Red Light Therapy for Collagen: What Trials Measured
Red light therapy for collagen has trial support: in studies using skin biopsies and ultrasound, red and near-infrared light raised measures of collagen in the skin over weeks to months. The effect is moderate and builds slowly, with first changes around week 4 and more by month 3. Below: how collagen is measured, a month-by-month curve, wavelengths, trial settings, the neck, supplements and retinol, and a home routine.
Key takeaways
- In a sham-controlled trial of 76 people, 633 nm or 830 nm light, alone or together, twice a week for 4 weeks produced a "marked increase" in collagen and elastic fibres on skin biopsy. Lee, 2007
- In a 2014 study, 30 sessions of red light raised an ultrasound collagen score by 5.75 points, while the score of an untreated group fell by 0.26. Wunsch and Matuschka, 2014
- In a small 2023 study of a 630 nm home mask, dermal density on ultrasound rose 26.4% after 4 weeks and 47.7% after 12 weeks. Couturaud, 2023
- In a 2023 trial of 137 women, 660 nm red and 590 nm amber light cut wrinkle volume around the eyes by a similar amount: 31.6% and 29.9%. Mota, 2023
- A Harvard dermatologist says red light devices "must be used multiple times a week for four to six months". Harvard Health, 2025
Does red light therapy increase collagen production?
Trials suggest it does, gently and over time. In studies lasting 4 to 16 weeks, red and near-infrared light raised collagen on biopsy and dermal density on ultrasound.
Collagen is made by fibroblasts, cells in the dermis. The French public health information service explains that red light (630 to 700 nm) and near-infrared light (800 to 1200 nm) are thought to prompt these cells to make more of it. Santé.fr, 2026
Light is absorbed by cytochrome c oxidase, an enzyme in the cell's mitochondria. In fibroblasts, 660 nm light raised procollagen, the building block of collagen, and lowered the enzymes that break collagen down. Hernández-Bule, 2024
In the 2007 sham-controlled trial, treated skin had more collagen on biopsy and higher levels of TIMP-1 and TIMP-2, proteins that block those enzymes. Lee, 2007
The size of the effect is moderate. The AAD describes results as "subtle to noticeable". AAD, 2024 As our guide to red light therapy for loose skin puts it, light firms rather than tightens.
How do researchers know red light raised collagen?
They use three main tools: high-frequency ultrasound for dermal density, a biopsy to see the fibres, and a suction device for firmness and elasticity. None of them shows something you can see in a mirror, which is why photos over weeks matter at home.
| Method | What it measures | Light trials that used it | What you might notice at home |
|---|---|---|---|
| High-frequency ultrasound | Density of the dermis, where collagen sits, without cutting the skin | Wunsch 2014, Couturaud 2023, Lee 2021 (neck) | Nothing directly; skin may feel firmer over months |
| Biopsy under a microscope | The collagen and elastic fibres themselves | Lee 2007, Goldberg 2006 | Nothing directly |
| Suction device (Cutometer) | Firmness and elasticity, an indirect sign of collagen | Couturaud 2023, Lee 2021 (neck) | Skin that springs back a little faster |
| 3D imaging or skin replicas | Wrinkle depth and volume | Mota 2023, Nam 2017 | Softer lines in photos taken in the same light |
Biopsies are small but show the fibres. In a 2006 study of 36 people given 9 sessions of 633 nm and 830 nm light over 5 weeks, electron microscopy of 5 biopsies showed thicker collagen fibres. Goldberg, 2006
How long does red light take to build collagen?
Expect first changes around week 4, a fair judgement at week 8, and the biggest change by about month 3. Some reviews say the full effect can take up to six months.
The clearest month-by-month curve comes from the 2023 mask study. Twenty volunteers aged 45 to 70 used a 630 nm mask for 12 minutes twice a week, about 72 hours apart. Couturaud, 2023 Their dermal density on ultrasound rose at each check:
- Day 28: up 26.4%.
- Day 56: up 41%.
- Day 84: up 47.7%.
By day 84, firmness had improved by 23.6% and elasticity by 18.7%. It was a small study with no comparison group, but the shape of the curve is useful: density was still rising at 12 weeks.
The outer edge is longer. Santé.fr reports a review placing the maximum effect at 6 months or more. Santé.fr, 2026 Harvard's dermatologist gives four to six months of use several times a week. Our guide to how long red light therapy takes to work sets out the face timeline week by week.
Which wavelength is best for collagen: 630, 660, 850 or 1064 nm?
