Red Light Therapy for Cold Sores: Does It Help Them Heal?
Red and near-infrared light can help a cold sore heal a little faster. Pooled across trials, sores treated with light healed about a day sooner, and two trials that treated the lip between outbreaks found cold sores came back far less often. The trials used small lasers or handheld devices held on or near the lip, between 650 and 1072 nm, not face masks, and most of them were small. Light does not remove the virus, so antiviral creams and tablets stay the first choice, and light is best thought of as something to use alongside them. Because a burst cold sore is broken skin and the virus spreads easily, any light device should only go on intact skin, and a face mask should never be shared during an outbreak. Below are the studies, the timing that was used, and what that means for a mask or panel at home.
Does red light therapy help cold sores?
The trials say it helps a little. Light-treated sores healed about 1.2 to 1.4 days faster than untreated or antiviral-treated ones.
A 2022 meta-analysis in Lasers in Medical Science pooled eight trials with 928 people and found healing 1.37 days faster with light. Barros 2022. A 2025 meta-analysis compared light directly with antiviral medicines such as aciclovir and valaciclovir in six randomised trials: light-treated sores healed 1.22 days sooner and hurt less on days two and three. Yang 2025. A 2018 systematic review of LED trials across dermatology gave herpes simplex a grade B recommendation, the same grade as acne. Jagdeo 2018. The reviewers asked for larger, better-blinded trials, and most trials were small, so treat a day faster as a possible benefit, not a promise.
What do the cold sore studies show?
Every trial below found something in favour of light. They used lasers or small handheld devices aimed at the lip.
| Study | Light and schedule | What they found |
|---|---|---|
| Dougal and Lee 2013, 87 people, against an identical-looking placebo device | 1072 nm near-infrared, 3 minutes three times a day for 2 days, on an active sore | Median healing 129 hours against 177 hours with placebo, about two days sooner |
| Honarmand 2017, 60 people, light against aciclovir cream against a switched-off laser | 870 nm laser held 6 to 8 mm from the sore, once a day, starting within 36 hours | Recovery in 2.2 days with light, 3.4 with aciclovir cream, 4.3 with the sham; pain also shorter |
| Seyyedi 2024, a small group on aciclovir, double-blind against a sham laser | 940 nm, a single session 24 to 48 hours after the sore appeared | Healing in 8.7 days against 10.5 with aciclovir alone; less pain on days 2 and 3 |
| Schindl and Neumann 1999, 48 people, double-blind against a placebo laser | 690 nm, 10 daily sessions over two weeks, given between outbreaks at the usual site | Median time to the next cold sore 37.5 weeks against 3 weeks with placebo |
| Zanella 2022, 158 people, against placebo, followed for two years | 808 nm over the lips, 10 sessions then 5 more six months later, between outbreaks | About 1 cold sore a year with the lower dose against 2.7 a year with placebo |
Sources: Dougal and Lee, Honarmand, Seyyedi, Schindl and Neumann, Zanella. The trials that reported on safety found no side effects from the light.
Can red light stop cold sores coming back?
Two trials suggest it can space them out, when the light is given to the usual spot while there is no sore.
In the 1999 trial, the gap before the next outbreak stretched from a median of 3 weeks to 37.5 weeks after ten daily sessions. In the 2022 trial, people treated with the lower dose had about one cold sore a year over two years, against nearly three with placebo. That second trial had a twist worth knowing: a group given double the light did well at first, then lost the effect over time. In that trial, more light was not better. Neither trial removed the virus, and no light treatment does.
Red light or infrared for cold sores?
Both have worked. Trials used everything from 650 nm red to 1072 nm near-infrared.
Handheld cold sore devices mostly combine 660 nm red with 850 nm near-infrared, and one long-established type uses 1072 nm alone. The prevention trials used 690 nm red and 808 nm near-infrared; the active-sore trials above used near-infrared at 870, 940 and 1072 nm. Blue light is a different story: there is no cold sore evidence for it.
When should you use light: at the tingle, the blister or between outbreaks?
