Laser vs LED Red Light Therapy: What's the Difference, and Which Is Better?

Having supplied Photizo red light therapy devices for over 11 years, one question I'm frequently asked is whether LED red light therapy can be as effective as the laser treatments offered by veterinary surgeons and veterinary physiotherapists.

Over the years, I've spoken to many horse and dog owners whose animals have received professional laser therapy. Some have subsequently purchased a Photizo so they can continue regular treatments at home rather than paying for repeated veterinary laser appointments.

I've received positive feedback from customers who have made this transition and have been happy with the results.

Interestingly, I've also found that veterinary surgeons and veterinary physiotherapists who use professional laser therapy themselves recommend Photizo to their clients as a way of continuing photobiomodulation treatment at home.

Although professional lasers and Photizo use different light technologies, both work through photobiomodulation. The Photizo gives owners the opportunity to provide regular treatments at home, potentially reducing the need for repeated and often expensive professional laser appointments.

So, what is the difference between laser and LED red light therapy? Does laser light penetrate deeper? Is a more powerful device necessarily more effective?

Both technologies use photobiomodulation, but there are important differences in how they deliver light.

Let's look at the science behind both technologies and what this means for horse and dog owners.

What is the Difference Between Laser and LED Red Light Therapy?

Laser therapy and LED red light therapy are both forms of photobiomodulation (PBM), a treatment that uses specific wavelengths of light to stimulate biological processes within the body's cells.

Although the two technologies produce light differently, they share the same fundamental principle: delivering light energy to tissues to encourage cellular activity and support the body's natural healing processes.

So what makes them different?

Laser Therapy

Lasers produce a highly concentrated, directional beam of light. The light waves are coherent, meaning they travel in a synchronised pattern.

Therapeutic lasers are widely used by veterinary surgeons and veterinary physiotherapists to treat musculoskeletal conditions, including injuries affecting muscles, tendons and joints.

Depending on their classification and power output, professional lasers require specialist training and appropriate safety precautions.

LED Red Light Therapy

LED stands for Light Emitting Diode.

Unlike lasers, LEDs produce non-coherent light, meaning the light waves are not synchronised in the same way. LED light also tends to spread out more than a laser beam.

However, this doesn't mean LED light cannot penetrate tissue or stimulate biological activity.

Both laser and LED devices can deliver therapeutic wavelengths of red and near-infrared light.

Does the difference actually matter?

This is where the science becomes particularly interesting.

Early photobiomodulation research concentrated almost entirely on lasers. Consequently, laser therapy became established as the preferred technology for many healthcare professionals.

However, subsequent research has demonstrated that LEDs can also produce photobiomodulation effects.

Scientists now recognise that the effectiveness of treatment depends on several factors, including:

• Wavelength: The type of light used and how it interacts with tissue.
• Power density: The rate at which light energy is delivered to a particular area.
• Treatment dose: The amount of light energy delivered, often measured per square centimetre.
• Treatment frequency: How often treatment is administered.

Although lasers and LEDs have different optical properties, the fact that a device uses laser technology does not automatically make it more effective than an LED device.

Ultimately, what matters is whether sufficient light energy reaches the intended tissue to produce the desired biological response.

Is Laser Therapy More Powerful Than LED Red Light Therapy?

When it comes to photobiomodulation, delivering sufficient light energy to the intended tissue is essential.

Not all red light therapy devices deliver the same amount of light energy. There can be considerable differences in power density between professional therapeutic lasers, handheld LED devices and wearable LED wraps. If you'd like to understand why not all LED devices are equal, I've explained the differences in more detail in my article Photizo vs LED Wraps blog

This is particularly important when treating deeper tissues, where only a proportion of the light delivered at the skin's surface reaches the intended treatment area.

While increasing power does not automatically guarantee better therapeutic results, a device must deliver sufficient energy to produce the desired biological response.

Understanding Power Density

Power density, also known as irradiance, measures the rate at which light energy is delivered to a particular area. It is usually expressed in milliwatts per square centimetre (mW/cm²).

This is an important consideration when comparing different red light therapy devices.

For example, the Photizo Vetcare is a handheld LED photobiomodulation device with the following specifications:

• Power output: 1,300 mW
• Average power density: 194 mW/cm²
• Peak power density: 340 mW/cm²
• Wavelengths: 633 nm red light and 850 nm near-infrared light
• Treatment cycle: 31 seconds

These specifications demonstrate that LED devices can deliver substantial levels of light energy without using laser technology.

Why the Correct Light Dose Matters

Photobiomodulation has what scientists call a biphasic dose response, meaning that the biological response to light can vary depending on the amount of energy delivered.

Too little light energy may produce little or no therapeutic response, while increasing the dose can improve the response. However, there is an optimal range, which can vary according to the condition being treated and the intended therapeutic effect.

For example, when using Photizo Pain Relief on humans, multiple treatment cycles may be used on the same area to achieve the required pain relief.

When treating animals, a more cautious approach is appropriate because they cannot communicate their response to treatment in the same way.

This demonstrates why both power density and treatment dose are important considerations when choosing and using a photobiomodulation device.

What Does This Mean for Horses and Dogs?

Professional laser therapy can be a valuable treatment option, particularly when administered by veterinary surgeons and veterinary physiotherapists.

