Effectiveness and safety of 50ns versus 5ns Qs Nd:YAG 532nm laser in facial lentigines treatment

A comparison of different pulse duration of Q-switched Nd:YAG for the treatment of facial lentigines

Status

Active, not recruiting

Phases

Phase 4

Study type

Interventional

Source

TCTR

Registry ID

TCTR20210421003

Enrollment

Registered

2021-04-21

Start date

2014-05-01

Completion date

Unknown

Last updated

2026-08-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Facial lentigines lentigines, comparison, pulse duration, laser, Q-switched, 532nm

Interventions

Lentigines on one side of the face of patients were randomized to be treated with 50ns Qs Nd:YAG 532nm laser (experiment). Another side lentigines were treated with 5ns Qs Nd:YAG 532nm laser (active c

Experimental Device,Active Comparator Device

50 nanosecond(ns) Q-switched(Qs) Nd:YAG laser,5 nanosecond(ns) Q-switched(Qs) Nd:YAG laser

Eligibility

Sex/Gender

All

Age

18 Years to 80 Years

Inclusion criteria

Inclusion criteria: 1. Age between 18-80 years old 2. Facial lentigines on both sides of the face 3. Fitzpatrick skin phototype 3-5 4. Can follow the study protocol

Exclusion criteria

Exclusion criteria: 1. Photosensitive dermatosis, acne, skin infection or inflammation at the study area 2. Regular smoking 3. Pregnancy, within 3 months after child delivery, lactating women 4. Cannot follow the study protocol 5. History of allergy to local anesthesia (lidocaine or prilocaine), cannot tolerate cold air cooling 6. No written consent in the study participation 7. Conditions that investigators consider that may have some risks in participating the study such as keloids, psychiatric illness such as major depression or schizophrenia 8. Intense sun exposure 1 week before the study and cannot avoid sun exposure for 1 week after treatment 9. Do not allow to take facial photographs

Design outcomes

Primary

Measure	Time frame
Efficacy 1-week, 2-week, 3-week, 4-week, 8-week, 12-week, and 24-week after treatment Physician evaluation,efficacy Baseline, 1-week, 2-week, 3-week, 4-week, 8-week, 12-week, and 24-week after treatment Mexameter (color measurement: erythema and melanin indexes),Efficacy 4-week, 8-week, 12-week, and 24-week after treatment Patient evaluation	—

Secondary

Measure	Time frame
Adverse effects Immediate after treatment, 1-week, 2-week, 3-week, 4-week, 8-week, 12-week, and 24-week after treatment Physician evaluation	—

Countries

Thailand

Contacts

Public ContactSasima Eimpunth

Faculty of Medicine Siriraj Hospital

doctorsasima@gmail.com024194333

Outcome results

None listed

Source: TCTR (via WHO ICTRP) · Data processed: Aug 9, 2026