Red Light Therapy - Does it Help or Cause Cancer? (Home Use)

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In a Nutshell

Before we discuss the various studies that have been conducted with red light therapy and cancer, here's a brief summary:

  • Potential anti-cancer effects: In some contexts, light therapies like PDT have been used to target and treat certain types of cancer cells.
  • Increase in tumor size in mice: One study [2] raised concerns that in certain conditions, 642nm wavelength might promote tumor growth (where cancer cells pre-exist).
  • A contradictory study says that red light therapy is safe even when malignant lesions are present [5].
  • Can red light therapy cause cancer? Current research does not indicate that red light therapy causes cancer.
  • Is red light therapy safe for cancer patients? There are studies that show cancer reduction and one that shows tumor size growth. There's not enough evidence yet to say RLT is safe for cancer patients and more research is needed.
  • Can red light therapy cause cancer cells to grow? Some studies suggest so (more research is needed)
  • Can infrared light cause cancer? We did not find any research to substantiate that infrared rays can cause cancer.
  • Is there a risk of cancer by using red light therapy? Current research suggests not.
  • Given the studies on mice where cancer cells grew, if you are someone recovering from cancer or recently recovered, there is no evidence that light therapy is safe (or unsafe), so please consult your physician before using red light therapy. Note: Studies in mice do not always directly translate to human outcomes.
  • If you don't have cancer, currently, no direct link between red light therapy and cancer development has been established, which makes red light therapy safe to use. 
  • More research is needed to fully understand the various effects of red light therapy on cancer cells and we highly recommend consulting your health practitioner to obtain advise that's right for your circumstances. 

In recent years, red or infrared light therapy (RLT) has been getting a lot of attention from the medical community. What has everyone so excited is the ability of this treatment process to have such a positive impact on the treatment of various physical and psychological issues. Among the issues that RLT seems to offer great home benefits are hair replacement, vision correction, skin ailments, and even psychological issues like depression and anxiety.

While it offers great hope that RLT might end up being a super cure of sorts for lots of issues, there is also great hope infrared light therapy can have a material impact on the fight against cancer. For centuries, cancer has been an enemy versus the mortality of the human race. There are treatments available such as surgery, radiation, and chemotherapy, but they are such invasive treatments. The medical community has been looking for a better option that causes less damage. They may have found it with RLT.


The Science Behind Red Light Therapy

To help you understand how RLT could be useful in the battle against cancer, some scientific knowledge about the red light therapy process could be useful.

Each human cell is filled with organelles called mitochondria. Mitochondria is an energy source for cell growth and regeneration. When cells get damaged or die, they cause a lot of physical or even psychological issues for the individual as the mitochondria lie dormant. However, the energy from infrared light has proven to be the perfect energy boost for mitochondria.

This is how the magic works. When the infrared light hits the mitochondria, the light brings the mitochondria to life. That immediately results in damaged cells getting repairs and new cells being generated. Cell reparation and growth are the keys to the health benefits that seem to follow.

Based on this knowledge, you can probably begin to anticipate how the RLT process would work with cancer. Of course, there are three issues at hand. First, could RLT play a role in killing off cancer cells? Second, to what degree could RLT help replace dead cancer cells with healthy growing cells? Finally, would RLT not cause cancer cells to grow?

Let us investigate.

Can red light therapy help treat cancer?

To answer this question, we have to relate back to the two questions brought up in the above section. First, does RLT have a way to contribute to the killing of cancer cells? According to researchers, including Dr. Hisataka Kobayashi at the NIH’s National Cancer Institute (NCI) [1], the answer to this question appears to be yes.


According to their work, researchers found that by employing monoclonal antibody (mAb) therapy in mice, they could release antibodies that would attach to cancer cells. They discovered that when these antibodies are hit with infrared light, the cancer cells started dying immediately. This process has been successful through much testing on test subjects (animals) with tumors of various types and sizes.

Note: The appropriate red or light therapy wave frequency for treating most cancers would appear to be in the low-800s nm and mid-600s nm ranges. At these wave frequencies, the light should be able to penetrate the skin and the soft tissue of the organs. The irradiance of the device should be at least 100mw/cm squared for the light to be able to penetrate deep enough to be effective.

