.
  • We found no randomised comparison against topical keratolytics. Whether to choose this over urea or salicylic acid cannot be answered here.
  • How many sessions is right is unsettled. The trial above used four.
  • Device settings are not given in detail in the abstracts. Even at 1064 nm, pulse width and fluence make it a different treatment.
  • Both trials enrolled around 20 people.

Whether to have it done is a decision to make with a doctor.

What this article relies on

  1. PubMed — 미국 국립의학도서관 문헌 데이터베이스National Library of Medicine · Checked on 2026-09-16