Can Red Light Therapy Reduce Body Fat? (Geek Edition)
OK you guys, let’s get right to the point. Can red light therapy really reduce body fat? Answer: While it’s not Wegovy-level fat loss, it’s also not nothing. In this geek version of the answer, learn exactly what the science says about using red light therapy for fat loss.
Deliver 3.6 joules per sq. cm. of 635 nm red light releases fat from cells. Studies using 660 nm and 880 nm also work. Vibration or exercise after treatment flushes fat from the intercellular space so that it cannot reabsorb. Science says yes, red light therapy can melt fat.
Red light therapy changes the rules of spot reduction.
Spas and plastic surgeons use the technology for spot fat removal. Now it’s available for home use, without a prescription.
If you’re here to see the red light therapy device that stars in the fat loss space, go to my guide to the Nushape Lipo Wrap now.
How Red Light Therapy Reduces Belly Fat
Every fitness instructor says you can’t spot reduce, but clinicians know better. Red light flushes fat by poking microscopic holes in fat cells. Whether belly fat, thigh fat, or hip fat, the light does spot reduction on areas treated.
There are two “gotchas,” and they’re not small.
First, you need to get the right amount of light energy. Too little or too much light energy will leave the fat right where it started.
Second, you need to move after treatment. This can be on a vibration machine, or you can do actual exercise.
It’s not that you need to “burn” the fat. It’s that the fat has poured from the cell to the space between the cells. Movement edges it into the lymph system and then out of the body. Without movement, the fat reabsorbs into the fat cells.
Red Light Specifications for Belly Fat Loss
We usually think of an electrical device’s energy as how much electricity it takes to make it run. A 1,600-watt hair dryer is more powerful than a 1,000-watt hair dryer.
With red light therapy, we are less concerned with energy into the device, and more concerned about the photon energy (light energy) coming out of the device. We measure that in milliwatts (thousandths of a watt).
Look for Irradiance – the Photon Energy Delivered
The energy measurement we care about in a red light therapy device is its irradiance, which is how much photonic (light) energy it delivers to the target per second.
You need only 10 1/1000ths of a watt to deliver belly fat-releasing light to the body. As opposed to laser energy, a red light therapy device is low-energy. If the power is too high, the body does not have the healthy reaction we want.
A Simple Red Wavelength Can Reduce Belly Fat
635 nm (nanometers) describes the wavelength of the light that reduces the fat. Light travels in waves. The distance from the peak of one wave to the peak of the next is the wavelength. There is 635 billionths of a meter distance between wave peaks in the light waves that reduce fat.
635 nm is not the only effective wavelength. 680 nm and 880 nm release fat as well. In all likelihood, a large range of wavelengths reduce fat. You don’t need to worry too much about the exact wavelength because the entire range around 635 nm, 680 nm, and 880 nm are almost certainly bioactive.

LEDs output a range of wavelengths. A 635 nm light is not really just one wavelength of 635 nm. 635 nm is just the wavelength with the peak amount of energy. You’re getting a range around that 635 nm of perhaps 615 nm to 655 nm, give or take a few billionths of a meter.
It is probably the case, then, that all the wavelengths in the 600 and 800 ranges release fat, as we have seen bioactivity in other areas from a wide swatch of wavelengths in these areas. 808 nm is highly absorbent in water and is effective in brain therapy, for instance. There’s every reason to believe that a light that is bioactive in one area is bioactive in all others.
We are only being careful about naming wavelengths to follow the science of tested wavelengths.
Light Measurement at the Target
To standardize the measurement from device to device, we measure the light that reaches the target in square centimeters. The amount of light that reaches a square centimeter per second is a joule (“jewel”). You need a dose of 3.6 J/cm^2 (3.6 joules per squared centimeter) to get the fat cell to release its contents.
The Empty Grapes Study
In a study published in Plastic Reconstruction Surgery, researchers tested red light on fat removed during lipectomies (fat removal surgeries).
They took the fat samples from twelve women during their respective surgeries. Using a 10 mW (low power) laser outputting 635 nm red light, they tested the light’s effects on the fat.
They used four testing parameters of 0, 2, 4, and 6 minutes of treatment. The zero-minute sample was the control.
The 2, 4, and 6-minute treatments corresponded to 1.2 J/cm^2, 2.4 J/cm^2, and 3.6 J/cm^2 photon deliveries, respectively.
They examined the fat under scanning electron microscopes. Within four minutes of treatment, the cells released 80% of their contents. The treatment created microscopic holes in the cell walls. Fat poured through the holes into the space between the cells.
- 2 J/cm^2 released the least amount of fat (80%)
- 6 J/cm^2 released the most amount of fat (99%)
The most effective treatment was 10 mW for 6 minutes delivering 3.6 J/cm^2 of 635 nm light.
The researchers noted that the treated cells looked like deflated grapes. The cell membranes shriveled like emptied balloons.

