You may have heard of red light therapy but aren’t quite sure what it actually involves. In recent years, red light therapy has gained increasing attention in health, recovery, and skincare. At the same time, the concept can feel unfamiliar if you don’t know what’s actually happening inside the body.
In simple terms, red light therapy uses specific wavelengths of red and near-infrared light to influence biological processes in the body. The light penetrates into the tissue, where it can support cellular energy production - without surgery, medication, or other invasive procedures. That’s why it’s often described as a non-invasive way to support the body’s natural repair processes.
But how does it actually work at the cellular level? And what is red light therapy used for in practice?
What is red light therapy?Red light therapy, also known as photobiomodulation, uses specific wavelengths of light to influence cellular activity. It primarily uses:
These wavelengths are used because they can penetrate the skin and reach tissues beneath the surface. It’s also important to understand what red light therapy is not:
Red light therapy is a non-invasive approach designed to support the body’s natural processes, rather than replace them. |  |
 | How does red light therapy work?To understand how red light therapy works, we need to look at what happens at the cellular level. Inside almost every cell in the body are tiny structures called mitochondria. Often described as the powerhouses of our cells, mitochondria produce energy in the form of ATP (adenosine triphosphate). ATP is essential for many processes in the body, including:
When the body is under strain, injured, or experiencing stress, energy production can become less efficient. This is where red light therapy comes in. Red and near-infrared light are absorbed by the mitochondria, which may stimulate biochemical processes that increase the availability of ATP. A simplified way to look at it is: Light → affects the mitochondria → increases ATP production → supports the body’s natural functions When cells have better access to energy, this may help support faster repair of muscles, tendons, and skin, reduce perceived pain and inflammation, and improve blood circulation and oxygen delivery to tissues. This doesn’t mean that light alone “heals” the body. Rather, it may help create better conditions for cells to do what they’re already designed to do. |
What does red light therapy do, and how does it affect the body?Red light therapy uses red and near-infrared light to support the body’s natural processes at the cellular level, which may provide a range of health benefits. Key benefits of red light therapy include: Support for muscle and joint painMay help reduce perceived pain and support better muscle and joint function. Learn more about its effects on pain and muscle discomfort here. Reduced stiffness and improved mobilityOften used to support mobility in areas affected by stiffness or physical strain. Faster recovery after exerciseStudies suggest that red light therapy may help reduce muscle soreness and support recovery after physical activity. Support for strain-related discomfortUsed in sports and rehabilitation as a complement for overuse and localized tissue-related concerns. Overall well-being and circulationMany people use red light therapy as part of a broader health and wellness routine. Learn more about optimizing your health with red light therapy here. In sports and rehabilitation settings, red light therapy is often used alongside physiotherapy and exercise programs. It’s important to note that results can vary from person to person. Red light therapy isn’t a one-size-fits-all solution, but it can be a useful tool as part of a holistic approach to health. |  |
 | What is the difference between red and near-infrared light?Both are used in red light therapy, but they have different properties. Red light (600–650 nm) has a shorter wavelength and works closer to the surface. It is often used for the skin and tissues near the skin’s surface. Near-infrared light (750–850 nm) has a longer wavelength and can penetrate deeper into the body, making it particularly relevant for muscles, tendons, and joints. It’s important to understand that not everything described as “red light” reaches deeper tissues. Effective red light therapy for muscles and joints requires the right wavelengths and sufficient penetration. By combining red and near-infrared light, it’s possible to target both superficial and deeper tissues at the same time - an important factor for effective treatment and recovery. |
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When should you use red light therapy?Red light therapy can be particularly useful if you experience muscle or joint pain, stiffness, poor circulation, or want to support faster recovery after exercise. It may also help with general physical discomfort and support skin health. For convenient use at home, you can place a wearable device directly on the area that needs the most attention, such as your calves, thighs, knees, or shoulders. Just a few minutes of red light therapy at home each day may help improve circulation, reduce inflammation, relieve pain, and support energy levels. At-home infrared light therapy makes it easy to build this into your daily routine as a simple yet effective habit. |  |
 | The history of red light therapyAlthough red light therapy has gained increasing attention in recent years, the technology is far from new. Research into how light affects biological processes has been ongoing for more than 100 years. This comprehensive review on PubMed explores how the field has evolved from its earliest discoveries to today’s medical applications. As early as 1903, Danish physician Niels Ryberg Finsen received the Nobel Prize in Physiology or Medicine for his work with light therapy. Later, in 1967, Hungarian researcher Endre Mester discovered that red laser light could stimulate biological processes related to tissue repair and hair growth. This is widely considered the beginning of what we now know as photobiomodulation. Throughout the 1970s, ’80s, and ’90s, research into red and near-infrared light continued to grow, particularly in areas such as wound healing, pain, inflammation, and muscle recovery. In the 2000s, NASA also helped generate greater interest in the technology through research into how light could support health and recovery during space missions. Today, red light therapy is used both in clinical settings and at home, and the technology has been studied in thousands of published papers across areas such as pain management, recovery, skin health, and overall well-being. Red light therapy has evolved from a niche area of light research into one of the more established forms of light-based health and recovery technology. |