Class IV laser therapy—also known as photobiomodulation (PBM)—uses high-powered therapeutic lasers (over 500 mW) to deliver precise wavelengths of red and near-infrared light deep into tissues.
These photons stimulate the mitochondria inside cells, boosting ATP production, improving cellular metabolism, and activating biological processes that support:

• Faster tissue repair

• Reduced inflammation

• Significant pain relief

• Improved circulation and recovery

Class IV Laser Therapy

• Power Output: Over 500 mW (up to 60W+) per diode
• Designed for spot therapy and deeper targets
• Treats target areas in less time with significantly faster outcomes and often greater efficacy.

Cold/LLLT (Class III)

• Power Output: 5-500 mW per diode
• Multi diode devices designed for large treatment area or full body treatment
• Little or no sensation
• Takes several sessions typically to see benefits.

Is Class IV Laser Safe？

It’s FDA-cleared and supported by over 5,000 scientific studies.

The good news is that Class IV laser therapy has very few side effects, especially compared to surgery or medications.​

Mild Side Effects

Most people experience no side effects at all. Some might notice:

• Gentle warmth: You may feel a soothing, warm sensation during treatment. This is normal and often feels relaxing​
• Tingling: A slight tingling feeling where the laser is applied​
• Mild redness: The treated area might look slightly pink for a short time after treatment​

All of these effects are temporary and go away quickly after the session ends.​

Rare Side Effects

In rare cases, some patients report:

• Increased pain temporarily: This is uncommon but can happen, especially after steroid injections​
• Muscle soreness: Like a “bruised” feeling the next day, similar to after exercise​
• Mild dizziness: Very rare, possibly from increased blood flow causing a small drop in blood pressure​
• Minor bruising: Only if pressure is applied during treatment or if you’re on blood thinners​

It’s important to know what laser therapy doesn’t cause:

• No cancer risk: The infrared light used in therapy is non-ionizing radiation, which is completely different from dangerous X-rays. Laser therapy does not cause cancer​
• No tissue damage: Properly used, therapeutic lasers don’t burn or damage cells​
• No pain: The treatment itself is painless and comfortable​
• No downtime: You can return to normal activities immediately after treatment​
• No scarring or cuts: It’s completely non-invasiv

Note: For patients with known or suspected malignancy, direct treatment over a tumor site is generally avoided unless under specialist guidance.

Class IV laser therapy may not be appropriate for every situation.
A licensed clinician should evaluate each patient individually.

Common Precautions

Avoid or use with caution in the following situations:

• Known or suspected cancer/tumor sites
  (Light therapy is generally not applied directly over malignant areas.)

• Over the eyes without certified protective eyewear
  (Eye protection is mandatory for all persons in the room.)

• Recently injected corticosteroids in the treatment area
  (May cause temporary symptom fluctuation.)

• Photosensitive conditions or medications
  (Some drugs increase light sensitivity.)

• Pregnancy
  (Typically avoided directly over the abdomen; otherwise considered case-by-case.)

• Areas with active hemorrhage or active infection
  (Assessed individually by the clinician.)

A typical session lasts 3–10 minutes depending on the treatment area and dose.
During treatment, you will:

• Wear safety eye protection

• Feel gentle warmth

• Relax while the clinician smoothly moves the laser handpiece over the target area

Most patients report the treatment as pleasant and comfortable.

Treatment plans vary by condition:

• Acute injuries: 1–4 sessions may show improvement

• Chronic conditions: Often require a series of sessions for optimal benefit

• Post-operative or regenerative cases may follow structured protocols

The clinician will tailor the plan based on tissue response and clinical goals.

Class IV laser therapy is widely used to support the management of:

• Muscle and ligament injuries

• Tendonitis and tendinopathy

• Joint pain and arthritis

• Nerve irritation

• Back and neck pain

• Sports injuries

• Post-surgical recovery

• Soft-tissue inflammation

Clinical evidence varies by condition, and treatment is often used as part of a multimodal plan.

PBM is believed to work through several well-documented pathways:

• Enhanced mitochondrial function and ATP production

• Modulation of inflammatory cytokines

• Improved microcirculation and lymphatic flow

• Stimulation of collagen and connective tissue repair

• Reduction of oxidative stress

• Support for neuromuscular function

These physiological changes contribute to pain reduction, faster recovery, and improved tissue health.