No single wavelength has won. Red at about 630 to 660 nm and near-infrared at about 830 to 850 nm both have trial support, and trials that compared colours found them performing alike.
Four trials put wavelengths side by side:
- 633 nm, 830 nm or both (2007): all three groups improved, and Santé.fr reports no significant difference between wavelengths. Santé.fr, 2026
- Red or broadband (2014): the collagen score rose 5.75 points with 611 to 650 nm red and 6.40 points with 570 to 850 nm broadband light, with no significant difference. Wunsch and Matuschka, 2014
- 660 nm or 590 nm (2023): wrinkle volume fell 31.6% with red and 29.9% with amber, in a split-face trial of 137 women. Mota, 2023
- 660 nm or white light (2017): wrinkles improved in both groups of 52 women using home devices, with a higher global improvement score for red. Healio, 2017
A 2024 review found "no agreement on the optimal wavelengths", with most studies using 630 to 950 nm. Hernández-Bule, 2024
For deep near-infrared, the closest evidence comes from a 2023 study of men using a mask with 633, 830 and 1072 nm. Over 6 weeks, wrinkles, texture and pores improved on self-assessment and photo analysis. Mineroff, 2023
What settings did collagen trials use, and is more light better?
Most used 9 to 15 minutes per session, from twice a week to daily, for 4 to 16 weeks. Where doses were reported, they ran from 3.8 to 15.6 J/cm² per session.
| Trial | Area | Wavelength | Dose per session | Minutes | Sessions per week | Weeks |
|---|---|---|---|---|---|---|
| Lee 2007 (76, sham-controlled) | Face | 633, 830 or both | Not in abstract | Not in abstract | 2 | 4 |
| Wunsch 2014 (128) | Whole body or face and chest | 611 to 650, or 570 to 850 broadband | About 8.5 to 9.6 J/cm² of red | 12 to 25 | 2 | About 15 (30 sessions) |
| Couturaud 2023 (20) | Face, mask | 630 | 15.6 J/cm² at 21.7 mW/cm² | 12 | 2 | About 12 |
| Lee 2021 (30) | Neck | 630 + 850 | About 13.5 J/cm² at 25 mW/cm² (our arithmetic) | 9 | 7 | 16 |
| Mota 2023 (137) | Around the eyes | 660 or 590 | 3.8 J/cm² | Not reported | About 2.5 (10 sessions) | 4 |
More light is not better. Light follows a biphasic dose response: a low dose stimulates cells, and a much higher dose loses the benefit. Huang, 2009 In mice, wounds healed best near 2 J/cm² and did worse than untreated wounds at 50 J/cm².
Collagen is laid down at its own pace, so longer or brighter sessions do not speed it up. Our article on how much red light therapy is too much covers the limits in more detail.
Does red light still build collagen after the menopause or in your 70s?
Trials that included older skin still recorded gains. The 2014 ultrasound study enrolled people aged 27 to 79, and the 2023 mask study people aged 45 to 70.
As our guide to red light therapy for skin over 50 explains, collagen and skin thickness fall by about 1 to 2% a year after the menopause. The face has not stopped making collagen, and aged skin still responds to stimulation: a retinol trial in people with an average age of 87, covered below, found new procollagen.
Can red light build collagen on the neck and chest?
The neck has its own trial: 630 nm and 850 nm light for 9 minutes a day over 16 weeks raised skin density and elasticity in 30 women. A face mask does not reach the neck or chest, so these areas need a panel.
The women were aged 30 to 47, with Fitzpatrick skin types III to V. Lee, 2021
- At 16 weeks: skin density on ultrasound, elasticity and hydration had all risen.
- Neck wrinkles: fewer, and still below baseline 8 weeks after stopping.
- Thyroid: volume went from 8.60 to 8.44 mL, not a significant change, and thyroid hormones were unchanged.
Our precautions still say not to use either device with a thyroid condition or thyroid medication. Our guide to red light therapy for the neck covers positioning in detail.
Do collagen supplements or retinol add to red light?
Retinol has its own biopsy evidence for new collagen, while the evidence for collagen supplements is contested. No study has tested either one together with red light.
On supplements, a 2025 meta-analysis pooled 23 randomised trials with 1,474 people. NutraIngredients, 2025
- Overall: the pooled results favoured supplements.
- Trials not funded by industry: no benefit.
- The debate: the authors concluded there is "no clinical evidence", and industry groups dispute their method.
