Lasers have become essential tools in dermatology, delivering precise, effective treatments for acne scars, pigmentation, hair removal, and skin rejuvenation.
With rapid advances in fractional, picosecond, and non-ablative technologies, clinicians must stay current on best practices and safety guidelines. This FAQ highlights the top trending questions about lasers in dermatology, offering concise, evidence-based insights to help dermatologists make informed clinical decisions.
1. Which lasers work best for atrophic acne scars, and how many sessions are typically needed?
Fractional resurfacing remains first line for atrophic acne scarring. Ablative fractional CO₂ and Er:YAG deliver greater scar improvement than non-ablative devices, but with more downtime; non-ablative 1540/1550-nm options offer modest gains with lower risk and faster recovery.1,2 Typical regimens involve 3 to 5 sessions spaced 4 to 8 weeks apart, with continued remodeling for 3 to 6 months. Combining fractional lasers with other modalities, such as microneedling, chemical peels, or adjuvant topical agents, can enhance outcomes in selected patients.1,2 Careful parameter selection and strict photoprotection are critical to minimize post inflammatory hyperpigmentation (PIH), especially in higher Fitzpatrick skin types.1
2. Is laser hair removal safe and effective in darker skin tones (Fitzpatrick IV–VI), and which device is preferred?
Yes, with appropriate technique. Long-pulsed 1064-nm Nd:YAG is preferred in darker skin because its deeper penetration and lower melanin absorption reduce epidermal injury and dyschromia.3 Contemporary Nd:YAG platforms demonstrate durable hair reduction with favorable safety when using longer pulse durations, appropriate fluences, epidermal cooling, and avoidance of tanned skin.3,4 Expect multiple sessions (often 6–8+) for maintenance-level reduction; counsel on PIH risk and the need for peri-treatment photoprotection.3,4
3. Do picosecond lasers clear tattoos faster or better than nanosecond Q-switched devices?
Head-to-head clinical data indicate picosecond platforms can achieve superior clearance with similar or fewer sessions vs nanosecond Q-switched lasers, particularly for recalcitrant and multicolored tattoos.5 Contemporary reviews emphasize device/wavelength selection (532/755/1064 nm), spot size, fluence, and ink/skin characteristics; adjunct strategies, such as perfluorodecalin patches and staged passes, may improve efficiency while maintaining safety.6 As with any protocol, spacing sessions to allow particle clearance and dermal recovery helps limit adverse effects.5,6
4. Can I perform laser procedures in patients taking or recently off isotretinoin?
A systematic review and multispecialty consensus found insufficient evidence to delay most cutaneous procedures, including fractional ablative and non-ablative lasers and laser hair removal, in patients currently on or recently off isotretinoin.7 Expert consensus supports proceeding with these procedures using prudent technique; mechanical dermabrasion and fully ablative laser resurfacing remain exceptions and are not recommended during isotretinoin therapy.7,8 Discuss risks; obtain informed consent; and individualize by procedure intensity, anatomic site, and patient risk factors.8
5. Where do lasers fit in melasma care?
Lasers are adjunctive, not primary, therapy for melasma. Systematic reviews show lasers and laser-combination approaches can reduce Melasma Area and Severity Index scores, but recurrence and PIH remain concerns, especially in higher phototypes.9,10 Reserve devices such as low-fluence QS-Nd:YAG or fractional non-ablative platforms for refractory cases after rigorous photoprotection and optimized topicals, such as hydroquinone-based regimens, and consider combination strategies with tranexamic acid.9,10 Set expectations for incremental benefit and the need for maintenance.9,10
References
- Utley C, Gold M. Treating acne scars in 2020: use of lasers. Dermatol Rev. 2021;2:4-10. doi:10.1002/der2.35
- Liu F, Zhou Q, Tao, M, Shu L, Cao Y. Efficacy and safety of CO₂ fractional laser versus Er:YAG fractional laser for atrophic acne scars: a meta-analysis and systemic review. J Cosmet Dermatol. 2024;23(9):2768-2778. doi:10.1111/jocd.16348
- Ismail SA. Long-pulsed Nd:YAG laser vs. intense pulsed light for hair removal in dark skin: a randomized controlled trial. Br J Dermatol. 2012;166(2):317-321. doi:10.1111/j.1365-2133.2011.10695.x
- Nuchanatanon T, Jurairattanaporn N, Vachiramon V. Nd:YAG technology for laser hair removal: what’s new? Dermatol Rev. 2024;5(4):e249. doi: 10.1002/der2.249
- Bäumler W, Breu C, Philipp B, Haslböck B, Berneburg M, Weiß KT. The efficacy and the adverse reactions of laser-assisted tattoo removal: a prospective split study using nanosecond and picosecond lasers. J Eur Acad Dermatol Venereol. 2021;36(2):305-312. doi:10.1111/jdv.17674
- Kassirer S, Zachary CB, Marini L, Adatto M, Landau M. Laser tattoo removal strategies: Part II: A review of the methods, techniques, and complications involved in tattoo removal. J Am Acad Dermatol. 2025;93(1):19-32. doi:10.1016/j.jaad.2024.05.097
- Spring LK, Krakowski AC, Alam M, et al. Isotretinoin and timing of procedural interventions: a systematic review with consensus recommendations. JAMA Dermatol. 2017;153(8):802-809. doi:10.1001/jamadermatol.2017.2077
- Waldman A, Bolotin D, Arndt KA, et al. ASDS Guidelines Task Force. Consensus recommendations regarding the safety of lasers, dermabrasion, chemical peels, energy devices, and skin surgery during and after isotretinoin use. Dermatol Surg. 2017;43(10):1249-1262. doi:10.1097/DSS.0000000000001166
- Lai D, Zhou S, Cheng S, Liu H, Cui Y. Laser therapy in the treatment of melasma: a systematic review and meta-analysis. Lasers Med Sci. 2022;37(4):2099-2110. doi:10.1007/s10103-022-03514-2
- McKesey J, Tovar-Garza A, Pandya AG. Melasma treatment: an evidence-based review. Am J Clin Dermatol. 2020;21(2):173-225. doi:10.1007/s40257-020-00488-w