Short answer, before anything else: nobody has properly tested whether an LED panel helps a horse. One study has tried. It found no benefit. That is the entire direct evidence base, and any company telling you otherwise is describing hope rather than data.
We sell LED panels. We are still going to walk you through why the honest answer here is “we do not know,” because a horse owner spending four figures deserves the actual state of the research rather than a brochure.
The one LED study in horses, and what it found
Michanek and colleagues at the Swedish University of Agricultural Sciences ran the only equine trial we can find that used LEDs rather than a therapeutic laser. The design is genuinely good — better than most of the laser work:
- Eight healthy horses, each given a 2 cm circular skin wound on both sides of the neck
- One wound treated, the other left untreated, chosen at random — so every horse is its own control
- Blinded assessment, using digital photoplanimetry and ultrasound for swelling
- Red light at roughly 637 nm (2.3 mW/cm²) and near-infrared at roughly 956 nm (6.4 mW/cm²), daily across four treatment blocks over 25 days
Results: wound area did not differ on any day. Swelling did not differ on any day. And healing time was significantly longer in the treated wounds — 51.8 days versus 49.0 for the untreated controls (p = 0.03).
The authors concluded that the results “do not indicate any clinically relevant positive effect” of red and near-infrared light on equine wound healing compared with no treatment at all.
Two honest caveats, in both directions. The treated wounds healing slower is a small difference across a wide confidence interval and should not be read as light being harmful. But the irradiance used — 2.3 to 6.4 mW/cm² — is far below what a full-size panel delivers at treatment distance. This study tested a much weaker dose than a panel gives. It is still the only LED evidence in horses, and it is negative.
Does the laser evidence carry over?
This is the question that actually decides the matter, because the positive equine results all come from Class IV therapeutic lasers — devices running up to 15 W into a small spot. Our equine device guide lays those studies out in full.
The good news for panels is that coherence — the property that makes a laser a laser — does not appear to be the active ingredient. A 2026 systematic review screened 2,020 studies, included 16, and found that although laser showed quantitatively greater effects on some measures such as blood vessel density and type I collagen deposition, “both modalities show similar preclinical effects.” Cellular photoacceptors do not appear to care whether a photon arrived coherent. We cover this in more depth in LED vs laser devices.
So the gap between a 15 W laser and an LED panel is not really about the physics of the light. It is about how much energy reaches the tissue, and over what area. A laser concentrates a lot of power into a small spot for a short time. A panel spreads much less power over a large area for longer. Those can in principle deliver a similar dose in joules per square centimetre — and the biphasic dose curve (Huang et al. 2009) says dose is what matters.
In principle. In horses, nobody has run the study that would confirm it.
The part almost nobody mentions: the coat
Here is where equine treatment genuinely differs from human treatment, and where most of the marketing goes quiet. A human torso is bare skin. A horse has a coat, and the coat is not a minor variable.
Coat colour matters far more than coat length. A study of 47 dogs — 17 black, 15 brown, 15 white — measured how many photons actually made it through to tissue. Transmission fell significantly with increasing coat pigment (p < 0.001) and rose significantly when the area was shaved (p < 0.001). Coat length was not a significant predictor at all. It is the pigment absorbing the light, not the fibre length.
How much does dark pigment matter? In large animals specifically, a near-infrared spectroscopy study found that black hair covering and dark hooves prevented near-infrared light from penetrating enough to take a measurement at all, while non-pigmented hair was not a barrier. That is not a modest reduction. For that instrument, on those tissues, black hair stopped the light.
And clipping does more than you would guess. Twenty Thoroughbreds were treated over the carpal joint, half clipped and half not. The clipped group showed a lower rise in skin surface temperature but a greater increase in vein diameter. The authors concluded that clipping “increases photobiostimulation of the tissue, while reducing the photothermal effect.” In plain terms: on an unclipped coat more of your energy becomes heat at the surface, and less of it becomes the biological effect you were aiming for.
What this means in practice
- A dark bay or black horse is the hardest case. Published measurements suggest much of the near-infrared may not be getting past the coat. Any dose you calculated from the panel specification is optimistic.
- Clip the treatment area if the situation allows it. This is the single best-supported practical step on this page, and it is free.
- Grey and light-coated horses are the best case for light actually reaching tissue.
- Distance and time still follow the dose curve. More is not better past the peak — that is what biphasic means.
What would have to be true for panels to work in horses
Laying out the chain honestly, because each link is a place this could fail:
- Coherence is not required — reasonably supported by the LED-versus-laser literature
- Dose in J/cm² is the governing variable — well supported in human and cell work
- A panel can deliver a therapeutic dose at realistic standoff distance — plausible, not demonstrated in horses
- That dose survives the coat — doubtful on dark coats, untested on panels
- Enough reaches the target structure — untested for panels in horses
Links one and two are in decent shape. Links three, four and five are assumptions. A company that skips from link two to a testimonial is skipping the part that matters.
