How Long Should You Do Red Light Therapy? Minutes per Session

How long should you do red light therapy? For most home devices, 10 to 15 minutes per area is the usual session, and the best length is the one your device's manual sets for its own light output. Below: trial minutes by goal, why devices differ, distance, two sessions a day, beginner settings and how to time our mask and panel.

Key takeaways

• In a 2025 sham-controlled trial, a home mask used for 9 minutes five times a week improved crow's feet in 86.2% of users, against 16.7% with sham. Park, 2025
• In a home mask study using 12-minute sessions twice a week, crow's feet depth was 38.3% lower by day 84. Couturaud, 2023
• Clinic skin lamps ran 12 to 25 minutes per session, twice a week for 30 sessions, with the minutes set by each unit's output. Wunsch, 2014
• In muscle research, doses of 120 to 300 J for large muscle groups did better than higher doses. Leal-Junior, 2019
• The American Academy of Dermatology says "The amount of time needed varies, so follow the directions that come with the device." AAD

How long should you do red light therapy in one session?

Most home sessions run 10 to 15 minutes per area, and trials used anywhere from 8 to 25 minutes on the face, body and scalp. The right length is the one your device's manual sets, because minutes only make sense alongside the light output of that device.

Harvard Health notes that scientists have not settled exactly how long each session should last, and says devices "must be used multiple times a week". Harvard Health, 2025

Goal	Study	Light	Output or dose	Minutes per session	Sessions per week	Weeks
Face lines, home mask	Park, 2025	630 + 850 nm LED	Up to 10 mW/cm²	9	5	12
Face lines, home mask	Couturaud, 2023	630 nm LED	21.7 mW/cm²	12	2	12
Face skin, LED mask	Bragato, 2022	660 nm LED	6.4 mW/cm²	21	2 or 3	4
Face and body skin, lamps	Wunsch, 2014	Red or broadband	5.9 to 13.3 mW/cm² red	12, 15, 20 or 25	2	30 sessions
Acne, lamps	Papageorgiou, 2000	415 + 660 nm	Not in summary	15	7	12
Hair, home helmet	Lanzafame, 2014	655 nm	67 J/cm² per session	25	Every other day	16
Hair, laser comb	Jimenez, 2014	655 nm	Matched across models	8, 11 or 15	3	26
Muscles, before training	Leal-Junior, 2019	640 to 950 nm	120 to 300 J, large muscles	At least 30 seconds per point	Each training session	Varies
Knee pain	Stausholm, 2019	785 to 860 nm	4 to 8 J per point	Set in joules, not minutes	Varies	About 3.5 on average

This article covers minutes per session. For the number of weeks before a change shows, see how long red light therapy takes to work. For sessions per week, see how often to use red light therapy.

Why do studies use such different session lengths?

Each device puts out a different amount of light, so researchers set the minutes to reach a target dose. A low-output lamp needs longer to deliver what a stronger device gives in less time.

Dose is the light landing on the skin multiplied by time:

• Masks: one mask ran at 6.4 mW/cm² for 21 minutes Bragato, 2022, while another, at up to 10 mW/cm², ran for 9 minutes. Park, 2025
• Lamps: in the 2014 lamp trial, different units ran 12, 15, 20 or 25 minutes and landed at a similar red dose of about 9 J/cm² per session. Wunsch, 2014
• Laser combs: models were timed at 15, 11 and 8 minutes so that all three delivered similar doses: more beams, fewer minutes. Jimenez, 2014

So 10 minutes on one device and 20 on another can both be sensible.

How long to do red light therapy on face skin?

Face trials with LED masks used 9, 12 and 21 minutes per session, and clinic face and body lamps used 12 to 25 minutes. A home mask set to 10 or 15 minutes, as its manual directs, sits inside that range.