Red light acts on the fibroblasts in the skin, while swallowed collagen is digested first. A doctor can help with questions about supplements.
In a trial of 36 adults with an average age of 87, 0.4% retinol lotion used up to 3 times a week for 24 weeks raised procollagen I on biopsy compared with an inactive lotion. Kafi, 2007 Fine wrinkles improved too.
If you use both, our guide to red light masks and retinol sets out the order: light first, retinol after. Introduce one product at a time, 2 to 4 weeks apart. Skip the mask while retinol has left skin red, raw or peeling.
Do collagen gains last after you stop?
In trials, gains held for weeks after the last session. Plan a regular rhythm rather than a one-off course.
- Face mask study: results held 14 and 28 days after stopping. Couturaud, 2023
- Neck study: wrinkles stayed below baseline 8 weeks after stopping. Lee, 2021
- Ultrasound study: at the later follow-up, the collagen score was still 5.10 points above baseline, a little below its level at the end of the course. Wunsch and Matuschka, 2014
The AAD calls red light "not a one-and-done treatment", because skin keeps ageing. AAD, 2024
Is red light for collagen suitable for darker skin?
It can be, with more care, because the AAD notes that darker skin is more sensitive to visible light and can develop dark patches. AAD, 2024 Start at lower settings and talk to a dermatologist first.
Harvard's advice is that darker skin should "start with lower doses". Harvard Health, 2025 A 2024 review notes that skin of colour tolerated a red-light dose up to 50% lower. Hernández-Bule, 2024 The neck trial included Fitzpatrick types III to V.
Our precautions advise against using the panel on Fitzpatrick skin types V and VI. With the mask, start at the lowest brightness.
How do you use the Kivorla mask and panel for a collagen routine?
Use the mask on the red mode for the face and the panel for the neck and chest, each within its own limits. Both carry red and near-infrared wavelengths close to those in the collagen trials.
The 4-Wavelength Red Light Therapy Mask is a cordless, food-grade silicone shell that covers the face, with one eye opening and no diodes over the eyes. The red mode runs 665 nm red with 850 nm and 1064 nm near-infrared. It carries 164 VCSEL laser diodes: 72 at 665 nm, 72 at 850 nm and 20 at 1064 nm. The blue mode, 460 nm blue with 850 nm, is not part of a collagen routine. Brightness is set at 50, 70 or 90%, with a 5, 10 or 15-minute timer.
- Week 1: Red mode at 50% brightness on clean, dry skin, with the 10-minute timer, then 70% or 90% if skin stays comfortable.
- How often: the trials ran from twice a week to daily. The manual allows 10 minutes up to 4 times a week at high brightness, or 15 minutes up to 3 times a week, and never more than 20 minutes a day.
- To stay near the studied range: keep to 2 to 4 sessions a week, using 50% or the 5-minute timer if skin is dry or reactive.
- Skincare and tracking: serums or retinol after the session, sunscreen every morning, and photos in the same light at weeks 0, 4, 8 and 12.
The 9-Spectrum Red Light Therapy Panel has nine channels: 480, 590, 630, 660, 670, 810, 830, 850 and 1060 nm, each dimmable from 1 to 100%. Its 630, 660, 830 and 850 nm channels match the collagen trials. At 640 x 230 mm, it hangs on a door or wall with the included door hook, pulley, hanging cables and screws, or stands upright on the floor.
- Position: hang it on a door or wall at the height of your neck and upper chest, about 12 inches away, chin slightly raised.
- Channels: turn up 630, 660, 830 and 850 nm, and turn the rest down.
- To match the studied range: the neck trial used 25 mW/cm² for 9 minutes, so dim each channel well below 100%, keep the 12-inch distance and set a short timer. The timer starts at 1 minute, and the panel stops at 5 minutes if no time is set.
- Upper limit: our suggestion is 10 to 15 minutes per area, with at least 6 hours between 30-minute sessions.
- Eyes: wear the included goggles and keep your eyes closed.
A controller and goggles come with the panel.
Standard shipping to the US, UK and Germany is free. Read the precautions before ordering. Under our return and refund policy, returns are accepted within 30 days: an unopened device with its seals intact is refunded less a 10% restocking fee, and an opened device that is undamaged and complete is refunded less 20%.
Kivorla devices are general wellness devices, not medical devices, and are not intended to treat any skin condition. Talk to a dermatologist before starting if you have darker skin, a light-sensitive condition or take light-sensitising medicine, and ask your doctor about supplements.