Class IV Laser Therapy

Class IV laser therapy — also called high-intensity laser therapy or photobiomodulation — uses concentrated therapeutic light to stimulate cellular processes involved in healing and pain modulation.

It's worth clearing up the name immediately, because it causes a lot of confusion: this is not a surgical laser. Surgical lasers are designed to cut or ablate tissue. Therapeutic lasers deliver energy at wavelengths and intensities chosen to produce biological effects without damaging tissue.

What "Class IV" actually means

This is the single most misunderstood point in laser marketing, so we'll be direct about it.

The class number is a safety classification based on the risk of eye injury — not a measure of therapeutic power or effectiveness. Class IV simply means the device outputs more than 500 milliwatts, which is why protective eyewear is mandatory during treatment. Class 3B devices operate at 500 milliwatts and below.

How it works

Therapeutic laser light penetrates the skin and is absorbed by components inside your cells — principally cytochrome c oxidase, an enzyme in the mitochondria. That absorption triggers a cascade of downstream effects:

• Increased cellular ATP production — more available energy for tissue repair
• Modulation of inflammatory mediators
• Increased local blood flow and microcirculation
• Stimulation of fibroblast activity, supporting collagen and tissue remodelling
• Altered pain signalling along peripheral nerve pathways

What we use it for

Laser therapy is most useful for tendon, joint and soft tissue conditions, particularly stubborn ones that haven't fully settled with manual therapy alone:

• Plantar fasciitis and heel pain
• Achilles and other tendinopathies
• Tennis elbow and golfer's elbow
• Rotator cuff conditions and shoulder pain
• Osteoarthritis pain, particularly knee and hand
• Chronic neck and back pain
• Myofascial pain and persistent trigger points
• Post-surgical tissue healing and wound healing
• Sports injuries, both acute and chronic

Where the evidence is strong — and where it isn't

We think you're better served by an accurate picture than an enthusiastic one.

Photobiomodulation has a reasonable and growing evidence base for chronic tendinopathies, osteoarthritis pain, and superficial soft tissue conditions. The FDA first cleared a Class IV therapeutic laser in 2003 for musculoskeletal pain, inflammation and tissue healing.

The evidence is weaker and less consistent for acute, deep-tissue injuries, where many studies show no clear functional advantage over conventional treatment. A real limitation across the research is wide variability in the parameters used — wavelength, power, dose, and treatment frequency differ so much between studies that comparing them is genuinely difficult.

The practical takeaway: laser is a useful adjunct with a strong safety profile, not a standalone cure. Anyone presenting it as a miracle treatment is overselling it.

What a session is like

The handpiece is moved slowly and continuously over the treatment area. Most people feel a pleasant, spreading warmth — there's no pain, no needle, and no downtime afterwards. Everyone in the room wears protective eyewear, which is a requirement at this power level, not an optional precaution.

The laser portion typically runs five to fifteen minutes depending on the size of the area, and is usually delivered within a longer appointment alongside other treatment.

How many sessions

The effect is cumulative rather than immediate, so a course is normal. Acute problems often respond within three to six sessions; longer-standing conditions typically need eight to twelve. If you've had several sessions with no change at all, that's a signal to reassess the diagnosis — not to keep buying sessions.

Safety and when we avoid it

Class IV laser has a strong safety profile in trained hands. We avoid or modify treatment in these situations:

• Directly over known active cancer
• Over the abdomen during pregnancy — other regions are generally fine
• Direct eye exposure — protective eyewear is worn by everyone present
• Over areas of active bleeding
• Where you take photosensitizing medication — tell us what you're on

Laser vs. shockwave — which one?

Both are useful, and they overlap. In broad terms, shockwave therapy applies mechanical energy and tends to suit chronic, degenerative tendon problems and calcific conditions, and it's often uncomfortable during treatment. Laser applies light energy, is painless, and suits inflammatory and pain-dominant presentations plus more superficial tissue.

Which we recommend depends on your diagnosis, how long you've had it, and your tolerance — often we use both across a treatment plan. TECAR therapy is a third option we'll sometimes reach for.

How it fits into a treatment plan

Laser is rarely the whole answer. It works best as an adjunct that reduces pain and supports tissue healing while the underlying problem is addressed through joint treatment, soft tissue therapy, and corrective exercise. If a clinic is offering laser alone as a complete solution for a mechanical problem, be skeptical.

Coverage

Laser therapy is not covered by OHIP. Delivered as part of a chiropractic appointment, the visit may be claimable under your extended health plan's chiropractic coverage — see our guide to what covers chiropractic in Ontario.

Class IV laser at THE WAY Chiro

We offer Class IV laser therapy at our Oakville clinic at 2380 Bristol Circle, just off the QEW at Winston Churchill — convenient for patients from Oakville, Mississauga and Burlington. Evening appointments three days a week and Saturday hours are available.

For a deeper dive into specific conditions, see our article on what Class IV laser therapy treats.

Frequently asked questions