Is the Thulium Laser Safe for Darker Skin Tones?

By Alexander E. Bonato, MD — Board-Certified in Internal Medicine · Medically reviewed October 2026

TL;DR: The 1927 nm thulium laser can improve selected pigment concerns, but post-inflammatory hyperpigmentation remains a risk in darker skin tones. Studies are encouraging but small, with particularly limited evidence for Fitzpatrick V–VI. There is no dependable percentage that predicts your individual risk. Treatment settings, the condition being treated and your pigment history all matter. A consultation may lead to conservative treatment, postponement or a different approach.

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I train jiu-jitsu, and I've been tapped out by a purple belt who outweighed me by nothing and had every physical disadvantage on paper. He was better with less. I had more strength, more reach, and a completely wrong idea about what actually mattered. My WHOOP recovery score the next morning read like an incident report.

There's a version of that lesson that applies directly to the 1927 nm thulium laser , and it matters most for the specific question I get from patients with deeper skin tones: is this laser actually safe for me, or is it going to leave a dark patch where the sun spot used to be? The honest answer is that more energy isn't automatically better, and for skin that responds to inflammation with more pigment, being precise beats going in hot every time.

The Real Risk: Post-Inflammatory Hyperpigmentation

A key concern in darker skin is post-inflammatory hyperpigmentation, or PIH. Scarring and other complications are also possible. PIH is a patch of skin that darkens instead of clearing after the inflammation from a laser treatment settles down. It happens because skin with more melanin has melanocytes that respond to injury by overproducing pigment, enthusiastically, the way I respond to literally any home-improvement task. It isn't a flaw in anyone's skin. It's just how melanin-rich skin responds to inflammation, and it means the calculation for anyone with a deeper skin tone is genuinely different from the calculation for someone who tans easily and burns rarely.

This piece is specifically about candidacy and safety. If you're weighing this laser for precancerous spots specifically , I covered that evidence separately.

What Studies of 1927 nm Lasers Actually Show

Direct 1927 nm data in Fitzpatrick IV to VI is thinner than I'd like, and I want to say that plainly before anything else. But what exists is more reassuring than the reputation lasers have earned in darker skin. In one study, 61 patients being treated specifically for existing PIH, all Fitzpatrick IV to VI, went through low-energy 1927 nm sessions with zero adverse events reported. In another, 40 patients with Fitzpatrick III to V and facial hyperpigmentation went through a relatively high-setting protocol, and the worst thing that happened was a week of mild peeling. A third study of 23 patients spanning Fitzpatrick I through VI, including Fitzpatrick IV specifically, saw one case of transient pigment darkening around the mouth, which resolved on its own within two months with no treatment needed.

These studies are encouraging, but they used different devices, settings and patient groups. They do not establish a complication rate for our NOUVADerm treatments. The often-quoted 0%–18% range comes from a review covering both 1550 and 1927 nm studies; it should not be presented as a thulium-only risk estimate. Lower energy and lower density mean fewer events. That's not a coincidence, and it's a lot more reassuring than the version of this story that gets passed around in comment sections. It's the whole point of what comes next.

Why Settings—and Skin History—Matter

A review of 961 treatments with a 1550 nm fractional laser found PIH more frequently in darker skin types. That supports taking skin type seriously, but those are not 1927 nm thulium results, and the darkest groups were too small to supply a reliable personal risk estimate.

For 1927 nm treatment, energy and treatment density also matter. Conservative settings may reduce risk, but they cannot eliminate it.

One published expert-panel recommendation for treating dyschromia with the Fraxel system suggests roughly 50% coverage for Fitzpatrick I–III versus 25%–40% for IV–VI. Those are device-specific expert recommendations—not universal settings or numbers to transfer directly to NOUVADerm.

More strength did not save me on the jiu-jitsu mat. More energy is not automatically the answer here either. The goal is an appropriate treatment for the person in front of me, with an honest discussion of its limits.

Graduated measuring spoons from smallest to largest, a metaphor for calibrating laser settings to the individual.

What Actually Helps Prevent It

Risk reduction starts with choosing an appropriate treatment and settings, protecting the skin from sun exposure, and following individualized preparation and aftercare instructions.

Studies have examined additional preventive measures, including topical corticosteroids and tranexamic acid, but they involve different lasers and protocols. They do not provide a universal medication recipe for every thulium patient.

Sun protection remains an essential part of care. A finding that sunscreen alone did not prevent every case of PIH does not make it optional.

Medication choices depend on your medical history and the treatment planned. Tell me about previous pigment changes, melasma and cold sores before treatment. Precise beats aggressive—and preparation is part of precision.

You can read more about the treatment itself on our laser skin rejuvenation in Medford page.

