Class 4 MLS Laser Therapy vs. Red Light Therapy: What’s the Difference?
If you’ve been searching for non-invasive ways to relieve chronic pain, speed up injury recovery, or reduce inflammation from post operative swelling you’ve likely come across both Red Light Therapy and Class 4 MLS Laser Therapy.
While both use light energy to stimulate cellular healing—a process known as photobiomodulation—they are far from identical. Understanding the difference between a home-use red light panel and medical-grade Class 4 MLS laser therapy can help you choose the right treatment for your health goals.
Light Source: Coherent Laser vs. Scattered LED
The most fundamental difference comes down to the source of light:
Red Light Therapy (LEDs): Uses light-emitting diodes (LEDs) that project incoherent, scattered light. Because the light waves spread out in multiple directions, much of the energy reflects off the skin surface or scatters in the top layers of tissue.
Class 4 MLS Laser Therapy: Uses a high-performance coherent laser beam. Coherent light travels in concentrated, parallel waves, allowing the photon energy to penetrate dense tissue without losing power at the skin surface.
Depth of Tissue Penetration
How deep the light energy travels determines what conditions each therapy can treat:
Surface-Level Target (Red Light): Standard red light therapy operates primarily in the 630 nm to 850 nm spectrum using low power. It penetrates roughly 1 to 5 millimeters into the skin, making it great for superficial conditions like skin health, minor wound healing, and surface-level circulation.
Deep-Tissue Target (Class 4 MLS Laser): MLS (Multiwave Locked System) therapy uses dual, synchronized wavelengths (808 nm continuous and 905 nm pulsed) powered by a Class 4 laser engine. This enables the light to reach 1.2 to 2 inches (3–5 cm) into muscles, tendons, ligaments, spinal discs, joint capsules, and nerve pathways.
Key Takeaway: If your pain originates in deeper structures—such as a herniated disc, knee joint, rotator cuff, sciatic nerve, post surgical swelling from knee, shoulder replacement or spinal surgery—red light panels cannot deliver enough photon density to reach the problem site. Class 4 MLS lasers are specifically designed to treat these deep-seated conditions. This assists the Lymphatic drainage system to drastically reduce pain and swelling increasing your healing time by 30%.
Key Comparisons
Red Light Therapy uses low-power, non-coherent LED light measured in milliwatts, penetrating 1 to 5 mm into the skin. Primarily used for skin renewal and surface-level relief, treatments typically take 15 to 30 minutes per area and are widely accessible in home panels, spas, and gyms.
Class 4 MLS Laser Therapy delivers high-power, coherent laser light at up to 25+ watts, penetrating 1 to 1.2 inches deep into tissue and joints. Designed for deep inflammation, severe pain, and joint or nerve repair, it achieves results in 8 to 15 minutes per session and is administered in professional chiropractic or medical clinics.
Why "MLS" Technology Makes a Difference
Standard Class 4 lasers can generate heat if left on one spot. Multiwave Locked System (MLS) technology solves this by combining two synchronized light wavelengths simultaneously:
Continuous Wave (808 nm): Targets inflammation and swelling by promoting fluid drainage and cellular repair.
Pulsed Wave (905 nm): Targets pain signals directly, providing rapid analgesic (pain-relieving) effects.
By locking these two waves together, MLS Laser Therapy delivers rapid therapeutic doses deep into tissue without risk of thermal damage or discomfort. Treatments are completely painless, non-invasive, and take less than 15 minutes.
Which Therapy Do You Need?
Choose Red Light Therapy if: You are looking for cosmetic skin benefits, superficial muscle relaxation, or mild post-workout recovery across large skin surface areas.
Choose Class 4 MLS Laser Therapy if: You are dealing with acute injuries, chronic joint pain, post surgical swelling from knee replacement, shoulder replacement. MLS laser is also affective for spinal surgery, spinal disc issues, sciatica, plantar fasciitis, neuropathy, or deep tendonitis that has not responded to surface treatments.
Experience MLS Laser Therapy at Casto Chiropractic
At Casto Chiropractic, we utilize Class 4 MLS Laser Therapy to help our patients heal faster by 30%. We offer specific treatment plans to assist with patients recovering from chronic or acute pain, as well as, post surgical swelling, spinal surgery. MLS laser therapy can reduce reliance on pain medication, and avoid unnecessary surgery.
If chronic pain or an injury is keeping you from living life to the fullest, contact our office today to schedule a consultation and see if MLS Laser Therapy is right for you.
Call today for your free consultation.
Check out our YouTube channel for testimonials! YouTube
-Nichole Casto, D.C. & Jason Casto, D.C.