Red light therapy for weight loss has been increasing in popularity. However, there is currently no expert consensus on whether it actually works.

Red light therapy, which people also call low-level laser therapy (LLLT), has been the subject of a number of scientific studies.

While the available research generally shows that LLLT provides some fat loss benefits, the study designs are inconsistent. Additionally, a lack of data makes it difficult to say whether the results are long term or clinically relevant.

Read on to find out whether it is worth trying red light therapy for weight loss.

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Due to inconclusive research, there is some controversy surrounding the question of whether red light therapy can help with weight loss.

Studies include a pilot study from 2020 involving 60 adults with overweight. The results showed a modest 0.8-inch (2 cm) reduction in waist circumference following twice-weekly LLLT treatments over 6 weeks. However, there was no control group to compare the results with.

Another study, from 2017, specifically targeted abdominal girth using a combination of three wavelengths of low-level laser, including red, infrared, and blue. The study involved 18 females who each underwent a total of 12 LLLT sessions during the course of the study.

The results showed significant reductions in upper, middle, and lower abdomen size, with all of the study participants experiencing positive results.

In 2018, researchers looked into the potential benefits of LLLT with exercise training to reduce body fat. The study involved 49 females with obesity aged 20–40 years, divided into intervention and sham groups.

The participants underwent three sessions per week of exercise training with phototherapy after exercise for 4 months.

All participants experienced improvements. However, only those who received LLLT showed reduced interleukin-6, which is a marker of immune health, and increased WNT5 signaling, which is needed for the development of healthy cells.

This group also experienced bigger changes than the sham group in relation to:

Another study from 2017 also found that receiving LLLT in addition to treadmill walking resulted in a greater reduction in abdominal fat and body weight.

However, one study actually found an increase in fat tissue thickness in 8 out of 17 participants.

Researchers still need to work out the definitive mechanism of action behind LLLT. However, it might relate to the absorption of laser light into the adipocytes, which leads to increased cyclic adenosine monophosphate production, a type of cell signal or messenger.

This then stimulates an enzyme called cytoplasmic lipase, which converts triglycerides to fatty acids and glycerol. These substances can pass through pores, causing the adipocytes to shrink.

Additionally, one animal study from 2018 found that infrared photobiomodulation therapy, which is another name for LLLT, improved glucose metabolism and insulin regulation in the fat tissue of mice with obesity caused by a high fat diet.

Photobiomodulation has also been shown to increase muscle mass gained after training.

The 2017 study mentioned above reported no side effects relating to the LLLT in any of the following three treatment frequencies:

  • three times per week for 4 weeks
  • twice per week for 6 weeks
  • once per week for 12 weeks

However, another study from 2017 observed side effects of LLLT in two participants. Both people developed broken skin, one at their appendectomy scar and the other on their lower back.

The researchers concluded that devices applied directly to the skin are less safe than devices with treatment panels separated from the skin.

Some studies suggest that there are benefits to red light therapy for weight loss. Some have involved LLLT and other weight loss methods, such as exercise training or treadmill walking.

Each person should decide whether to proceed with red light therapy to lose weight by talking with their doctor and weighing the benefits and drawbacks for them individually.

As the CDC explains, healthy weight management is about lifestyle rather than a specific diet or program. It is about establishing healthy eating patterns in combination with regular physical activity and stress management.

A review in Nutrients from 2020 reported that healthier alternatives to the Western diet tend to feature more plant-based foods, such as:

  • fresh fruits and vegetables
  • whole grains
  • legumes
  • seeds and nuts

These diets include the Mediterranean diet, the Dietary Approaches to Stop Hypertension (DASH) diet, and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet. They also tend to be lower in animal-based foods, especially fatty and processed meats.

Additionally, the American Association of Clinical Endocrinologists and the American College of Endocrinology recommend moderate-intensity aerobic exercise for at least 150 minutes per week for the medical care of people with obesity. They note better outcomes with increasing intensity and amounts of exercise.

There is also evidence that actively managing stress can help a person manage their weight. For instance, in one study from 2018, 45 adult participants received standard instructions for a healthy lifestyle.

Of these, 22 people in the intervention group also attended an 8-week stress management program. This involved breathing from the diaphragm, doing progressive muscle relaxation, doing guided visualization, and receiving instructions about healthy dietary habits.

The intervention group achieved a significantly greater reduction in BMI compared with the control group, with losses of 3.1 kilograms per square meter (kg/m2) in the intervention group compared with 1.74 kg/m2 in the control group.

A number of studies have found that red light therapy may help with weight loss. However, the study designs have been inconsistent and have not looked at long-term effects. So it is difficult to draw firm conclusions.

Some of the studies suggest that red light therapy could be a useful addition to following an exercise program or walking on a treadmill to lose weight. The procedure appears to be relatively safe if the device does not directly attach to the skin.

However, a person may also want to incorporate other evidence-backed weight loss strategies, including following a healthy dietary pattern, exercising, and managing stress.