What we would actually tell you
If you are treating a horse for a diagnosed tendon or ligament injury and want the option with the most supporting evidence, that is currently a Class IV therapeutic laser applied by a veterinarian — not a panel, and not us. That is what the published trials used.
If you are treating back soreness or muscular stiffness, the strongest equine trial on record used low-level laser on 61 competing Quarter Horses and found significant reductions in back pain, muscle hypertonicity and trunk stiffness. Again: laser, applied clinically.
If you already own a panel and want to use it on a horse, clip the area, keep sessions within published dose ranges, expect less from a dark coat, and treat it as an adjunct to veterinary care rather than a substitute. Do not expect it to close a wound faster — that is the one thing that has been tested, and it did not.
And if a supplier shows you dramatic equine before-and-after photographs from a panel, ask which controlled trial those came from. We looked. As of this writing there is one, and it is the null result described above.
Common Questions
Do LED panels work on horses?
Nobody knows, and anyone claiming certainty is overstating. The single controlled trial using LEDs in horses tested wound healing and found no benefit. The positive equine results in the literature all used high-power Class IV lasers, which deliver energy very differently. Panels may work; it has not been shown.
Does my horse have to be clipped for red light therapy?
The evidence favours clipping. In a study of 20 Thoroughbreds, clipped areas showed greater increases in vein diameter and a smaller rise in surface temperature, which the authors interpreted as more photobiostimulation and less wasted heat. Separate work in dogs found that shaving significantly increased photon transmission.
Does my horse's colour affect red light therapy?
Yes, and more than coat length does. Photon transmission drops significantly as coat pigment increases, and in large animals black hair has been found to block near-infrared light almost entirely for measurement purposes. Dark horses are the hardest case; grey and light coats are the most favourable.
Is a laser better than an LED panel for horses?
For evidence, yes — every positive equine trial used a laser. For physics, the difference is less about the light being coherent and more about how much energy reaches tissue and over what area. The honest position is that laser has the evidence and panels have the theory.
Can I use my human red light panel on my horse?
Physically yes, and the wavelengths are the same ones studied. But the dose reaching tissue through a coat is unknown, and the only equine LED trial showed no wound-healing benefit. Treat it as unproven, clip the area, and speak to your veterinarian first — particularly for lameness, which needs diagnosis before any therapy.
Sources
- Michanek P., Toth T., Bergström E., Treffenberg-Pettersson H., Bergh A. Effect of infrared and red monochromatic light on equine wound healing. Equine Veterinary Journal, 2021;53(1):143–148. PMID 32285517
- Hochman-Elam L.N., Heidel R.E., Shmalberg J.W. Effects of laser power, wavelength, coat length, and coat color on tissue penetration using photobiomodulation in healthy dogs. Canadian Journal of Veterinary Research, 2020;84(2):131–137. PMID 32255908
- Zielińska P., Soroko-Dubrovina M., Śniegucka K., Dudek K., Čebulj-Kadunc N. Effects of High-Intensity Laser Therapy on Skin Surface Temperature and Vein Diameter in Healthy Racehorses with Clipped and Non-Clipped Coat. Animals, 2023;13(2):216. PMID 36670756
- Pringle J., Roberts C., Kohl M., Lekeux P. Near infrared spectroscopy in large animals: optical pathlength and influence of hair covering and epidermal pigmentation. The Veterinary Journal, 1999;158(1):48–52. PMID 10409416
- Miranda M.B., Barros A.C.S., da Rocha R.B., Magalhães A.T., Cardoso V.S. Qualitative Comparison of LED and LASER Effects on Cutaneous Wound Healing: A Systematic Review of Experimental Studies. Cell Biochemistry and Function, 2026;44(1):e70161. PMID 41540806
- Millis D.L., Bergh A. A Systematic Literature Review of Complementary and Alternative Veterinary Medicine: Laser Therapy. Animals, 2023;13(4):667. PMC9951699
- Haussler K.K., Manchon P.T., Donnell J.R., Frisbie D.D. Effects of Low-Level Laser Therapy and Chiropractic Care on Back Pain in Quarter Horses. Journal of Equine Veterinary Science, 2020;86:102891. PMID 32067657
- Huang Y.-Y., Chen A.CH., Carroll J.D., Hamblin M.R. Biphasic Dose Response in Low Level Light Therapy. Dose Response, 2009;7(4):358–83. PMID 20011653
