If laser therapy didn't work for you before, the problem probably wasn't laser therapy — it was the laser.
Two Technologies That Share a Name and Almost Nothing Else
"Laser therapy" appears on clinic websites across the country. What those clinics don't tell you is that the machines behind that phrase vary by a factor of more than a hundred in power output — and power is what determines whether light reaches the tissue that's actually causing your pain.
Cold lasers, also called low-level laser therapy (LLLT), typically operate between 0.1 and 0.5 watts. Class IV lasers, also called high-intensity laser therapy (HILT), operate at 10 to 60 watts. That gap is not a minor technical distinction. It determines whether the light penetrates your skin or reaches the muscle, nerve, joint, or disc underneath it.
At Joint & Spine Laser Center, we use a Summus Class IV laser running at 60 watts — the same equipment tier used by NFL and Olympic athletic training staffs. Most clinics in this region use cold lasers in the half-watt range, if they use a laser at all.
The Three Numbers That Tell You Everything
The comparison between Class IV and cold laser comes down to three measurable specifications: power output, penetration depth, and session count.
Power Output
Cold laser: 0.1–0.5 watts
Class IV laser: 10–60 watts
Our Summus unit runs at 60 watts. That is not a marketing claim — it is a published device specification. Ask any clinic you're considering to state their laser's wattage in writing. If they won't, that is useful information.
Penetration Depth
A cold laser at 0.5 watts penetrates approximately half an inch below the skin surface. That is sufficient for surface-level tissue — minor skin wounds, superficial inflammation. It is not sufficient to reach a herniated disc, a sciatic nerve, a knee joint, or a shoulder that has been painful for months.
A 60-watt Class IV laser penetrates three to four inches into tissue, reaching deep muscle, bone surface, joint capsule, and nerve structures. That is where most chronic pain originates.
Session Count
Because a Class IV laser delivers a full therapeutic dose in five to ten minutes per session, patients typically complete a course of treatment in fewer visits than low-level laser protocols require. Cold laser protocols often call for twenty or more sessions to accumulate a comparable energy dose — if the device is capable of reaching the target tissue at all.
We Used to Offer Cold Laser. We Stopped.
This clinic has been in practice for more than 20 years. For part of that time, we offered cold laser therapy. We discontinued it because the results were not sufficient for the patients we treat — people with deep-tissue injuries, nerve pain, disc problems, and joint degeneration.
That is not a position we arrived at from a brochure. It came from watching patients not improve and asking why. The answer was consistent: the device wasn't reaching the problem. When we transitioned to Class IV, outcomes changed. That history is why we explain this comparison as plainly as we do.
Why Your Previous Laser Treatment May Not Have Worked
If you've already paid for a course of laser therapy somewhere and saw little or no improvement, the most likely explanation is that the device used was not powerful enough to reach the tissue responsible for your pain.
This is not a failure of laser therapy as a concept. It is a mismatch between tool and target. A 0.5-watt laser is not the wrong tool for every condition — it is the wrong tool for deep-tissue pain, and deep-tissue pain is what most patients coming through our door are dealing with.
Before assuming laser therapy doesn't work for you, it's worth knowing what class of laser was used and at how many watts.
Two Questions to Ask Any Clinic Before You Book
Most clinics do not publish their laser wattage. Many list "laser therapy" as a service without specifying the device class. Before scheduling anywhere, ask:
- What class is your laser?
- How many watts does it run at?
A clinic with a legitimate Class IV device will answer both questions without hesitation. If the answer is vague, or if the clinic says "we use a cold laser" and presents that as equivalent to Class IV, you have the information you need.
We publish our equipment specifications and our pricing. You can call us at (715) 623-2123 and ask anything you want before committing to a consultation.
Frequently Asked Questions
What is the difference between cold laser and Class 4 laser therapy?
Cold laser (LLLT) operates at 0.1–0.5 watts and penetrates roughly half an inch below the skin. Class IV laser therapy operates at 10–60 watts and reaches three to four inches into tissue, including deep muscle, nerve structures, joints, and disc material. The core difference is power output and the depth that power makes possible.Why didn't cold laser therapy work for me?
For most patients with chronic or deep-tissue pain, cold laser doesn't produce results because the light never reaches the source of the problem. Half an inch of penetration is not enough to address a compressed nerve, a degenerated disc, or a damaged joint. If your pain is deep, the device needs to be powerful enough to get there.How deep does a Class 4 laser penetrate?
A 60-watt Class IV laser penetrates approximately three to four inches into tissue. That is sufficient to reach the sciatic nerve, lumbar discs, knee joint, shoulder rotator cuff, and other deep structures that are commonly the source of persistent pain.Is Class IV laser therapy worth it compared to cold laser?
For surface-level tissue — minor wounds, skin inflammation — cold laser may be adequate. For anything deeper, the wattage difference is clinically significant. Class IV laser delivers more energy per session, reaches deeper structures, and typically requires fewer visits to complete a treatment course.How many watts is the laser at Joint & Spine Laser Center?
We use a Summus Class IV laser at 60 watts. That is the same equipment tier used by NFL and Olympic athletic training programs. We are happy to discuss the device specifications before you schedule anything. What should I ask a clinic before booking laser therapy? Ask two things: what class is the laser, and how many watts does it operate at. A Class IV device at 10 watts or higher is meaningfully different from a cold laser at 0.5 watts. If a clinic won't give you a direct answer, treat that as your answer.
Ready to Find Out If Class IV Laser Is Right for You?
We offer a complimentary consultation and will review any existing imaging you've had done. If we can help you, we'll tell you how. If we can't, we'll tell you that too.
