The science behind Lumière™

The science

Photobiomodulation: how visible and near-infrared light changes what skin cells do.

This page goes beyond the product. It explains the mechanism, why the dose matters more than the power, what published studies have measured, and where the evidence stops. Every study is referenced at the bottom.

The mechanism

From a photon to a firmer skin, in four steps

Red and near-infrared light are not absorbed at random. The best-studied target is an enzyme inside the mitochondria, the cell's energy centre. What follows is a chain reaction, described in detail by Hamblin (2018).

  1. AbsorptionPhotons are absorbed by cytochrome c oxidase, the last enzyme of the mitochondrial respiratory chain.Cytochrome c oxidase
  2. ReleaseLight frees nitric oxide (NO) that was blocking the enzyme. Oxygen can bind again and the chain speeds up.Nitric oxide · O₂
  3. EnergyThe mitochondria produce more ATP, the cell's fuel, and a brief, controlled pulse of signalling molecules.ATP · ROS signal
  4. ResponseThat signal switches on genes for repair: fibroblasts make more collagen and elastin, inflammatory messengers calm down.Fibroblasts · collagen
Depth

Each wavelength works at its own depth

Skin filters light. Short wavelengths are absorbed near the surface, longer ones travel further before they are used up. That is why a wavelength is chosen for where its target lives.

Blue light is absorbed in the epidermis, where acne bacteria produce light-sensitive porphyrins. Red reaches the dermis, home of the fibroblasts that make collagen. Near-infrared, invisible, goes deepest and supports the cells' energy and recovery.

470 nmBlue · surfaceAcne bacteria520 nmGreen · upper skinRedness, uneven tone630 nmRed · dermisFibroblasts, collagen850 nmNear-infrared · deepestCellular energyEPIDERMISDERMISHYPODERMISLUMIÈRE™ LIGHT
  • 470 nm · Blue · surface · Acne bacteria
  • 520 nm · Green · upper skin · Redness, uneven tone
  • 630 nm · Red · dermis · Fibroblasts, collagen
  • 850 nm · Near-infrared · deepest · Cellular energy
Relative depth, illustration not to scale.
Too littleTherapeutic windowToo much Energy delivered (dose) Effect on the skin
Schematic, based on the biphasic dose response described by Huang et al., 2011.
Dose

More light is not better light

Photobiomodulation follows a biphasic dose response, sometimes called the Arndt–Schulz curve. Too little energy does nothing. The right amount stimulates. Too much can cancel the benefit (Huang et al., 2011).

The dose depends on two things: irradiance (mW/cm², how much light arrives each second) and time. This is why sessions are short, why there are rest days in the maintenance phase, and why doubling your sessions will not double your results.

Evidence

What the studies have measured

A selection of peer-reviewed clinical studies. They used clinical devices with their own settings, so their numbers are not a promise for any home device, ours included. They show what the light can do when the dose is right.

  • Collagen · wrinklesControlled trial

    30 sessions136 volunteers, twice a week, red and near-infrared light

    Collagen density measured by ultrasound rose significantly in both treated groups, not in the untreated controls. Fine lines and roughness improved.

    Wunsch & Matuschka, 2014 [3]

  • Wrinkles · elasticityControlled trial

    up to −36%wrinkle depth · up to +19% elasticity

    76 patients, split-face and placebo-controlled, 633 nm, 830 nm or both, 8 sessions over 4 weeks. Biopsies showed more collagen and elastic fibres.

    Lee et al., 2007 [4]

  • Firmness · densitySmall study

    3 months20 participants, 630 nm, twice a week

    Crow's feet depth, dermal density, firmness and pore size all improved on instrument measurements. Small group, no placebo arm.

    Couturaud et al., 2023 [5]

  • BreakoutsControlled trial

    −76%inflammatory lesions after 12 weeks

    107 patients with mild to moderate acne. Blue and red light combined, 15 minutes daily. Comedones fell by 58%. Combining wavelengths is what Lumière™ does in its purple mode.

    Papageorgiou et al., 2000 [6]

  • PigmentationEmerging

    Green light505 nm, cell and human study

    Green light reduced melanin production in cells and lowered facial pigmentation in volunteers. Promising, still early.

    Mima et al., 2025 [7]

Our choice

Why 470 nm, and not 415 nm

Many LED devices use violet-blue light at 415 nm. With Dr Le Goff, the dermatologist who works with C'est Madeleine and has more than 30 years of experience, we chose 470 nm, always paired with 850 nm near-infrared. Here is the reasoning.

