The smarter, safer alternative: Solius maximizes UVB benefit and reduces UVA risk
Dermatologists have used UV phototherapy for more than a century. Solius is the next generation of dermatologist-guided light medicine.
Skin sensor
measures each user’s skin (ITA) to calculate a personalized dose
0.4 MED
target first dose
I-VI
validated for all Fitzpatrick skin types
FDA-cleared
new FDA product code SGZ, cleared for over-the-counter use
Recognized by the National Psoriasis Foundation
Solius Pro holds the NPF Seal of Recognition ↗
Live on published site
Over a century of light as medicine
UV phototherapy has been part of dermatology since the first Nobel Prizes in Medicine. Solius builds on that history with a measured, personalized dose of the most beneficial, but difficult to access part of the UV spectrum.
1903
Nobel Prize for UV light therapy
Niels Finsen receives the Nobel Prize in Medicine for treating lupus vulgaris, tuberculosis of the skin, with concentrated UV light.
1980s
Narrowband UVB
311 nm fluorescent narrowband UVB becomes a mainstay of in-office dermatology treatment for psoriasis, eczema, and vitiligo.
2026
Personalized UVB
Solius Pro becomes the first and only FDA-cleared, personalized UVB light therapy, dosed to each user’s measured skin.
Solius complements healthy sun habits
Solius adds a measured, personalized dose of the most beneficial part of the sun’s spectrum, with the least amount of risk.
01
Wear sunscreen
Protect skin from the unmeasured UV exposure of everyday sun.
02
Avoid midday sun
The UV-heavy midday sun carries the highest risk of burns and skin damage.
03
Personalize your UVB dose
Solius isolates UVB, the most beneficial wavelength of light medicine and the hardest spectrum of the sun’s light to dose safely.
04
Check your skin
Get an annual skin check with a dermatologist.
The Solius dosing technology
Solius automates the traditional phototherapy protocol and incorporates a skin measurement to set a maximum dose the user cannot exceed.
Solius maximizes UVB benefit and reduces UVA risk
UV-B
burning and benefits
UVB drives vitamin D production, nitric oxide release, neuroendocrine signaling, and microbiome balance. It is also the band that burns, which is why dose control matters.
UV-A
aging
UVA penetrates deeper, is tied to photoaging and skin damage, and adds little to vitamin D synthesis. Precision LEDs targeting 293 nm concentrate Solius light in UVB and limit UVA.
15-week clinical study
No skin color change
In Solius’s 15-week IQVIA protocol study, photos of each subject’s back taken at the start and end of the study showed no visible change in skin color.
Solius concentrates its output in UVB and limits UVA, the light that drives tanning, thus is designed not to tan or burn the skin.
How a Solius dose compares to a narrowband UVB dose
Narrowband UVB is prescribed in raw, unweighted energy. Solius doses are erythemally weighted (mJ/cm² effective), the standard scale that adjusts each wavelength for how the skin responds to it. Put on the same scale, the two doses compare directly.
Fitzpatrick I-II, first dose
Solius Pro (personalized first dose)
Narrowband UVB (AAD starting dose)
Unweighted energy
~9-14 mJ/cm²
300 mJ/cm²
Erythemally weighted
~8-12 mJ/cm² eff
~19 mJ/cm² eff
Share of MED
40%
~75-85%
Why the narrowband number is so much larger: The UVB action spectrum extends from 280 to 315 nm, and peaks around 297 nm. Narrowband lamps peak at 311 nm, which provide very little beneficial UVB energy; thus, a large amount of raw energy is needed to reach a therapeutic dose. Solius concentrates its light at 293 nm, inside the vitamin D/UVB action spectrum, so a small, precisely measured dose does the same work more efficiently and when properly dosed to the user’s skin, provides that dose more safely. For the same skin type, a Solius first dose is about half the erythemally weighted starting dose of narrowband UVB, and well below the erythema threshold.
Narrowband conversion and Solius values calculated from independent third-party Intertek spectral scans of Solius Pro and a narrowband UVB device (Philips PL-S 9W/01 lamp), using the CIE erythema reference action spectrum (ISO 17166/CIE S 007). Fitzpatrick I-II MED of ~20-30 mJ/cm² eff (Cole 2020; Colombian MED study 2020). Starting dose from the AAD-NPF phototherapy guidelines, Table VIII.
