Red light therapy shows genuine promise for shingles, particularly for reducing pain and speeding the healing of skin lesions, though the evidence base remains small and somewhat uneven. Most of the published research involves low-level laser therapy or LED devices emitting red to near-infrared wavelengths, applied alongside standard antiviral medication rather than replacing it. The strongest signals come from its potential to prevent or treat postherpetic neuralgia, the stubborn nerve pain that can persist long after the rash clears. Still, the studies that exist tend to be small pilot trials with significant variation in how therapy is delivered, and no large randomized controlled trial has settled the question definitively.
Why Light in This Wavelength Range Affects Tissue at All
Red and near-infrared light, roughly in the 600 to 900 nanometer range, penetrates skin more deeply than shorter wavelengths like blue or green light. At a cellular level, components of the mitochondrial electron transport chain are sensitive to these wavelengths. When red or near-infrared photons reach mitochondria, they stimulate increased production of ATP, the cell’s primary energy currency, and cause brief surges in reactive oxygen species that trigger downstream signaling cascades involved in repair and inflammation control.1PubMed Central. Low-intensity light therapy: exploring the role of redox mechanisms That is a simplified version of a process researchers still have not fully mapped, but it helps explain why shining a particular color of light on damaged tissue could plausibly do something useful.
For shingles specifically, the nerve-related effects matter as much as the skin-healing ones. The varicella-zoster virus reactivates from dormant nerve tissue and travels along nerve fibers to the skin, causing both the characteristic blistering rash and the often severe nerve pain. Animal studies on peripheral nerve injuries have found that near-infrared LED irradiation promotes nerve regeneration and increases antioxidant activity in the surrounding fluid.2PubMed. Effect of near-infrared light-emitting diodes on nerve regeneration More recent work using 807-nanometer LEDs on sciatic nerve injuries in animals showed measurable improvements in myelin sheath thickness, nerve diameter, and axon diameter.3PubMed. The effect of 807-nm light-emitting diode photobiomodulation on peripheral nerve injury These are not shingles studies, but they establish that photobiomodulation can meaningfully affect damaged nerves, which is the core issue behind shingles pain.
Evidence During the Acute Rash Phase
A handful of clinical studies have tested red or near-infrared light therapy during an active shingles outbreak, always as an add-on to antiviral drugs like acyclovir or famciclovir rather than a standalone treatment. The results are consistently encouraging, if not yet overwhelming.
One pilot study focused on herpes zoster ophthalmicus, the form of shingles affecting the eye area, which is particularly painful and carries risks to vision. Patients who received 830-nanometer LED therapy alongside famciclovir healed in about 13 days on average, compared with roughly 16 days for those on the antiviral alone. That difference was statistically significant. Pain scores also improved faster in the LED group starting around day four, though the gap between groups on pain was marginal and did not reach conventional statistical significance.4PubMed Central. The Effects of 830 nm Light-Emitting Diode Therapy on Acute Herpes Zoster Ophthalmicus: A Pilot Study That pattern, clearer benefits for wound healing than for pain during the acute phase, has shown up in other small studies too.
A single-center prospective study compared three groups of hospitalized shingles patients: one receiving acyclovir alone, one adding red-light LED therapy, and one adding golden-light (a slightly different wavelength) LED therapy. Both light groups saw shorter times for the blisters to stop spreading, crust over, and shed their scabs compared to the drug-only group. Interestingly, the golden-light group healed somewhat faster than the red-light group on the crusting and shedding measures, with total effective rates of about 89% for golden light, 78% for red light, and 72% for the control.5PubMed. Clinical efficacy of LED golden light combined with acyclovir in the treatment of herpes zoster: a single-center prospective study With only 18 patients per group, these numbers need to be taken as signals rather than settled facts, but they do suggest the light therapy is contributing something real beyond the antiviral alone.
A case report of a younger patient treated with antimicrobial photodynamic therapy combined with low-intensity laser irradiation found the approach effective and safe, with healing of the lesion area and improvement of symptoms.6PubMed. Antimicrobial Photodynamic Therapy Used as First Choice to Treat Herpes Zoster Virus Infection in Younger Patient: A Case Report Case reports sit at the bottom of the evidence hierarchy, but this one is worth noting because it used photodynamic therapy as a first-line treatment, suggesting some clinicians are confident enough in the approach to lead with it in selected patients.
Can It Prevent Postherpetic Neuralgia?
This is where the evidence gets especially interesting. Postherpetic neuralgia, the nerve pain that lingers for months or even years after shingles clears, is the complication most patients dread. It affects a substantial minority of shingles patients and is notoriously difficult to treat once established. If light therapy during the acute phase could reduce the risk of developing it, that would be a significant clinical win.
