A new laser hit the market in 2009 for body contouring. It’s called Zerona. We don't offer this service (we use the UltraShape), and here's why.

Zerona uses five low-energy laser heads emitting 635nm (red) light with each laser generating 17milliwatts output. By way of comparison a typical laser pointer emits 5milliwatts of the same red light. So the Zerona is nothing more than a fancy-looking device with energy output equivalent to 17 laser pointers.

Zerona Canada has a very impressive looking website full of before and after photos, testimonials, and videos from the likes of Dr. Oz. After carefully reviewing the website, I was seriously thinking about buying a machine. It's that convincing.

But after further research, I have serious doubts. If I didn’t, I’d buy a Zerona tomorrow and start offering treatments. [When I first wrote this in March, 2012 there were four Zerona lasers available on the used market. Six months later I found 10 listings. This in itself makes me wonder. If it works so well, why are there so many for sale?]

A scientific study1 done  prior to the invention of Zerona showed that fat cells exposed to low level laser energy release their fatty contents through temporary pores. [Note: this was not a study of the Zerona. It was simply a study on the effects of red light on fat cells. Using this scientific evidence, Erchonia set out to develop the Zerona.]

One of the foundations of scientific method is that studies have to be reproducible. In other words, the study has to be done again by someone else, and similar results have to be found in order for scientists to conclude that the results are accurate. It is noteworthy that the findings of this study could not be reproduced in a second study by another group of researchers two years later2. So the effect of red light on fat cells is questionable.

But for the sake of argument, let's assume that the Zerona really does trigger the release of fat from cells. What happens next?

The Zerona Canada website states that the “fat is passed through the body during its normal course of detoxification”. This statement is aimed at people with no science background. It is meaningless and erroneous. What does “passed through” mean? As a physician, I have no idea what this means. And the term “detoxification” has no place in a discussion of fat metabolism. Fats are not toxins. They are energy storage molecules [and have other important functions in the endocrine and nervous systems].

Here’s what happens next. The fat that is released is taken up by the lymphatic system and eventually finds its way back into the bloodstream via the thoracic duct in the chest.  Once the fat is in the blood the body will do one of two things with it. These are the same two things it does when fat is absorbed from the intestines after a fatty meal. It will either burn it for energy or it will put it back into storage i.e. it will put it back into fat cells. It doesn’t leave the body in urine or feces; it gets burned or stored.

The primary energy molecule of the human body is glucose. If glucose is available, that’s what the body prefers to use. If glucose is not available, fat is the next choice as a source of energy. If both fat and glucose are available, the glucose gets burned, and the fat is put into storage. So you need to be in a low glucose state to burn the fat that has been released during a Zerona session. That means you need to be eating a low carbohydrate diet and burning more energy than the available glucose can provide. That means diet and exercise!

So we’ve established that the fat will go back into storage unless you are dieting and exercising. The next question is: Where will that fat be stored? The answer is: in any fat cell that has room for it. And that includes the Zerona-emptied fat cells. They are still alive, they have available storage capacity, and they are fat cells. They’re designed to store fat. It’s what they do! They’re not going to stay empty forever. Once the trigger for fat release is gone [Zerona treatments], the cells will revert to their normal function. They will fill up again.

There is only one published study of the Zerona3. To the scientific community, there are several concerns about the design of this study that draw its conclusions into question.It was conducted by Erchonia [the manufacturers of the Zerona] in order to get FDA clearance to sell the device i.e. It was not independent4. It was not a blinded study. It used a small number of patients. It only measured results at two weeks [very short-term]. Statistical analysis of the data followed some questionable practices.

Notable facts from that study are:
1) 63% of the test subjects met the criteria the researchers established for deeming the treatments to be a success. 37% did not meet the criteria.
2) 70% of the test subjects were satisfied with the results [as measured at two weeks]. You can do the math.

The Zerona uses red light equivalent to a collection of laser pointers to supposedly trigger release of fat from cells. But the effect of red light on fat cells is questionable. One study says it works. Another study says it doesn't.

Even if it does work initially, the fat cells will simply fill up again. There are no long-term studies to show long-lasting benefits.

I'll need to see long-term studies from independent researchers4 before I can recommend this treatment to my patients. I simply don’t believe that there is a lasting benefit from cold laser therapy for body contouring beyond the benefits of diet and exercise.

Buyer beware!

Dr. Philip Kritzinger MD

March, 2012

Updated October, 2012

1) Neira R, Arroyave, Ramirez H, et al. Fat liquefication: Effect

of low-level laser energy on adipose tissue. Plast Reconstr. Surg. 2002;110:912–922.

2) Brown, Rohrich, Kenkel, and Young, et. al. (Brown SA, Rohrich RJ, Kenkel J, Young L, Hoopman J, and Coimbra M. Effect of Low-Level Laser Therapy on Abdominal Adipocytes before Lipoplasty Procedures. Plast. Reconstr. Surg. 2004; 113:1796-1804.)

3) Robert F. Jackson, MD,Doug D. Dedo, MD, Greg C. Roche, MD, David I. Turok , and Ryan J. Maloney. Low-Level Laser Therapy as a Non-Invasive Approach forBody Contouring: A Randomized, Controlled Study. Lasers in Surgery and Medicine 2009; 41:799–809

4) The only study released so far on the Zerona was co-authored by Ryan Maloney, the medical director of Erchonia, the manufacturers of the Zerona laser.