The risk
Risk compared to natural sunlight & narrowband UVB
Solius vs. natural sunlight
99% less UV risk
UV risk than natural sunlight for the same benefit
Solius vs. narrowband UVB
83% less UV risk
UV risk than narrowband UVB phototherapy, which carries ~5.7x the UV radiation risk of Solius
Solius Pro
UVB 97%
UVA 3%
Narrowband UVB (Philips PL-S 9W/01)
UVB 73.6%
UVA 26.4%
Natural sunlight (ASTM G173 AM 1.5)
UVB 1.6%
UVA 98.4%
For the same vitamin D benefit
Solius Pro
Narrowband UVB
Natural sunlight
Vitamin D-weighted dose (benefit)
24.5 mJ/cm²
24.5 mJ/cm²
24.5 mJ/cm²
Exposure time
2 minutes
~5 minutes
~25 minutes
Total UV delivered
29.1 mJ/cm²
~167 mJ/cm²
~6,900 mJ/cm²
UVA delivered
~0.8 mJ/cm²
~44 mJ/cm²
~6,800 mJ/cm²
UVB and UVA shares (315 nm cutoff) and doses are Solius engineering calculations from independent third-party Intertek spectral scans of Solius Pro (FDA 510(k) Summary) and of a narrowband UVB device with a Philips PL-S 9W/01 lamp at 20 cm, and from the ASTM G173 AM 1.5 reference sun spectrum. Narrowband exposure time is derived from its measured vitamin D-weighted irradiance.
Total UV risk
1 year
of weekly Solius therapy UV risk
=
5 minutes
of afternoon sun UV risk
The UV exposure risk of a full year of weekly Solius therapy is equivalent to the UV risk of five minutes of afternoon sun, based on typical two-minute weekly sessions.
The benefit
Benefit compared to natural sunlight & narrowband UVB
Holding exposure time constant at two minutes, a typical Solius session, this compares the vitamin D-weighted UVB dose each source delivers. Solius delivers far more beneficial UVB per minute by concentrating output where vitamin D synthesis peaks.
Solius vs. natural sunlight
12x
more vitamin D-stimulating UVB per minute than natural sunlight at mid-latitudes
Solius vs. narrowband UVB
2.6x
more vitamin D-stimulating UVB per minute than narrowband UVB phototherapy
Solius Pro
24.5 mJ/cm²
Narrowband UVB (Philips PL-S 9W/01)
~9.5 mJ/cm²
Natural sunlight (ASTM G173 AM 1.5)
2.0 mJ/cm²
Vitamin D-weighted UVB dose in two minutes of exposure. Solius and sunlight values are Solius engineering calculations from spectral measurements of Solius Pro and the ASTM G173 AM 1.5 spectrum (24.5 versus 2.0 mJ/cm², a 12.3x ratio). Narrowband is derived from its measured vitamin D-weighted irradiance, 2.58x lower than Solius.
Phototherapy has a long safety record. Solius makes it safer
Many patients with moderate-to-severe psoriasis or eczema move to systemic drug therapies, some of which are associated with a higher risk of skin cancer. Narrowband UVB phototherapy remains a guideline-recommended, drug-free option backed by decades of safety data.
TNF-alpha inhibitor biologics
Higher skin cancer risk
In a 2026 Journal of the American Academy of Dermatology cohort of 56,209 patients with chronic inflammatory disease, TNF-alpha inhibitor biologics were associated with ~1.9x the risk of any skin cancer, including higher risk of basal cell carcinoma (adjusted HR 1.99), squamous cell carcinoma (1.69), and melanoma (1.54).
Narrowband UVB phototherapy
No significant skin cancer association
In 3,867 patients followed for 24,753 person-years, Hearn and colleagues found no significant association between narrowband UVB treatment alone and basal cell carcinoma, squamous cell carcinoma, or melanoma (British Journal of Dermatology, 2008).
Where Solius fits
Recognized by the National Psoriasis Foundation
Solius Pro holds the National Psoriasis Foundation Seal of Recognition, which highlights products created to be non-irritating and safe for people living with psoriasis and psoriatic arthritis. Solius is cleared to stimulate vitamin D production, not to treat psoriasis or eczema, and treatment choices remain with the dermatologist and patient.
Engineered for safety
Layered safeguards built into the device and app, so safe use does not depend on judgment alone.
Personalized maximum dose
The skin sensor sets each user’s dose, and that dose is a ceiling: users cannot increase exposure beyond it or choose their own exposure time. Any reported redness lowers the next dose automatically.
Precise light
UVB LEDs targeting 293 nm concentrate output in UVB and limit UVA, with a consistent and uniform output across the therapy area.
Dynamic positioning
Distance sensing keeps users 7-14 inches from the panel, with visual and audio guidance in the app and automatic shutoff if they are not properly positioned.
Protective eyewear
Validated UVB-protective eyewear is included, and in-app facial detection confirms the eyes are protected before therapy can start.
One-day lockout
One session per day at most, giving skin time to show a response and preventing repeat therapies and over-exposure.
Designed not to tan or burn
Doses target 0.4 MED, below the erythema threshold, and limited UVA output means Solius is designed not to tan or burn the skin. In a 15-week clinical study, before-and-after photos showed no visible change in skin color.
The first and only FDA-cleared, personalized UVB light therapy
Cleared January 16, 2026 as a Class II device under a new product code, SGZ, created for personalized, sensor-dosed UVB for unsupervised use. Indicated to stimulate vitamin D production in people 22 and older.
Safety and effectiveness reviewed
FDA reviewed Solius’s clinical safety and effectiveness data, including the randomized controlled trial, dosing validation across all skin types, and the 15-week protocol optimization study.
