I’ve owned my red light panel for six years, and for about five of them I ignored the little option labeled “pulsing.” I assumed it was a gimmick. Then a friend at my gym asked whether she should pay an extra $200 for a device with pulsing, and I realized I had no idea what to tell her.
So I went looking. Here’s the short version: pulsed light does appear to work better than continuous light for some things. But almost all of that evidence comes from lasers, not from the LED panels most of us actually own.
That gap matters more than any marketing page will admit. Let’s walk through it.
Key Learnings
- Pulsed light outperformed continuous light in six of nine head-to-head studies, mostly for wound healing, pain, and stroke recovery
- Nearly all of that research used lasers. Most home devices use LEDs, which behave differently
- The pulse frequency seems to matter more than whether a device pulses at all. Around 10 Hz keeps showing up as the sweet spot
- One human trial in exercising adults found pulsed light beat continuous light for muscle recovery
- Pulsing appears to be as safe as continuous light, but more light is not automatically better
What Is Red Light Therapy Pulsing?
Red light therapy uses low-level light, typically between 630 and 700 nanometers (nm), to trigger changes in your cells. Researchers have studied it for skin rejuvenation, collagen production, and improvements in skin tone and texture [1].
When the light stays on for your whole session, usually 5 to 20 minutes, that’s continuous wave therapy.
Pulsing means the light switches on and off in a deliberate, repeating pattern. We measure that rhythm in Hertz (Hz), which simply counts how many on-off cycles happen per second. A device pulsing at 10 Hz flickers on and off ten times every second.
Most pulsed protocols use a 50:50 cycle, meaning the light is on half the time and off half the time. Here’s a detail worth getting right, because a lot of articles muddle it: that cycle cuts the total energy your skin receives over the session roughly in half. It does not make each individual pulse weaker. The light during each burst is just as strong, and in pulsed lasers it’s often far stronger.
That distinction turns out to be the whole argument for pulsing.
Pulsing Is Not the Same as Flickering
Cheap devices sometimes flicker, and that’s a completely different thing.
Flickering happens by accident, as a side effect of alternating current (AC) power. It’s irregular and nobody designed it. Pulsing is deliberate, precisely timed, and set to a specific frequency.
If you’re shopping for a panel, low flicker is worth checking regardless of whether you care about pulsing.
Why Most Pulsing Research Doesn’t Transfer to Your Panel
Here’s the caveat that shapes everything below, so I want to put it up front rather than bury it.
The studies showing pulsed light beating continuous light almost all used lasers. Most at-home red light devices use LEDs. These two light sources are not interchangeable.
Laser light is coherent, meaning its waves travel in tight formation, all aligned and moving in lockstep. LED light is incoherent: it scatters outward in many directions at once. Lasers also generate meaningful heat, while LEDs stay comparatively cool.
So when a study finds that a pulsed laser penetrated deeper or healed faster, you can’t assume your LED panel does the same thing when you press its pulse button. The mechanism behind the advantage may not survive the switch.
Pulsing vs. Continuous: What the Research Shows
The most thorough comparison comes from a review by researchers at the Wellman Center for Photomedicine at Massachusetts General Hospital and Harvard Medical School, led by Michael Hamblin, one of the field’s most-cited scientists [2].
His team found nine studies that directly pitted pulsed light against continuous light. Six favored pulsed. One found them equal. Two favored continuous, though in those cases pulsed light still outperformed a placebo.
The wins clustered around wound healing, pain relief, and ischemic stroke, which is the type caused by a blocked blood vessel in the brain.
The team also explained why pulsing might help. Pulsed lasers reach greater depths because each burst carries higher peak power, and the off-periods let tissue cool so that extra power doesn’t cause thermal damage. Pulsed light produced no measurable temperature change in the treated area at the same delivered energy density.
They were careful about their conclusion, though. As the authors put it, “much more research remains to be done at both basic science and clinical levels” before pulsing’s role becomes clear.
Muscle Recovery & Soreness
This is the section I’d have wanted when my friend asked, and it’s the strongest human evidence I found.
Researchers ran a randomized, double-blind, placebo-controlled trial with 40 healthy untrained men [3]. Each participant received a single 180-joule dose to the quadriceps before an eccentric exercise protocol designed to trash their legs. The four groups got either a placebo, a high-powered continuous device, a low-powered continuous device, or a low-powered pulsed device.
The low-powered pulsed group won on every measure. They held onto more strength, reported less delayed-onset muscle soreness at every time point over the next 96 hours, and showed lower creatine kinase, a blood marker that rises when muscle tissue gets damaged.
The high-powered continuous device did worse than placebo on creatine kinase between 1 and 24 hours.
What this means for you: if you’re using red light for training recovery, this trial suggests pulsing may be worth switching on. It also suggests that buying the most powerful device you can find might backfire.
Wound Healing & Tissue Repair
In immunosuppressed rats with skin wounds, researchers compared an 810 nm laser at three settings: continuous, pulsed at 10 Hz, and pulsed at 100 Hz [4]. Same wavelength, same dose. Only the rhythm changed.
The 10 Hz group healed best. Wounds contracted faster, inflammation markers dropped further, and new blood vessel formation improved.
A separate study on rats with deep second-degree burns tested two doses of pulsed 890 nm light against an untreated control [5]. The higher dose, 11.7 J/cm², sped up wound closure from two weeks onward and significantly reduced Staphylococcus aureus in the wounds by day 28.
Worth noting: every laser group in this study was pulsed, so it tells us about dosing within pulsed light rather than pulsed versus continuous.
For LED devices specifically, a 2026 systematic review pooled six randomized trials on chronic lower-limb wounds [6]. LED therapy appeared to shrink wounds and improve blood flow, especially in diabetic foot ulcers. The reviewers graded the overall certainty of that evidence as very low, and one trial using a very high energy density showed no benefit at all.
