Beware of misleading physics when buying a Class IV Laser. A 10 watt or even a 20 watt laser that a company claims it has might not be accurate. We had to test these lasers in order to find out what we weren't being told. I interviewed some of the people that used to work with Class IV companies that started their own companies and I learned things that conflicted what the spec sheets and sales people have told me.

10 Watts of power will give a certain penetration so why the F@#% does a 7.5 watt laser penetrate further than a 10 watt class IV laser. Or how can a 15 watt laser penetrate almost double what a 12 watt laser can. If a patient goes in and wants a therapeutic dose and the laser doesn't deliver it, THAT IS A SCAM!.

With the Class IV lasers that I have found, there are two types. Continuous, those that work on a continual basis and pulsed ones,,that usually have a 50% duty cycle, meaning that they only work 50% of the time. But that is not the main issue. What makes the difference even more when it comes to specs that you can take word for word and literally go off the spec sheet, is that some Class IV lasers have single wavelengths and the other type has dual wavelengths. Based on my tests which you can do simply with a bit piece of meat, is that each type has a different absorption and reflection curve depending on the power output. I also noticed that having two dual lasers that are the same power is not cumulative and doesn't penetrate more than a single wavelength. 

With dual wavelength, only the laser that is the strongest does the job. So when I used a 10, 12 or the 15 watt laser, the penetration is cut by half. A 15 watt continuous wavelength that gives 15 watts on only one wavelength instead of being divided over two lasers is going to penetrate with half the power or go twice as much. This is how I found that a 7.5 watt continuous laser is more powerful than a 10 watt laser. This only matters if you need to penetrate really deep. If just for the hands, you don't need anything over 500 milliwatts and none of this matters. With recent technology in class IV lasers, lasers are now trending towards continuous single wavelengths. Although the are more expensive, you can get twice the power or you can buy a laser that is lower wattage and continuous that can equal out to a laser that has twice the power but is pulsed. It gets very confusing and most people just look to see which laser is the most powerful without learning this stuff and end up over paying.

Although frequencies can be added, a laser that worked yesterday will not be obsolete or outdated. Nothing new except for non-inhibiting lasers has just come out. The institutes and research studies are funded by the companies. Companies will never publish a study not in their favor and without objectivity. There are honest, earnest sellers and there are sheer liars. The class 3 sellers have their opinions based on their studies and are going to extremes to show you that a class 4 laser is not the best. A class 3 and class 4 sellers can both be right but you need to know what studies and examples they are basing their theories on. Will a class 4 laser burn you as the class 3 sellers claim? Well, you can hold any light with heat "still" for a minute or put your hand over the stove and it won't burn you but hold it still and you will see what this theory is based on. NO! If used properly, a class 4 laser cannot burn you. Does it yield better results from its high power? That depends on what the demands are for.

Class 4 lasers do penetrate the deepest into the tissues but this depends on the TYPE of tissue being treated. I do not go by the pictures on some class 4 laser websites because it can be misleading and outright manipulating the truth. Even doctors that have studied the body can get scammed and this is sad because clients trust them and depend on the doctors to know their lasers. How deep their class 4 lasers penetrate not only depends on the type of tissue but the treatment techniques and how the technician uses the laser at different power settings.

Higher powered class 4 lasers offer many advantages over class 3 lasers as well as lower power class 4 lasers. The strongest lasers have more room to burn people but take the shortest time while the lesser powered ones take longer and a doctor can't see as many patients per hour with it. In a high volume clinic, where there are several doctors using that laser and trying to schedule as many appointments as possible, they will have to decide on how strong of a class 4 laser they need based on how many patients they expect to use it daily and how much time they can use it on each patient. More power has proven to get better results with stubborn conditions like neuropathy, spinal stenosis and disc herniations. 

Choosing a Pulsed Class 4 VS a Continuous Class 4 Laser
The pulsed laser is much different than the continuous lasers. The continuous class 4 lasers are designed for serious failures, not just "oh, my lower back hurts from sitting at my computer every day or waking up on the wrong side of the bed". It seems that only the elite pain clinics have these and they charge way more for their sessions which make these unaffordable for most people. If doctors can't afford the price point of the continuous lasers and are buying lower powered lasers and telling their clients to come back for more sessions than they would need if they had this type of laser, it is unfair to the patient. The patients that need fewer sessions usually call me with their success from the continuous class 4 lasers. The continuous laser is far more expensive than the pulsed, usually 17K and up. Most doctors just starting out cannot afford these and most of the people calling me for cold lasers are trying to catch up with the senior chiropractors and other doctors who have success with these lasers and are trying to get in on the niche. I am sorry but it is not cool when a doctor uses some weak laser and charges the client the same as those with the continuous class 4s. Sure, if a doctor pays 35 to 50 grand for a top end laser, they can charge the market price.