Cleared for at-home use
Over-the-counter clearance required showing a layperson can use the device safely by following its labeling, with light output, safety testing, usability, and labeling all reviewed.
Is Solius right for you?
Cleared for adults 22 and older. Not for use with skin lesions or open wounds. Caution recommended for anyone with a personal or family history of skin cancer. Annual skin check with a dermatologist recommended.
How UVB light impacts your body
Neurotransmitters, nitric oxide, & hormones are activated
What happens
UVB light triggers the release of nitric oxide, beta-endorphins, serotonin precursors, dopamine-related peptides, and anti-inflammatory compounds like calcitriol and lumisterol.
Why it matters
These molecules improve mood, energy, stress balance, motor control and learning, and provide long-term neuroprotection against cognitive decline. Effects begin shortly after exposure and can last hours to days.
Vitamin D production begins, optimizing gene expression
What happens
Within seconds of UVB light exposure, your skin converts 7-dehydrocholesterol into previtamin D₃, which becomes active vitamin D₃ over the next 24-48 hours.
Why it matters
Vitamin D functions as a hormone that influences over 1,000 genes, supporting bone strength, immune resilience, and metabolic health.
Microbiome balance & gut integrity improves
What happens
UVB light strengthens your skin and gut microbiomes. On the skin, natural antimicrobial peptides increase, helping beneficial bacteria thrive while reducing inflammation. Through the gut-skin axis, UVB promotes amino acid and mucus production, supporting nutrient absorption, gut barrier integrity, and microbial diversity.
Why it matters
A balanced microbiome improves skin health and appearance, reduces chronic inflammation and supports digestion, immunity, and mood regulation. Local skin improvements begin within days, and gut microbiome diversity increases progressively over 2-4 weeks.
Featured UVB research
Solius’s own clinical studies, alongside leading research from dermatologists on the systemic effects of UV exposure.
Research partners
Vitamin D supplements are not a substitute for UVB
Supplements have not reproduced the benefits associated with sun exposure. The evidence increasingly points to vitamin D as a biomarker of UVB exposure, not the sole mediator of its effects. UVB is a fundamental input to human health in its own right.
Why do humans have different skin tones?
Early humans lived near the equator, mostly outdoors and largely unclothed, and had darker skin. As populations migrated toward the poles, skin pigmentation lightened over many generations.
The leading scientific explanation, developed by anthropologists Nina Jablonski and George Chaplin, comes down to UVB. It is the part of sunlight that drops most with distance from the equator, filtered by a longer path through the ozone layer, while UVA, visible light, and infrared light decline far less. Human skin evolved to be lighter so it could make the most of the limited UVB available farther from the equator.
Our need for UVB was strong enough to reshape the color of human skin. That is how fundamental UVB is to human health.
The sun is nearly impossible to dose safely
Modern indoor life and long winters away from the equator leave most people short on UVB, and even on clear summer days, a reliable dose from the sun is out of reach, so most people end up underexposed or intermittently burned.
Time of day
Effective UVB appears for only a few midday hours.
Season
A low sun angle blocks UVB much of the year.
Weather
Clouds, haze, and pollution absorb UVB.
Modern life
Glass, clothing, and sunscreen block UVB almost entirely.
Exposed skin
Benefit requires large areas of skin facing the sun.
Further reading from the Solius blog
Featured article
UVB Light Therapy: How It Works, What It Treats, and How to Get Started
From psoriasis, eczema, and vitiligo to broader systemic benefits, with commentary from board-certified dermatologist Dr. Matthew Zirwas.
Read article →
The Science of UVB Light: How It Works and Why It Matters
Why glass, season, latitude, and clothing keep UVB from reaching your skin.
Read article →
Sunlight Is a Pharmacy. Vitamin D Is Just One Drug.
Sunlight triggers vitamin D, nitric oxide, endorphins, and circadian signals. A pill can deliver one of those.
Read article →
UVA vs. UVB Light: What’s the Real Difference?
What each band of UV does, and how to get UVB’s benefits without the downsides.
Read article →
Types of Light Therapy and Why Each Matters
Phototherapy, photobiomodulation, and narrowband UVB are not the same thing.
Read article →
At-Home UVB Light Therapy: How It Works, Uses, and Safety
From prescription skin treatments to OTC devices: dosing, safety, and how to choose.
Read article →
UVB Light Benefits: Beyond Vitamin D
What research shows about UVB and mood, blood pressure, immunity, and the gut.
Read article →
Benefits of Sunlight: What Science Actually Shows
Endorphins, gut health, circadian signals, and more.
Read article →
Vitamin D 101: What It Is and What the Science Shows
Why vitamin D is a prohormone, how sunlight makes it, and what the research says.
Read article →
Recognized for innovation in health technology
Independent editors and judges have recognized Solius among this year’s most important advances in health and technology.
Bring personalized UVB to your practice
Email our team to ask about offering Solius therapy in your practice.