Red Light Therapy for Swelling: What the Research Shows

Red light therapy for swelling has its clearest support after surgery and injury: reviews of wisdom tooth surgery trials found less facial swelling around day 2, and in a small ankle sprain trial, red LED light added to first aid brought swelling down faster than a switched-off device. Most of this research used clinic lasers or lamps alongside standard care, so light fits as an add-on, not a replacement. Below: the studies, sprains, surgery, swollen legs, puffy faces, warning signs and panel set-up.

Key takeaways

• A 2023 review of 33 randomised trials with 1,347 people found less facial swelling on day 2 after wisdom tooth surgery with light than without, at low certainty. Lacerda-Santos, 2023
• In a 2015 review of 6 wisdom tooth trials, light given only on the skin outside the mouth reduced swelling on days 1 to 3. He, 2015
• In a 2018 trial of 40 people with grade II ankle sprains, 627 nm red LED light added to first aid reduced swelling more than a switched-off LED on days 3 and 6. Prianti, 2018
• A 2023 review of jaw surgery trials with 205 patients found swelling 4.27 mm lower with laser light between 5 days and 2 weeks after the operation. Passos, 2023
• The NHS says swelling in one ankle, foot or leg with no known cause needs urgent advice from a GP or 111. NHS

Does red light therapy reduce swelling?

For swelling after surgery or a sprain, the trials point to yes: light reduced swelling after wisdom tooth, jaw, nose and knee surgery, and after ankle sprains. The effect was clearest in the first days, with light given alongside standard care.

Study	Who	Light	Swelling finding
Lacerda-Santos, 2023	33 trials, 1,347 people, wisdom teeth	Mostly clinic lasers	Less on day 2, low certainty
Vianna Camolesi, 2024	22 studies, 989 people, wisdom teeth	Infrared laser did best	Less at 48 hours
Passos, 2023	205 people, jaw surgery	Low-level laser	4.27 mm less, 5 days to 2 weeks
Rhinoplasty LED trial, 2025	60 people, nose surgery	660 nm red LED	Less swelling and bruising, weeks 1 and 2
Chia, 2025	30 people, knee replacement	Near-infrared laser	Lower swelling readings by day 6
Prianti, 2018	40 people, ankle sprain	627 nm red LED	Fell more on days 3 and 6

The effect was strongest early: by day 7 after wisdom tooth surgery the difference was no longer clear, and a 2024 review of 6 ankle sprain trials found a clearer effect on pain than on swelling. Alayat, 2024

Which kinds of swelling has red light been studied for?

Light has been studied for local swelling after injury and surgery, which is part of the body's healing response. Fluid swelling from the heart, kidneys, liver, veins, medicines or pregnancy is a different problem and a question for a doctor.

Cleveland Clinic says oedema happens "when fluid builds up faster in parts of your body than it can drain out". Cleveland Clinic

• Injury and surgery: sprains, strains and operations, where the light trials sit.
• Everyday fluid: the NHS lists staying in one position too long, salty food, pregnancy and some medicines, such as some blood pressure medicines and steroids. NHS
• Medical causes: kidney, liver or heart problems, blood clots and infection need a diagnosis first.

Does red light reduce swelling after wisdom tooth removal?

Reviews of mostly clinic laser trials found less facial swelling around day 2 after wisdom tooth surgery, at low certainty. Light given only on the skin outside the mouth also reduced swelling on days 1 to 3.

A 2024 review favoured infrared laser inside and outside the mouth in one session straight after surgery. Vianna Camolesi, 2024

Many clinic trials put a probe inside the mouth. The 2015 review separated these from light on the cheek alone, and both reduced swelling. He, 2015

• Timing: the NHS says pain and swelling "should start to improve after 1 or 2 days" and can last about 2 weeks. NHS
• At home: only after your dentist agrees, and only on the skin of the cheek and jaw, never inside the mouth.
• Warning signs: swelling that is severe or getting worse, a bad taste or a high temperature means calling your dentist or 111.

The mask does not reach the jawline, so use the panel side-on to the jaw.

Ice or red light first for a swollen sprain or injury?