• 9 minutes, five times a week: crow's feet improved in 25 of 29 mask users and 5 of 30 with sham at 12 weeks. Park, 2025
• 12 minutes, twice a week: sessions were about 72 hours apart, and dermal density was 47.7% higher at day 84. Couturaud, 2023
• 21 minutes, two or three times a week: after 4 weeks, satisfaction rates were 79.6% with three sessions a week and 73.4% with two, both above sham. Bragato, 2022
• 15 minutes daily for acne: blue and red lamps lowered inflammatory spots by 76% at 12 weeks. Papageorgiou, 2000

A 2007 split-face trial of 633 and 830 nm light, twice a week for four weeks, found wrinkles reduced by up to 36%. Lee, 2007 In clinics, Cleveland Clinic says a session "usually lasts about 20 minutes". Cleveland Clinic

A mask sits at a fixed distance, so each minute delivers a steady amount of light. Keep your eyes closed throughout. Our guide on how to use a red light mask covers the routine step by step.

Is 20 or 30 minutes of red light therapy too much?

It depends on the device: 20 to 25 minutes was normal for low-output lamps in trials, but a longer session is not better in itself. Stay within your device's limits, such as our mask's cap of 20 minutes a day.

A 2009 review describes a two-sided pattern: too little light gives no response, a moderate amount stimulates, and too much can turn stimulation into inhibition. Huang, 2009 Its summary: "LLLT delivered at low doses tends to work better", mostly from cell and animal work.

In people, the clearest signals come from muscle and knee research:

• Muscles: where trials compared 120 to 300 J with more than 300 J for large muscle groups, the 120 to 300 J doses performed better. Leal-Junior, 2019
• Knees: a review of 22 trials with 1,063 people found pain 14.2 mm lower than placebo on a 100 mm scale across all trials, and 18.7 mm lower at recommended doses. Stausholm, 2019

A safety trial in 115 adults tested how much red light skin tolerates, using 633 nm at 87.2 mW/cm². Jagdeo, 2020 Its lowest dose took 30 minutes and its highest took two hours. Blistering appeared only at the top doses, far above those used in skin trials.

The right dose matters more than extra minutes. Our article on how much red light therapy is too much lists the signs that a session was too strong.

How long per area for knees, back and other body areas?

With a panel, 10 to 15 minutes per area is the usual home guidance, about 6 inches from a joint and about 12 inches from a broad area such as the back. Knee trials set their dose in joules per point rather than minutes, so trial times do not carry over directly.

The recommended knee doses were 4 to 8 J per treatment point at 785 to 860 nm, over an average course of about 3.5 weeks. Stausholm, 2019

• One joint: knee, elbow, wrist or ankle at about 6 inches, 10 to 15 minutes.
• Broad areas: back, chest or both thighs at about 12 inches, 10 to 15 minutes.
• Neck or jaw: side-on or from behind, never facing the panel, goggles on.
• Several areas: treat them one after another, 10 to 15 minutes each, rather than one long session on a single area.

How long before a workout should you use red light?

Most muscle trials applied light shortly before exercise, and clinical recommendations suggest 5 to 10 minutes before strength training. Sessions in those trials were short, at least 30 seconds per point on the muscle.

A review of exercise trials found that most applied light before exercise, with the clearest results at 5 to 6 J per point. Leal-Junior, 2015

The 2019 recommendations add a wider window for short-term effects: 5 minutes to 6 hours before activity. Leal-Junior, 2019

With a panel, a practical routine is 10 to 15 minutes on the muscles you are about to train, about 12 inches away for the thighs, then start your session. See red light therapy before or after a workout for timing.

How long do scalp sessions for hair growth last?

Hair trials used 25 minutes every other day with a home helmet, and 8 to 15 minutes three times a week with laser combs. Results were measured after 16 to 26 weeks.

The helmet trial ran 60 sessions over 16 weeks at 655 nm, and hair counts rose more than with sham. Lanzafame, 2014 In the comb trials, women using the 9-beam model gained 20.2 hairs per cm², against 2.8 with sham, at 26 weeks. Jimenez, 2014

Our mask does not cover the scalp; the panel reaches it from the side or from behind, chin down for the hairline, goggles on and eyes closed, never facing the panel.

Does distance from the panel change how long you need?

