MLS laser therapy is a type of light-based treatment that uses two synchronized laser wavelengths to reduce pain, inflammation, and swelling in muscles and joints. It falls under the broader category of photobiomodulation, which means using specific wavelengths of light to trigger healing responses in cells. The FDA cleared MLS laser devices in 2005 for temporary relief of muscle and joint pain, arthritis pain, muscle spasms, and stiffness, as well as for increasing local blood circulation.
How the Two Wavelengths Work Together
What distinguishes MLS from other therapeutic lasers is the “Multiwave Locked System” design. The device fires two wavelengths simultaneously: a continuous 808-nanometer beam and a pulsed 905-nanometer beam. These are synchronized and locked together, which is intended to distribute energy more evenly across the treatment area than a single-wavelength laser can.
The 808 nm wavelength penetrates tissue and primarily targets pain and inflammation. The 905 nm pulsed wavelength delivers higher peak power in short bursts, reaching deeper tissues without generating excessive heat. By combining these two beams in a controlled, synchronized pattern, the device aims to address both surface-level and deeper sources of pain in a single session.
What Happens Inside Your Cells
The light energy from the laser is absorbed by an enzyme in your mitochondria, the energy-producing structures inside every cell. Under normal conditions, a molecule called nitric oxide binds to this enzyme and slows it down, reducing the cell’s ability to produce energy. When photons from the laser hit the enzyme, they knock the nitric oxide loose. Because nitric oxide blocks oxygen at a ratio of about 1 to 10, even a relatively small amount of light energy can free up a large amount of cellular respiration. The result is increased oxygen consumption and more ATP, the molecule your cells use as fuel for repair and recovery.
The freed nitric oxide also plays a role on its own. Once released into surrounding tissue, it acts as a vasodilator, widening blood vessels and improving local circulation. This helps bring fresh oxygen and nutrients to the injured area while carrying away waste products that contribute to swelling.
Effects on Inflammation and Swelling
One of the most consistently documented effects of photobiomodulation is a broad reduction in inflammation. This is particularly relevant for joint disorders, traumatic injuries, and soft tissue damage. The laser light has been shown to shift the behavior of immune cells called macrophages, reducing their inflammatory activity and lowering the production of inflammatory signaling molecules like certain interleukins and prostaglandins.
The effect is surprisingly selective. In normal, healthy cells, the laser can actually activate certain immune pathways. But in cells that are already in an inflammatory state, it dials those same pathways down. This means the therapy tends to calm overactive inflammation without suppressing the immune response in healthy tissue. Research in animal models has also demonstrated reductions in edema, with measurable decreases in tissue swelling and inflammatory enzymes.
Conditions Commonly Treated
The FDA’s clearance specifically covers temporary relief of muscle and joint pain, stiffness, arthritis pain, muscle spasms, and increasing local blood circulation. In clinical practice, providers use MLS laser therapy for a range of musculoskeletal complaints:
- Plantar fasciitis and other foot and ankle pain
- Tendinitis in the shoulder, elbow, or Achilles tendon
- Osteoarthritis and rheumatoid arthritis flare-ups
- Low back pain, both acute and chronic
- Sports injuries including sprains, strains, and muscle tears
- Post-surgical recovery to manage pain and speed tissue repair
- Neuropathy and nerve-related pain
A clinical study on chronic low back pain used a protocol of 12 MLS laser sessions delivered twice per week, targeting multiple points along the lower spine. The treatment is applied to a broader range of conditions in practice, though the strength of evidence varies depending on the specific condition.
What a Treatment Session Looks Like
MLS laser therapy is noninvasive and painless. You sit or lie in a comfortable position while the provider holds the laser device over the affected area. Most people feel nothing during the treatment, though some report a mild warmth. There are no needles, no incisions, and no anesthesia. Sessions typically last between 10 and 15 minutes depending on the size of the treatment area and the condition being addressed.
For chronic conditions, the standard protocol is roughly 12 sessions, usually scheduled twice per week over six weeks. Acute injuries sometimes require fewer treatments. Most people begin to notice improvement within three sessions, though optimal results typically require 7 to 10 treatments. The effects are cumulative, meaning each session builds on the previous one, so consistency with the treatment schedule matters.
There is no downtime after a session. You can return to your normal activities immediately, which is one reason the therapy appeals to athletes and people who want to avoid the recovery period associated with more invasive procedures.
Safety and Who Should Avoid It
MLS laser therapy has a strong safety profile for most people. Side effects are rare and generally limited to mild, temporary warmth at the treatment site. However, there are several groups who should not receive laser therapy.
The well-established contraindications include a history of malignant cancer (particularly over or near the tumor site), direct exposure over the thyroid in people with hyperthyroidism, epilepsy, direct exposure to the eyes, and treatment over the abdomen during pregnancy. These are not theoretical concerns but recognized safety boundaries for all forms of therapeutic laser treatment.
Some additional situations call for caution, though the evidence is less definitive. These include active fever or infection, certain blood disorders, significant recent blood loss, and treatment near the reproductive organs. If any of these apply to you, your provider will need to weigh the risks before proceeding.
How MLS Differs From Other Laser Therapies
The therapeutic laser market includes a wide range of devices, from low-level “cold lasers” to high-power Class IV lasers. MLS occupies a specific niche. Low-level lasers use a single wavelength at low power and often require longer treatment times. High-power Class IV lasers deliver more energy but carry a greater risk of thermal damage to tissue if not carefully managed.
MLS laser therapy attempts to solve both problems by synchronizing two wavelengths at controlled power levels. The pulsed 905 nm beam allows deeper penetration without sustained heat buildup, while the continuous 808 nm beam provides consistent energy to shallower tissues. The synchronized delivery is the key technical distinction: rather than simply firing two lasers at the same spot, the system locks their emissions together in a specific pattern designed to optimize how tissue absorbs the energy.
This doesn’t automatically make MLS superior to other laser therapies for every condition. But the dual-wavelength approach does allow it to address both pain and inflammation simultaneously, which single-wavelength devices handle one at a time.
Cost and Accessibility
MLS laser therapy is widely available in chiropractic offices, physical therapy clinics, podiatry practices, and some orthopedic and sports medicine centers. A single session typically costs between $50 and $100, with a full course of 10 to 12 treatments running $500 to $1,200 depending on the provider and geographic area. Some clinics offer package pricing that reduces the per-session cost.
Insurance coverage is inconsistent. Some plans cover laser therapy under physical therapy or rehabilitation benefits, while others classify it as experimental and deny coverage. It is worth checking with your insurance provider before starting a course of treatment, as the out-of-pocket cost for a full protocol can add up quickly.