Who Should Be Extra Careful

If you've had PIH before, from this laser, another laser, or even from a bad breakout, that history matters and I want to know about it before we start. The same goes for active melasma, since inflammation can worsen it in some patients regardless of treatment type. A history of PIH does not automatically rule out treatment, but active melasma or other risk factors may change whether laser treatment is appropriate. Sometimes the better plan is to stabilize the pigment first, postpone treatment or choose another option.

Frequently Asked Questions

Will this definitely cause dark spots on my skin?

No. PIH is possible, not inevitable. However, reassuring results from small studies cannot guarantee your outcome, and pigment changes can last longer than a few weeks.

Why do some clinics use much higher settings than others?

Because higher settings can mean faster results, and not every provider adjusts for skin tone the way the safety data suggests they should. Some of that is just enthusiasm outrunning caution, which I recognize, because it's basically my entire relationship with power tools. It's a real difference between practices, and it's worth asking directly what density and energy someone plans to use on you specifically, not just what they use on everyone who walks in.

How many sessions will I need if my settings are more conservative?

That depends on the condition, settings and your response. Conservative treatment may require more sessions, but the research does not establish one schedule that works for every skin type.

Does that mean my results will be worse?

Not necessarily. Improvement has been reported with conservative settings, but I cannot promise the same result from every treatment plan. We balance the potential benefit against the risks for your skin.

What if I've had melasma or PIH before?

Tell me before booking treatment. That history can change the preparation, treatment choice and timing—and sometimes means another approach is preferable.

The Bottom Line

If you've been told a laser isn't an option for your skin tone, or you're just being careful because you've read the horror stories, that's a conversation worth having in person instead of guessing from a blog post. Bring your history, including anything that's happened with lasers or breakouts before, and we'll build a plan around your actual skin, not a generic one. We see patients from Medford, Ashland, and Grants Pass, and the settings conversation is one I take seriously with every single person in the chair. Book a consultation

References

1. Goldman MP, Wu DC, Khetarpal S, et al. Dual 1550-nm Erbium Glass Fiber and 1927-nm Thulium Fiber Non-ablative Fractional Laser System Treatment in Patients With Skin of Color: A Review of Clinical Studies and Unmet Needs. Lasers Surg Med. 2026;58(3):169-179.
2. Geronemus RG, Wang JV, Jacobson AA, Marmur ES, Polder KD. Safety and Tolerability of the 1440- and 1927-nm Non-Ablative Fractional Diode Laser System for Skin Resurfacing: A Review of Current Literature. J Cosmet Dermatol. 2025;24:e70523.
3. Wongdama S, Yenyuwadee S, Li JB, et al. Interventions to Prevent Postinflammatory Hyperpigmentation After Laser and Energy-Based Device Treatments: A Systematic Review and Network Meta-Analysis. Lasers Surg Med. 2026;58(3):157-168.
4. Hu S, Atmakuri M, Rosenberg J. Adverse Events of Nonablative Lasers and Energy-Based Therapies in Subjects with Fitzpatrick Skin Phototypes IV to VI: A Systematic Review and Meta-Analysis. Aesthet Surg J. 2022;42(5):537-547.
5. Bae YC, Rettig S, Weiss E, Bernstein L, Geronemus R. Treatment of Post-Inflammatory Hyperpigmentation in Patients With Darker Skin Types Using a Low Energy 1,927 nm Non-Ablative Fractional Laser. Lasers Surg Med. 2020;52(1):7-12. (As cited in Geronemus et al. 2025.)
6. Vanaman Wilson MJ, Jones IT, Bolton J, Larsen L, Fabi SG. The Safety and Efficacy of Treatment With a 1,927-Nm Diode Laser With and Without Topical Hydroquinone for Facial Hyperpigmentation and Melasma in Darker Skin Types. Dermatol Surg. 2018;44(10):1304-1310. (As cited in Goldman et al. 2026 and Geronemus et al. 2025.)
7. Brauer JA, Alabdulrazzaq H, Bae YS, Geronemus RG. Evaluation of a Low Energy, Low Density, Non-Ablative Fractional 1927 nm Wavelength Laser for Facial Skin Resurfacing. J Drugs Dermatol. 2015;14(11):1262-1267. (As cited in Geronemus et al. 2025.)
8. Graber EM, Tanzi EL, Alster TS. Side Effects and Complications of Fractional Laser Photothermolysis: Experience With 961 Treatments. Dermatol Surg. 2008;34(3):301-305. (As cited in Goldman et al. 2026 — 1550-nm companion-wavelength data illustrating the Fitzpatrick/PIH gradient, not 1927-nm specific.)
9. Friedman PM, Dover JS, Chapas A, et al. 1,550 nm Erbium-Doped and 1,927 nm Thulium Nonablative Fractional Laser System: Best Practices and Treatment Setting Recommendations. Dermatol Surg. 2022;48(2):195–200. https://pubmed.ncbi.nlm.nih.gov/35050945/