However, LED photobiomodulation also has an important role, especially when regular treatment is required.

The ability to administer treatment consistently at home can be a practical advantage for owners managing animals with ongoing musculoskeletal conditions.

Although the two technologies deliver light differently, both can stimulate photobiomodulation.

The important consideration is whether the device delivers an appropriate treatment dose for the intended application, rather than whether the light is produced by a laser or an LED.

How Does Photizo Compare with a Professional Veterinary Laser?

Professional veterinary lasers can deliver considerably higher power outputs than LED devices such as Photizo. However, comparing the wattage of two devices doesn't necessarily tell us which will produce the best therapeutic results.

Professional veterinary lasers typically offer adjustable power settings, allowing practitioners to vary the energy delivered according to the condition being treated. 

This is also why understanding the correct treatment dose and using equipment appropriately is so important.

In the UK, higher-powered Class 3B and Class 4 lasers are subject to safety restrictions because incorrect use can cause serious eye injuries and, in some circumstances, skin burns. These lasers are not considered suitable for general consumer use and require appropriate safety precautions when used professionally.

Photizo Vetcare, by comparison, delivers red and near-infrared light simultaneously through a pre-programmed 31-second treatment cycle.

While higher-powered lasers can deliver larger amounts of energy more quickly, this doesn't automatically mean they will produce better therapeutic outcomes.

For horse and dog owners, one of Photizo's biggest advantages is the ability to administer regular treatments at home.

I've also received positive feedback from customers who have purchased a Photizo rather than continuing to pay for repeated professional laser appointments.

Does Laser Light Penetrate Deeper Than LED Light?

One of the most common claims about laser therapy is that it penetrates deeper into the body than LED red light therapy.

But is this necessarily true?

The ability of light to penetrate tissue depends on more than whether it comes from a laser or an LED.

Several factors influence how deeply light can travel, including:

• Wavelength: Different wavelengths penetrate tissues differently. Near-infrared light generally penetrates deeper than visible red light.
• Power density: The intensity of light reaching the skin influences how much energy is available to reach deeper tissues.
• Tissue composition: Skin, fat, muscle and other tissues absorb and scatter light differently.

Why Near-Infrared Light Matters

Both lasers and LEDs can produce near-infrared light.

Visible red light, typically around 630–660 nm, is particularly useful for treating more superficial tissues.

Near-infrared wavelengths, commonly around 800–850 nm, generally penetrate further into tissue, making them relevant when treating structures beneath the skin.

The Photizo Vetcare combines red light at approximately 633 nm with near-infrared light at 850 nm.

This allows the device to deliver both wavelengths during its pre-programmed 31-second treatment cycle.

Does the Laser's Concentrated Beam Give It an Advantage?

Lasers produce coherent, directional light, whereas LEDs emit non-coherent light that spreads more widely.

However, once light enters biological tissue, it is scattered and absorbed. This scattering reduces the importance of the laser's original coherence.

Research has demonstrated that LEDs can produce photobiomodulation effects without requiring coherent laser light.

What matters is how much light energy reaches the intended tissue and whether that dose is sufficient to produce a biological response.

Some high-powered lasers can deliver more energy to deeper tissues than lower-powered LEDs, but this is not simply because they use laser technology.

Can Near-Infrared Light Penetrate Clothing?

Research has demonstrated that near-infrared LED light can pass through certain fabrics.

A study published in Scientific Reports in 2025 investigated the transmission of near-infrared light at 850 nm through clothing.

The researchers found that the fabrics tested were nearly 100 times more transparent to 850 nm near-infrared light than to visible light, demonstrating that clothing does not necessarily prevent near-infrared light from passing through.

This is particularly interesting because Photizo Vetcare also uses near-infrared light at 850 nm.

However, the amount of light transmitted depends on the type of fabric, its thickness and other characteristics. The study demonstrates light transmission through clothing but does not establish that Photizo delivers an equivalent therapeutic dose through fabric.

For consistent treatment, applying Photizo directly to the skin remains preferable wherever practical.

So, Does Laser Therapy Penetrate Deeper?

Not necessarily.

Both lasers and LEDs can deliver wavelengths capable of penetrating biological tissue. However, the amount of light energy reaching deeper structures depends on the wavelength, power density, treatment technique and characteristics of the tissues being treated.

A high-powered professional laser may deliver considerably more energy to deeper tissues than an LED device, but this doesn't automatically guarantee better therapeutic results.

Ultimately, it's the amount of light energy reaching the intended tissue, rather than simply whether the device uses laser or LED technology, that matters.

Scientific References

Heiskanen & Hamblin (2018) – Photobiomodulation: Lasers vs Light Emitting Diodes? link

This scientific review examines the differences between laser and LED light sources and their application in photobiomodulation.

2026 Review – Light-Emitting Diodes: Advances, Challenges and Applications in Musculoskeletal Pain link

This review examines the use of LEDs in photobiomodulation for musculoskeletal pain, including the importance of treatment parameters and the available evidence.

Jeffery et al. (2025) – Longer wavelengths in sunlight pass through the human body and have a systemic impact which improves vision link

UK Health Security Agency's laser safety Guide

Susannah Secrett - October 2026