The continuous lasers are great when the situations are serious. Just having tightness in your hands shouldn't demand this type of lasers. The continuous lasers aren't as advertised as the pulsed probably because there is a lot more training involved with these, not that I am saying you don't need training with the pulsed class 4s. The high traffic clinics who have untrained high turn around technicians typically won't have the continuous lasers. Again, most clinics with doctors just starting out won't have lasers that cost 35k or more or at least very rarely.

If you are a client that is seeking class 4 laser therapy, honestly, I would only get the treatment done if it is done by a doctor who has BEEN TRAINED to use that laser or technicians where have been qualified. Class 4 lasers are a different breed than the class 3. They work quicker but come with their own pros and cons. The class 3 lasers are not better or worse than class 4 nor is pulsed than continuous. They all work. It is just what is the application you are using it for and your needs of your clinic and the demands for the laser in your clinic. I have found that those with the class 4 pulsed have something to say about the continuous and the doctors that have the class 4 continuous always have similar things to say about the pulsed ones.
Difference between Continuous Wave (CW) and Pulsed laser
Most lasers are so called "Continuous Wave", abbreviated CW. CW lasers are on or off, just like a flashlight.
Some higher-end cold laser devices allow the user to select modes where the lasers diodes flash on and off. This is not to be confused with super pulsed lasers, where the pulsing is the required method of controlling the laser diode. (This type of pulsing is usually at hundreds of thousands or millions of times per second.) The pulsing discussed here is low frequency, from less than one hertz (one flash per second) to tens of kilohertz (thousands of times per second). Often the pulsing is slow enough for you to see it.
Some clinical studies have found that the therapeutic effect of pulsed laser is significantly greater than CW treatment. However, having the correct frequency is just as significant. On study I read found a significant improvement when using infrared pulsed at 10Hz (compared to CW). However, the same study found that the effect at 100Hz was no different to CW.
Do you need pulsing? Many users of pulsed LLLT devices will attest to the value of having the pulsing function, especially when used for diagnostics. Since the body responds differently according to the frequency, this characteristic can be exploited to quickly hone in on a particular ailment. It is fare to say that a pulsing feature adds to the usefulness of an LLLT device, but bear in mind that using this feature effectively will require more advanced training.

Square wave, sine wave and complex waveforms.
Most pulsing LLLT devices modulate the laser diodes so that they are either on or off. As a function of time, this is represented as a square wave, with rapid transitions between the off and on state. Some devices modulate the laser diodes so that their energy output follows a sine wave form. Square wave and sine wave output devices offer a range of programming capabilities, including the ability to produce pulses of a single frequency, multiple frequencies, or scanning through a range of frequencies. Some devices even offer the ability to output multiple frequencies at the same time from a single diode. This is sometimes referred to colloquially as a "scalar wave" (a non-scientific term). There is insufficient research to meaningfully compare the efficacy of these different technologies. 

My prerequisites for selling Class IV Lasers
Must be FDA cleared
Must work at "true" class IV Settings 
Must be "stimulatory" to deep pathologies 
Must have new divergent beam technology if continuous powered to avoid burns
Must state "burn" cases and documentation upon request
Must be currently in at least 100 chiropractic clinics
Must be currently in at least 75 veterinarian clinics
Company must already be around 5 years or longer
Must be made in an ISO-13485 approved manufacturing plant

Not all Class IV lasers are the same. A 500 Milli-Watt laser can be reduced to 300 watts after transferring through the optics. Better optics give better output power. (See my write up on peak output power versus phony output power, real constant output.) 
Note: With non-inhibiting lasers, it does not matter about the power. If "ANY" light touches the body or substance, even if the light is very weak from a nearly dead battery, it does not matter. The light is only a carrier wave. Just one photon is enough to transport frequencies carried by the laser. This is why you can shine the laser through clothes and it still works. 

Negative Photo Destructive Light Reactions:
Very similar lasers used in laser surgery that can destroy cells and cut and burn, be cautious with some of the lasers in this class. You do not want to shine a laser to inhibit pain to the point that the cells being shined cannot survive the thresh hold that is not in the parameters of that laser. The cells in the body can be destroyed by too intense of light and even burned to the point that even time cannot help and the destruction is irreversible. Please study the difference between inhibiting lasers and non-inhibiting lasers. They both can work great but work in 180 degree opposite ways.

Killing the cells... if putting toot much energy is apostasis. (Killing of the, the opposite of photo stimulation.. instead of stimulating.. its killing the energy producing part of cell does off.. not good.

If you need help choosing a Class IV laser from the major brands out there, take my laser quiz.
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Update: I will not sell lasers that are not FDA cleared. Too many doctors have gotten sued since I started this site. I will let everyone know which lasers are now approved
I will never trash talk lasers that did not get approved or those that were never cleared with the FDA. See my requirements for lasers that are not FDA cleared.
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