Ice, rest, compression and elevation come first for the first 2 to 3 days, with no heat. Light fits from about day 3, over intact skin, in a separate session from ice.

The NHS advises ice "for up to 20 minutes every 2 to 3 hours" and warns that heat packs and hot baths can increase swelling early on. NHS

• Red LED: in the 2018 trial, 627 nm light over 6 days was added to first aid, and swelling measured by limb volume fell more than with a switched-off LED. Prianti, 2018
• Light lamp: in 50 adults, a broad-spectrum light lamp daily for 5 days with cold therapy gave the largest swelling improvement, "preliminary evidence" in the authors' words. Stasinopoulos, 2017

Keep compression and elevation going while swelling is visible, and let skin return to normal temperature after ice before light. Never remove a cast, splint or brace for light unless your doctor or physio agrees. Our guides to a sprained ankle and to injuries in general give the day-by-day plan.

Can red light ease swelling after knee replacement or nose surgery?

Small clinic trials found less swelling with light after knee replacement, nose surgery and jaw surgery, starting within a day or so of the operation. At home, light waits until the incision has fully closed and your surgeon agrees.

In a non-blinded trial of 30 people after knee replacement, laser light daily from day 1 to day 5 was added to standard care. Chia, 2025 By day 6, swelling readings were significantly lower, and the 2-minute walk figures were 27 metres for the light group against 16 metres for controls.

After nose surgery, 660 nm red LED light for 10 minutes, three times a day for 14 days, reduced swelling and bruising more than control in 60 people. Rhinoplasty LED trial, 2025 No adverse effects were reported.

Never use light over stitches, staples, dressings or drain sites, and ask your surgeon first about metal implants. Our guide to red light therapy after surgery covers start times and gentle first settings.

How does red light calm inflammation, and can more light make swelling worse?

In stressed or inflamed cells, light lowers inflammatory signals, mostly shown in cell and animal studies. The dose follows a curve, so more light is not better, and early heat can add to swelling.

A 2017 review states: "One of the most reproducible effects of PBM is an overall reduction in inflammation." Hamblin, 2017 It describes light absorbed by cytochrome c oxidase in the mitochondria and immune cells shifting away from an inflammatory state.

In 19 of 22 controlled lab studies, mostly in animals, light reduced inflammatory markers and oedema in a dose-dependent way. Bjordal, 2006 The 2017 review describes "a pronounced biphasic dose response": low doses stimulate, high doses inhibit. The panel's surface stays at or below 40°C, and skin should feel warm, never hot. See red light therapy for pain and inflammation for more.

Is red light useful for swollen legs and ankles at the end of the day?

For everyday leg swelling, raising your legs and gentle walking come first. A panel session at 12 inches can sit in an evening routine alongside them, but one swollen leg, or a leg that is red, hot or painful, needs a doctor first.

The NHS advises: "raise your legs or the swollen area on a chair or pillows when you can". NHS Our guide to red light therapy for lymphatic drainage covers the evening routine: 10 to 15 minutes per area at 12 inches, 2 to 3 times a week to start.

Lymphoedema needs a specialist service first, with compression garments, skin care and movement. NHS In arm lymphoedema after breast cancer, a review of clinic laser trials found less arm swelling than sham in the short term, as an addition to specialist care. Baxter, 2017

Can a red light mask reduce a puffy face in the morning?

Morning puffiness is often fluid that settles overnight and eases with time upright, and a cool compress is the usual first step. A mask session can follow as part of a morning skin routine, which is what the mask is built for, rather than as a de-puffing tool.

Mayo Clinic links puffy lower lids to fluid retention on waking or after a salty meal, and says cool compresses "can help improve their appearance". Mayo Clinic

• Order: cool compress, gentle facial massage, then the mask in the red mode on clean, dry skin.
• Eyes: the shell has an eye opening with no diodes over the eyes; keep your eyes closed.
• After facial surgery: only once healed and your surgeon agrees, starting with the red mode at 50% for 5 to 10 minutes every other day.