Common in acne devices

415nm

  • In a lab model of the retina, cell damage peaked between 415 and 455 nm [8].
  • At high doses, 412–426 nm light was toxic to skin cells [9].
  • 415 nm induced dose-dependent pigmentation, where red light did not [10].
Lumière™ blue

470nm

  • Retinal cells exposed around 480 nm stayed healthy in the same lab model [8].
  • Blue light at 453 nm stayed non-toxic to skin cells up to very high doses [9].
  • Further from the blue-light hazard peak for the eyes (435–440 nm).
  • Always paired with 850 nm near-infrared: in laboratory research, red and near-infrared light protected cells against blue-light damage and lowered oxidative stress [11].

The result: a blue that purifies with a gentler profile for the eyes and for skin prone to dark spots, supported by near-infrared in every session, and built-in eye shields on every mask.

Honesty

Where the evidence stops

  • Results vary. Skin type, age, regularity and the rest of your routine all change the outcome. Studies report averages.
  • Clinics are not homes. Most trials use clinical panels at fixed distances and doses. Home masks rely on regularity over weeks.
  • Cosmetic, not medical. LED light supports skin that is healthy. It does not treat a disease and does not replace a dermatologist.
  • Some colours have less data. Red, near-infrared and blue are the best studied. Green and combined colours have fewer trials so far.
Applied

What this means for Lumière™

  • Near-infrared every timeThe deepest-reaching light is paired with every colour, so each session also supports cellular energy.
  • Wavelengths by target630 nm for the dermis, 470 nm for the surface, 520 nm to calm. Combined modes add them together.
  • A dose you can adjustFour intensity levels and 10 to 15-minute sessions, to stay in the therapeutic window.
  • Rhythm over intensityAn intensive phase, then maintenance with rest days, as the dose-response curve suggests.

Which light fits your skin? Two minutes, seven questions, a protocol built on this science.

Take the free skin diagnosis
References

Sources cited on this page

  1. Hamblin MR. Mechanisms and mitochondrial redox signaling in photobiomodulation. Photochemistry and Photobiology, 2018. doi:10.1111/php.12864
  2. Huang YY, Sharma SK, Carroll J, Hamblin MR. Biphasic dose response in low level light therapy: an update. Dose-Response, 2011. doi:10.2203/dose-response.11-009.Hamblin
  3. Wunsch A, Matuschka K. A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase. Photomedicine and Laser Surgery, 2014. doi:10.1089/pho.2013.3616
  4. Lee SY, Park KH, Choi JW, et al. A prospective, randomized, placebo-controlled, double-blinded, and split-face clinical study on LED phototherapy for skin rejuvenation. Journal of Photochemistry and Photobiology B, 2007. PubMed 17566756
  5. Couturaud V, et al. Reverse skin aging signs by red light photobiomodulation. Skin Research and Technology, 2023. doi:10.1111/srt.13391
  6. Papageorgiou P, Katsambas A, Chu A. Phototherapy with blue (415 nm) and red (660 nm) light in the treatment of acne vulgaris. British Journal of Dermatology, 2000. PubMed 10809858
  7. Mima Y, et al. Inhibitory effect of 505 nm green light emitting diode on melanin synthesis in cellular experiments and a human intervention study. Acta Dermato-Venereologica, 2025. Acta Derm Venereol
  8. Arnault E, Barrau C, Nanteau C, et al. Phototoxic action spectrum on a retinal pigment epithelium model of age-related macular degeneration exposed to sunlight normalized conditions. PLoS One, 2013. doi:10.1371/journal.pone.0071398
  9. Liebmann J, Born M, Kolb-Bachofen V. Blue-light irradiation regulates proliferation and differentiation in human skin cells. Journal of Investigative Dermatology, 2010. PubMed 19675580
  10. Duteil L, Cardot-Leccia N, Queille-Roussel C, et al. Differences in visible light-induced pigmentation according to wavelengths: a clinical and histological study in comparison with UVB exposure. Pigment Cell & Melanoma Research, 2014. doi:10.1111/pcmr.12273
  11. Heinig N, et al. Photobiomodulation mediates neuroprotection against blue light induced retinal photoreceptor degeneration. International Journal of Molecular Sciences, 2020. doi:10.3390/ijms21072370

Lumière™ is a cosmetic device for home use. It does not replace medical advice or treatment. Please read our precautions for use before your first session.

The science is in the dose. The results are in the regularity.

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