A study published in the Journal of the American Academy of Dermatology examined exactly this question. Patients who received low-level laser therapy during their acute shingles episode had dramatically lower odds of developing postherpetic neuralgia at one, three, and six months afterward. After adjusting for age, sex, and antiviral use, the odds ratio for developing postherpetic neuralgia at one month was 0.21 in the laser-treated group versus the control group. At three months it was 0.112, and at six months 0.123.7Journal of the American Academy of Dermatology. Early application of low-level laser may reduce the incidence of postherpetic neuralgia In plain terms, patients who got laser therapy early on were roughly five to nine times less likely to still have nerve pain months later.
Those are striking numbers, and the fact that they held across multiple time points and after adjusting for confounders lends them some credibility. But this was a single study, not a meta-analysis of twenty trials, and the intervention was a specific clinical laser protocol rather than a consumer LED panel used at home. The finding deserves serious attention and replication, not uncritical acceptance.
Treating Postherpetic Neuralgia That Has Already Developed
For patients who already have established postherpetic neuralgia, the picture is also favorable, though again based on limited data. Several small studies have tested low-level laser or red-light therapy on patients suffering persistent nerve pain after shingles, and the results are consistently positive across all of them.
In one pilot study of 15 patients with postherpetic neuralgia, 11 reached a pain score of zero by the end of treatment despite starting with moderate to severe pain. Three others dropped to mild intensity, and just one remained at a moderate level. Perhaps more impressively, none of the patients reported recurrence of pain in the months following therapy.8PubMed. Role of low-level laser therapy in post-herpetic neuralgia: a pilot study Those results look almost too good, and with only 15 patients and no control group, they should be interpreted cautiously. But the durability of the pain relief, months without recurrence, is noteworthy because postherpetic neuralgia is famously persistent.
A larger study evaluated 31 patients with severe or persistent postherpetic neuralgia who were admitted to an inpatient pain clinic. They received two laser therapy sessions daily, each lasting 10 to 20 minutes. Average pain scores dropped from 7 out of 10 at admission to 3 at discharge. Before admission, none of the patients had mild pain or were pain-free; by the final assessment, 23 of the 31 fell into those categories.9Laser Therapy. THE RÔLE OF LASER THERAPY IN INTENSIVE PAIN MANAGEMENT OF POSTHERPETIC NEURALGIA The inpatient setting with twice-daily sessions is far more intensive than what most people could replicate at home, but the magnitude of pain reduction was considerable for a condition where even modest improvement matters to patients.
A study comparing red light irradiation plus gabapentin against gabapentin alone in 90 postherpetic neuralgia patients found that the combination group had significantly lower pain scores after treatment.10Tianjin Medical Journal. The effect of red light irradiation therapy on postherpetic neuralgia and its effect on life quality of patients That last study is worth flagging because gabapentin is one of the standard first-line drugs for postherpetic neuralgia, and finding that light therapy adds something on top of it suggests the two work through different pathways.
How Solid Is the Overall Evidence?
The direction of the evidence is remarkably consistent: across acute shingles, postherpetic neuralgia prevention, and postherpetic neuralgia treatment, studies show benefit. But the quality and quantity of that evidence are not yet where a skeptic would want them to be.
A systematic review and meta-analysis on low-level laser therapy for postherpetic neuralgia found substantial heterogeneity among the included studies, with an I-squared value of 93%, meaning the results varied enormously from study to study.11PubMed Central. Low-Level Laser Therapy in Post-Herpetic Neuralgia: A Systematic Review and Meta-Analysis That level of variation is almost certainly driven by differences in study design, patient selection, and treatment protocols. Different studies use different wavelengths (630, 780, 830, 904 nanometers and others), different power densities, different session lengths, and different numbers of treatments. Some use lasers, others use LEDs. Some treat during the acute rash, others treat established neuralgia months or years later. Grouping all of these together into one meta-analysis inevitably produces messy results.
The practical upshot is that we can be fairly confident light therapy does something helpful for shingles-related pain and healing, but we cannot yet say with precision what wavelength, dose, or protocol is optimal. This is a field where the signal is clear but the tuning is still rough.
Lasers Versus LED Panels
Most of the clinical studies on shingles used either clinical-grade low-level lasers or medical LED devices, and the distinction matters if you are considering trying this at home. Clinical lasers deliver coherent, focused light at a specific wavelength with precisely controlled power. LED panels deliver a broader spread of light across a wider area, often mixing wavelengths. Some of the shingles studies specifically used LEDs, including the herpes zoster ophthalmicus trial with its 830-nanometer LED and the golden-light study mentioned earlier, so LED-based therapy is not inherently inferior for this purpose.
A review comparing lasers and LEDs for photobiomodulation broadly concluded that both can produce therapeutic effects, though the optimal parameters differ between the two technologies.12PubMed Central. Photobiomodulation: Lasers vs Light Emitting Diodes? The consumer LED devices marketed for skin health or pain relief are generally lower-powered than what clinics use, which means you would typically need longer exposure times to deliver a comparable total energy dose. Whether that translates into the same clinical benefit is genuinely unknown: the studies did not test consumer-grade devices, and extrapolating from clinical hardware to something you buy online is a leap.