Neira R, Arroyave J, Ramirez H, Ortiz CL, Solarte E, Sequeda F, Gutierrez MI. Fat liquefaction: effect of low-level laser energy on adipose tissue. Plast Reconstr Surg. 2002 Sep 1;110(3):912-22; discussion 923-5. doi: 10.1097/00006534-200209010-00030. PMID: 12172159.
Does Red Light Therapy for Fat Loss Require Diet or Exercise?
Fat loss does not require diet or exercise, but maintaining the results is another matter.

Fat Flushing Study I
Red light reduced belly fat in a “fat flushing” study published in Obesity Surgery. The red light therapy removed 8/10ths of an inch off subjects’ waistlines. Clinicians treated the subjects two times per week for 30 minutes per session.
Both 635 nm and 680 nm were effective in reducing belly fat. No diet or exercise was required for fat loss. But after treatment, the lost inches started to come back. After treatment, the subjects did not move, and some of their fat cell contents were reabsorbed. In the follow-up, 8% of the fat had returned.
Caruso-Davis MK, Guillot TS, Podichetty VK, Mashtalir N, Dhurandhar NV, Dubuisson O, Yu Y, Greenway FL. Efficacy of low-level laser therapy for body contouring and spot fat reduction. Obes Surg. 2011 Jun;21(6):722-9. doi: 10.1007/s11695-010-0126-y. PMID: 20393809; PMCID: PMC5225499.

Fat Flushing Study II
Red light therapy removed 3.51 inches across the waist, hips, and thighs, according to a study published in Lasers in Surgery and Medicine.
Clinicians treated subjects with 635 nm red light three times per week for two weeks. Subjects lost an average of almost an inch of belly fat, more than an inch from the hips, and over half an inch from each thigh.
This study also supports the theory that you can flush fat out of cells without diet or exercise. Without a followup, however, we don’t know if subjects kept the fat off. Then again, if results were similar to those in the study above, an 8% re-gain is not that shabby.
Jackson RF, Dedo DD, Roche GC, Turok DI, Maloney RJ. Low-level laser therapy as a non-invasive approach for body contouring: a randomized, controlled study. Lasers Surg Med. 2009 Dec;41(10):799-809. doi: 10.1002/lsm.20855. PMID: 20014253.
Cells Reabsorb Fat without Exercise/Movement After Treatment
Light lets fat out of the cells. The catch is, you do see it re-absorbing in some studies. It’s not a question of burning the fat with exercise, but of moving it out of the intercellular space for disposal.
Clinicians offering red light fat reduction offer vibration machines just for this purpose. The Planet Fitness red light booth includes vibration, for example. The Contour Light Body Sculpting procedure includes 10 minutes of whole-body vibration after the procedure.
How Long Do Red Light Therapy Fat Flush Results Last?
Contour Light is an FDA-cleared red light therapy for waist, thigh, and hip reduction. It’s pretty much the model for your home therapy. This is what they advise their clinicians to tell their clients.
- do 10 sessions in 3 weeks
- do periodic tune-ups
- drink water after treatment
- use the vibration place or exercise after treatment; a walk is sufficient, but interval exercise is best
- avoid heavy meals before and after treatment
- limit caffeine and alcohol
Why is My Red Light Therapy Fat Flush Failing?
If you don’t see results within three sessions, do some troubleshooting to find out why.
You need at least 3.6 joules per sq. cm. of photon energy to release the maximum amount of fat. 2.3 joules worked in one study, but at a lesser rate. You might not be getting enough light per treatment. Add ten minutes to your treatment times.
You might not be flushing the released fat. Avoid heavy meals, caffeine, and alcohol. Exercise after treatment to flush the fat out of the intercellular space. Red light can reduce belly fat, and it’s up to you to flush it out of your system.