Pain Management
Red light may ease pain, and researchers think its anti-inflammatory effects explain why. Light therapy reduces inflammatory signaling molecules like TNF-α and IL-6, and shifts immune cells toward a healing mode [7].
A 2021 review examined light therapy for fibromyalgia and other musculoskeletal pain [8]. Results were mixed: some trials found no advantage over placebo. The strongest was a 160-patient trial where light therapy, both alone and combined with exercise, produced the biggest reductions in pain.
One small human study offers an unusually clean comparison [9]. A patient with limited scleroderma, a connective tissue condition affecting the joints, received pulsed light on one elbow and continuous light on the other for 13 weeks. Both elbows improved. The pulsed side improved more.
That’s a single patient, so treat it as a hint rather than proof. But the design neatly removes the differences between people that muddy larger studies.
Skin & Anti-Aging
This is my own main use, so I went in hoping for a clear answer. I didn’t get one.
Continuous red light has solid support here. In a randomized controlled trial of 136 volunteers, 30 sessions over 15 weeks reduced skin roughness, increased collagen density on ultrasound imaging, and produced wrinkle improvements that blinded evaluators could see in photographs [1].
What I couldn’t find was a head-to-head skin trial pitting pulsed against continuous. Anyone claiming pulsing gives you better skin is extrapolating from wound-healing research, not citing a skin study.
If you’re mainly interested in the benefits of red light therapy for your face, the continuous protocols already have the evidence behind them. There’s no reason to feel you’re missing out.
Where Continuous Wins
Pulsing isn’t a clean sweep, and I think it’s worth showing the results that cut the other way.
In a 2023 laboratory study on human gum tissue cells, researchers compared pulsed and continuous near-infrared light across several doses [10]. Continuous light at 5.2 J/cm² was the only setting that significantly increased cell migration. Pulsed didn’t manage it.
That was cells in a dish rather than people. Still, it’s a reminder that “pulsed is better” isn’t a universal rule.
The Frequency Matters More Than the Pulse
If you take one technical point from this article, make it this one.
In a study on mice with traumatic brain injuries, researchers tested 810 nm light in continuous mode, pulsed at 10 Hz, and pulsed at 100 Hz [11]. Everything else stayed identical: same wavelength, same power density, same 12-minute session, same total dose of 36 J/cm².
The 10 Hz group came out clearly ahead. Brain lesions were significantly smaller at 15 days and 4 weeks. Continuous and 100 Hz both helped, but less.
Notice that 10 Hz also won the rat wound-healing study above. Same frequency, different injury, different research team.
So a device that simply “has pulsing” tells you very little. A device that pulses at a frequency the research supports tells you something. Most manufacturers don’t publish their frequency, which is worth asking about before you pay a premium.
Is Pulsed Red Light Therapy Safe?
Red light therapy has a strong safety record. After decades of use, researchers describe an almost complete absence of reported side effects or adverse events [12]. Nothing suggests pulsing changes that.
The real catch isn’t a side effect. It’s that more is not better.
Light therapy follows what scientists call a biphasic dose response. Too little light does nothing. The right amount helps. Too much can reduce or cancel the benefit entirely [12]. That’s why the systematic review above found no effect in the trial using the highest energy density, and why the high-powered device in the athlete trial underperformed placebo on one marker.
Running longer sessions to “get more out of it” may leave you worse off than following the manufacturer’s schedule.
Two other things to keep in mind. Be skeptical of devices marketed for serious medical conditions. Light therapy does have well-established clinical uses, and one review calls oral mucositis, the painful mouth sores caused by chemotherapy and radiation, the single most effective indication for it [13]. But that’s a clinical treatment delivered by professionals, not a reason to trust a panel advertising cancer benefits.
And if you have a diagnosed condition, are pregnant, or take medication that increases light sensitivity, check with your doctor before starting.
So Should You Pay Extra for Pulsing?
Here’s where I landed, and what I told my friend.
If pulsing comes included on a device you already like, use it. The evidence leans mildly positive, particularly for muscle recovery and wound healing, and there’s no indication it does harm.
If pulsing costs a significant premium, I’d think twice. The advantage is best documented in lasers, and your panel probably uses LEDs. If the manufacturer won’t tell you the pulse frequency, you can’t even check whether it lands near the 10 Hz range the research favors.
My honest opinion: spend that money on verified wavelength, adequate irradiance, and low flicker instead. Those affect every session you’ll ever run. Pulsing is a maybe.
She kept her existing panel. So did I.
Final Thoughts
Pulsing is a genuinely interesting area of research, and it may turn out to matter a lot as LED-specific studies catch up. The National Institute on Aging has taken enough interest in light therapy for aging and age-related disease to convene a dedicated workshop on it [14], so the science here is expanding quickly.
For now, though, pulsing is a promising bonus feature rather than a reason to upgrade.
Have you tried the pulse setting on your device? I’d like to hear whether you noticed a difference, so let me know in the comments.
References
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3926176/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2933784/
- https://pubmed.ncbi.nlm.nih.gov/28319422/
- https://pubmed.ncbi.nlm.nih.gov/27861614/
- https://pubmed.ncbi.nlm.nih.gov/20860542/
- https://pubmed.ncbi.nlm.nih.gov/42315692/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5523874/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9980499/
- https://pubmed.ncbi.nlm.nih.gov/25393970/
- https://pubmed.ncbi.nlm.nih.gov/37254280/
- https://pubmed.ncbi.nlm.nih.gov/22028832/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3288797/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5946726/
- https://pubmed.ncbi.nlm.nih.gov/39826026/