The trials used light early, within the first day or two, or between outbreaks. Once the blister has burst, the skin is broken.
A cold sore usually starts with tingling, itching or burning; blisters appear within about 48 hours, then burst and crust, and most clear within 10 days. NHS. The active-sore trials started early, within the first day or two where they reported timing, and one study dosed at the tingling stage. The prevention trials treated the usual site on clear skin. For home use, the skin is intact at two points: the tingle, before it breaks, and the weeks between outbreaks. Kivorla's precautions rule out using the devices on broken skin, so leave a weeping or crusting sore alone and let your antiviral do the work.
Can you use a red light mask when you have a cold sore?
Not over an open sore, and never share it while you have one. Between outbreaks, on clear skin, there is no reason to stop your usual sessions.
The Kivorla mask's silicone shell covers the lower face, including the skin around the mouth, so it touches the area where cold sores appear. The NHS says cold sores are contagious from the first tingle until they have fully healed, and that they spread easily to other people and other parts of your own body. The Mayo Clinic warns the virus can reach the eyes. Mayo Clinic. Dermatologists advise not sharing anything that touches the lips, such as cups, towels and lip balm. AAD. A face mask belongs on that list. In practice:
- Pause the mask once a blister forms, and restart when the sore has fully healed.
- Do not lend it to anyone during an outbreak.
- Clean the inner shell as the manual describes after each session, and wash your hands after touching your lip.
- Keep your fingers away from your eyes after touching the sore.
The mask's red mode wavelengths, 665 nm red with 850 and 1064 nm near-infrared, sit inside the range the trials used. That is a fact about wavelengths, not a result: the mask has not been tested on cold sores, and the trials used one to three sessions a day, while the mask's manual allows up to four sessions a week and 20 minutes in a day. Do not use the blue mode for cold sores.
Can red light therapy trigger a cold sore?
Red and near-infrared light are not the kind of light that sets them off. The light that triggers cold sores is ultraviolet, from strong sun or sunbeds, and red and near-infrared light contain no UV.
The NHS lists sunbeds and sun among common triggers and recommends a sunblock lip balm of SPF 15 or above. Stress is another common trigger. If you notice a sore every time you do something, keep a short note of it; that tells you more than any general list.
Red light therapy or aciclovir?
Use the antiviral. Light can go alongside it, and in one double-blind trial the combination healed faster than aciclovir alone.
Antiviral creams work best applied at the first tingle; tablets prescribed by a doctor generally work better than creams. Mayo Clinic. People who get frequent outbreaks can ask about taking an antiviral daily to prevent them. AAD. In the 2024 trial, adding a single light session to aciclovir cut healing from 10.5 to 8.7 days. That is the sensible way to think about it: medicine first, light as an extra.
When should you see a doctor about a cold sore?
If it has not started to heal within 10 days, if it is very large or painful, if your eyes feel sore or gritty, or if your immune system is weakened.
Those are the NHS and Mayo Clinic thresholds. Also get advice if you have eczema and a cold sore, since the virus can spread across eczema skin, and keep away from newborn babies while you have one. Never kiss a baby with an active cold sore.
Using Kivorla devices with a cold sore in mind
Neither Kivorla device is designed or tested for cold sores. What you can do is use them in a way that fits what the research and the hygiene advice say.
With the 4-Wavelength Red Light Therapy Mask, keep using the red mode as part of your normal skin routine on clear skin, pause it from blister to full healing, and keep it to yourself. The 9-Spectrum Red Light Therapy Panel lets you set red and near-infrared channels on their own and turn the blue off, with goggles on whenever you face it. For the skin uses each device is built for, see red light therapy for face, and for safety in general, is red light therapy safe.
Read the precautions before ordering, since returns are accepted within 30 days, less a 10% restocking fee if the device is unopened with its seals intact, or 20% if it is opened but undamaged and complete. Standard shipping to the US, UK and Germany is free.
Kivorla devices are general wellness devices, not medical devices, and are not a treatment for cold sores or herpes. Speak to a pharmacist or doctor about antiviral treatment, and do not use a light device on broken skin.