Yes: the closer the panel, the more light reaches the skin each minute, and the further away, the less. That is why session guidance always pairs a time with a distance.

In the 2020 safety trial, one small blister happened when a participant pressed her arm against the device, which "likely increased the delivered dose". Jagdeo, 2020 Cleveland Clinic's directions for home handheld tools pair the two as well: "6 to 12 inches from your face for 10 minutes". Cleveland Clinic

For our panel, 6 inches suits a single joint and 12 inches suits a broad area, and the skin at 12 inches receives much less light each minute. Stepping back is an easy way to make a session gentler without changing the timer.

Can you do red light therapy twice a day?

Most trials gave one session a day at most, and many spaced sessions two or three days apart. Our panel's manual asks for at least 6 hours between 30-minute sessions, and our mask is limited to 20 minutes a day.

The 12-minute mask study spaced sessions about 72 hours apart, and the hair helmet ran every other day.

Lab work points the same way: in skin cells, two doses three days apart helped while three on one day did not, and in rats a spaced daily schedule and a crowded one had different effects in the brain. Hawkins, 2007 Arias, 2020

Cleveland Clinic describes "one to three times a week for weeks or even months". Cleveland Clinic Spreading sessions across the week fits the research better.

How long should a first session be if you are new or have sensitive skin?

Start shorter and gentler than the maximum: a 10-minute mask session at 50% brightness, or a panel session with a shorter timer, dimmed channels and the panel about 12 inches away. Build up over a week or two if your skin stays calm.

• Mask: use the 10-minute timer at 50% for the first week, and move to 15 minutes only after a week of three 10-minute sessions.
• Panel: start about 12 inches back with a shorter timer and lower channels, then move to about 6 inches for a joint once used to it.
• Darker skin: Harvard Health says people with darker skin "should start with lower doses". Harvard Health, 2025 Our panel is not for Fitzpatrick skin types V or VI.
• Eyes: eyes closed every session, goggles on with the panel, and never look into either device.

A brief warm flush that fades within the hour is normal. If skin stings or stays red for hours, shorten, dim or step back. Our precautions rule out photosensitising medication, so anyone taking a medicine should check with their pharmacist or doctor before using the device.

How long are sessions with the Kivorla mask and panel?

On the mask, set 10 minutes for up to four sessions a week at high brightness, or 15 minutes for up to three, and never more than 20 minutes a day. On the panel, set 10 to 15 minutes per area, with at least 6 hours between 30-minute sessions.

The 4-Wavelength Red Light Therapy Mask is a full-face silicone shell with an eye opening and no diodes over the eyes:

• Timer: 5, 10 or 15 minutes; the mask switches off by itself when the timer ends.
• Brightness: 50, 70 or 90%, set by voice or the handheld controller.
• Modes: the red mode (665 + 850 + 1064 nm) and the blue mode (460 + 850 nm). To use both, alternate them on different days and count both against the weekly limits.
• Battery: around 40 minutes of use per charge, about 3.5 hours to charge; it cannot be used while charging.
• Skin: use on clean, dry skin with your eyes closed. For the jaw, neck or scalp, use the panel.

The 9-Spectrum Red Light Therapy Panel carries 480, 590, 630, 660, 670, 810, 830, 850 and 1060 nm:

• Timer: 1 to 30 minutes, set with the controller; if no time is set, the panel stops at 5 minutes.
• Distance: about 6 inches for a joint, about 12 inches for a broad area.
• Channels: each wavelength dims from 1 to 100%.
• Position: hang it on a door or wall with the included door hook, pulley, hanging cables and screws, or stand it upright on the floor. The surface stays at or below 40°C.
• Eyes: the supplied goggles on for every session. For the face, use the mask instead.

To stay near the studied range, use a shorter timer (it starts at 1 minute), dim each wavelength below 100%, or step back from 6 to 12 inches.

Read the precautions before ordering. Standard shipping to the US, UK and Germany is free. 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. Follow each device's manual for session length, and speak to a doctor or dermatologist before starting if you have a skin condition or take regular medicine.