If you are considering a home device, looking for one that specifies its wavelength (ideally in the 630 to 850 nanometer range, matching the wavelengths used in the shingles literature) and its power density in milliwatts per square centimeter is more useful than relying on marketing claims. The total energy delivered to the tissue, a function of power density and time, is what drives the biological response.
Practical Considerations and Safety
Red light therapy has an excellent general safety profile. The wavelengths used do not cause DNA damage the way ultraviolet light does, and the energy levels involved in photobiomodulation are far below what would cause thermal burns. Side effects in the shingles studies were minimal to nonexistent. That said, there are practical issues worth considering.
Shingles blisters are open or semi-open wounds teeming with live virus. Pressing a device directly against active lesions raises hygiene concerns, both for contaminating the device and for irritating fragile skin. Clinical protocols typically hold the light source slightly above the skin rather than making direct contact, and some use transparent barriers. If you are using a home device on an active rash, keeping it clean and maintaining a small gap between the device and your skin is sensible.
Timing seems to matter. The postherpetic neuralgia prevention study found its dramatic results specifically when laser therapy was started during the acute phase, not weeks later. That aligns with the general principle in shingles treatment: early intervention produces better outcomes. If you are going to try light therapy alongside your antiviral medication, starting early in the course of the rash is likely more useful than waiting.
None of the published research supports using red light therapy instead of antiviral drugs. Every clinical study on acute shingles tested light therapy as an add-on to standard antiviral treatment. Skipping antivirals in favor of a light panel would be ignoring the strongest evidence base in shingles treatment. The question is not “red light therapy or antivirals” but “antivirals alone or antivirals plus light therapy.”
Why Shingles Pain Is Especially Suited to This Approach
Not every type of pain responds equally well to photobiomodulation, and there are reasons to think shingles-related pain is a particularly good match. The pain of shingles is neuropathic, meaning it originates from damaged or dysfunctional nerves rather than from ongoing tissue injury. The varicella-zoster virus literally destroys nerve tissue as it reactivates and travels along nerve fibers. Postherpetic neuralgia happens when that nerve damage persists even after the viral infection resolves.
The animal studies on nerve regeneration suggest that red and near-infrared light can support the regrowth and repair of damaged peripheral nerves through increased antioxidant activity and improved mitochondrial function.2PubMed. Effect of near-infrared light-emitting diodes on nerve regeneration If that mechanism translates to human shingles patients, it would explain both the acute pain relief and the prevention of postherpetic neuralgia: you are not just masking pain signals but actually helping the damaged nerves repair themselves. That is a fundamentally different mechanism from painkillers or nerve-blocking medications, which is why combining light therapy with drugs like gabapentin might produce additive benefits.
The dermatomal distribution of shingles, where the rash and pain follow a specific nerve pathway and are usually confined to a band on one side of the body, also makes it logistically easier to treat with light. You know exactly where the affected nerve runs, and the skin surface directly over that nerve path is accessible. Conditions involving deep-seated or widely distributed nerve damage would be harder to treat with a light that penetrates only a few centimeters.
What the Wavelength Differences Actually Mean
The shingles studies do not all use the same wavelength, and this is not just a technicality. Red light in the 630-nanometer range has shallower tissue penetration than near-infrared at 830 or 850 nanometers. The shallower wavelengths may be better at treating the superficial skin lesions, which fits with the finding that golden-light and red-light LEDs helped blisters heal faster.5PubMed. Clinical efficacy of LED golden light combined with acyclovir in the treatment of herpes zoster: a single-center prospective study The deeper-penetrating near-infrared wavelengths are more likely to reach the nerve tissue beneath the skin where the real damage is occurring, which may explain why the 830-nanometer LED study saw clearer benefits for healing time than for pain in the acute phase, and why the postherpetic neuralgia studies, which specifically target nerve-level pathology, tend to use near-infrared wavelengths.
Some researchers and clinicians advocate using a combination of wavelengths to address both the surface lesions and the deeper nerve damage simultaneously. This is plausible based on the physics but has not been directly tested in a controlled trial on shingles patients. Multi-wavelength LED panels that emit both red and near-infrared are widely available in the consumer market, which at least means the hardware exists for someone inclined to try this approach at home, though the dose delivered by consumer panels remains the uncertain variable.
The honest summary is that red light therapy, broadly defined, looks promising for shingles at every stage: it may speed up rash healing during the acute phase, substantially reduce the risk of developing chronic nerve pain, and alleviate that pain once it has set in. The biological mechanisms are plausible, the clinical results point consistently in the right direction, and the safety profile is excellent. What is missing is the kind of large, well-standardized trial that would move this from “promising” to “recommended,” along with clear guidance on exactly which device settings produce the best outcomes. For someone currently dealing with shingles or postherpetic neuralgia who is already on appropriate medical treatment, adding light therapy involves very little risk and a reasonable chance of meaningful benefit.