Swelling under one eye only, or puffiness that lasts all day, is worth a doctor's visit. Sudden allergic swelling of the face or mouth is "a medical emergency", says Cleveland Clinic. Cleveland Clinic

What settings did the wisdom tooth, sprain and surgery trials use?

The 2024 dental review favoured a clinic laser session straight after surgery, while the sprain and nose surgery trials gave light daily for 6 to 14 days. The two red LED trials used 627 and 660 nm on the skin.

Study	Light	Dose or time	Sessions	Where
Rhinoplasty LED trial, 2025	660 nm red LED	10 minutes	3 a day for 14 days	Skin of the face
Prianti, 2018, ankle sprain	627 nm red LED	10 J/cm²	Daily for 6 days, with first aid	Skin over the ankle
Chia, 2025, knee replacement	Near-infrared laser	Not given in the summary	Daily, days 1 to 5	Over the knee

Trial doses do not convert into panel minutes; what carries over is light on bare skin over the area, in regular sessions alongside first aid or post-operative care.

Which swelling, such as a swollen calf, needs a doctor before any light?

Swelling in one leg with no clear cause, swelling that is red or hot, and swelling after surgery that is getting worse all need a doctor first. Swelling with shortness of breath or chest pain is an emergency.

• One calf or thigh: throbbing pain, swelling and red or darkened skin can mean a blood clot; get urgent advice from a GP or 111. NHS
• Red or hot: the NHS lists swelling where "the swollen area is red or feels hot to the touch", a high temperature, or very sudden swelling. NHS
• Emergency: call 999 if you are short of breath, your chest feels tight, heavy or painful, or you cough up blood.
• After an injury: a crack heard at the time, a misshapen joint, numbness, or blue or cold skin means A&E. NHS

The NHS lists pregnancy and thyroid problems among causes of swelling, and both are on our do-not-use list. See red light therapy while pregnant.

Ibuprofen and naproxen, often taken for painful swelling, can make skin more sensitive to light. Our precautions rule out use with photosensitising medication, so anyone taking a medicine should check with their pharmacist or doctor before using the device.

How do you use red light therapy for swelling on an ankle or knee with a Kivorla panel?

From about day 3 after an injury, or once your surgeon agrees, sit with bare skin about 6 inches from the panel, goggles on, and run red and near-infrared for 10 to 15 minutes per area, 3 to 5 times a week. For general leg puffiness, 12 inches and 2 to 3 sessions a week is enough to start.

The 9-Spectrum Red Light Therapy Panel carries 480, 590, 630, 660, 670, 810, 830, 850 and 1060 nm, each dimmable 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.
• Distance: about 6 inches for an ankle, knee, wrist or elbow; about 12 inches for a thigh or both lower legs.
• Channels: 630 to 670 nm and 810 to 850 nm on; 1060 nm optional; 480 and 590 nm off; pulse off.
• Timer: 10 to 15 minutes per area; if no time is set, the panel stops at 5 minutes.
• Eyes: goggles on, eyes closed, even at knee height. For the jaw, sit side-on, never facing the panel.
• Tracking: tape-measure the same spot at the same time of day, note pain out of 10, and review after 2 to 3 weeks.

To stay closer to the modest doses in the trials, start with a shorter timer (it begins at 1 minute), turn the channels down from 100%, or step back to 12 inches. With reduced feeling in the feet, check with a clinician first. Leave at least 6 hours between 30-minute sessions. The controller and goggles are included.

For the face, the 4-Wavelength Red Light Therapy Mask has a red mode of 665 nm with 850 and 1064 nm near-infrared. The manual allows 10-minute sessions up to 4 times a week at high brightness, or 15 minutes up to 3 times a week, never more than 20 minutes a day.

Do not use the panel if you are pregnant, breastfeeding or preparing for pregnancy, have epilepsy, a thyroid condition or Fitzpatrick skin type V or VI, or have had sunburn on your body in the past 2 weeks. Never use either device over broken skin.

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 swelling or its causes. See a doctor for swelling in one leg, swelling that is red, hot or sudden, or swelling after surgery that is getting worse, and keep following your doctor's, dentist's or surgeon's care plan.