Science backed red light therapy devices for home

If RLT can assist in the killing of cancer cells, there is already evidence that the process will wake up cellular mitochondria, prompting the growth of new cells and the reparation of damaged cells in the same areas. As the RLT ignites the immune system to new levels, there is a lot of healing that should take place.

Now, the concern shifts to whether RLT will cause cancer cells to grow and repair.

Can you get cancer from red light therapy?

At this point, there is no evidence a person can get cancer from RLT. A great research piece [4] summarising light therapy and cancer research, states that patients receiving red light therapy had statistically better progression free survival than those in the placebo group.

However, there is evidence from one study [2] that shows RLT could cause existing tumors and cancer cells to grow. From what has already been described as the science behind RLT, we know the process works to incite cell growth. Remember, cancer cells are simply human cells that have mutated into cancer cells. They do have mitochondria as an energy source for growth.

At issue would seem to be wave frequency. At higher levels, say 850 nm or higher, there is a good chance tumors will grow. This makes RLT for cancer a bit of a balancing act. Before this process can be used on humans, there needs to be more information related to the risk/reward and possible side effects of this process.

Is red light therapy safe for cancer patients?

There is no clear answer to this issue at this time. As we stated above, there is a possibility RLT could spur cancer cell growth. There needs to be a lot more research on this issue before anyone can give a definitive answer to this question. That research will need to be done on human subjects. Some of the appropriate clinical trials are underway [3].

Red light therapy for various types of cancer

As RLT gains respect as a possible treatment for cancer, the medical community will want to start focusing on what types of cancer will apply to this process. As of now, there is evidence that indicates all types of cancer may be subject to RLTs effectiveness or growth. Let us take a quick look at four of the most common forms of cancer and the likelihood RLT is a possible solution.

Breast cancer

As a soft tissue cancer close to the surface, the RLT process is showing positive results with breast cancer.

Brain cancer

There are issues related to the treatment of brain cancer with RLT. It would seem to have something to do with skull penetration levels. At safe wave frequencies at around 600nm to 700 nm, the ability of infrared light to penetrate the skull is limited. The solution would be using higher wave frequencies, which would result in a little more risk. However, the risk could be worth it given the serious nature of brain cancer.

Skin cancer

Since infrared light penetration is always a key consideration, skin cancer is likely the easiest form of cancer to treat with RLT. In fact, the treatment of skin cancer with RLT is proving to have a very high degree of success.

Lung cancer

Much like breast cancer, the RLT process is showing positive results with lung cancer as another soft tissue endeavor.

Red light therapy vs photodynamic therapy for cancer

This particular comparison has to be made with a certain degree of conjecture. Based on testing information, red light therapy appears to help kill cancer cells without causing further damage to skin and organs. With photodynamic therapy, there is possible residual damage from the treatment process.

Also, there is a possibility using RLT therapy could result in the promotion of cancer cell growth. That is not a possibility with photodynamic therapy.

Does red light therapy cause skin cancer?

Again, there is no evidence that red light therapy causes cancer. However, there could be an issue with this process promoting and growth and spreading of existing tumors or cancer cells.

Does red light therapy prevent skin cancer?

To reiterate, there is strong evidence that red light therapy in conjunction with the right antibodies could help prevent skin cancer. Without the addition of the right antibodies, RLT might have the opposite effect and actually ignite cancer cell growth.

Red Light Therapy Devices

Until the FDA authorizes the use of infrared light therapy to treat cancer, the subject of devices is sitting on the backburner. It is not clear if people will be able to manage the RLT process at home or have to depend on clinics.

Our devices

If the time comes when RLT for cancer is approved and authorized at home, patients will be happy to learn there is a growing population of quality devices that people might be able to use for cancer treatment in a home environment. It still remains to be seen.


[1] - Targeted Light Therapy Destroys Cancer Cells (opens in a new tab)

[2] Study: Increase in tumor size in mice (opens in a new tab)

[3] - Photoimmunotherapy (opens in a new tab)

[4] (opens in a new tab)

[5] Study - Red Light Therapy safe when malignant lesions are present (opens in a new tab)

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I had an atypical meningioma removed in November of 2021 and went through 28 treatments of radiation in 2022. So far I have stable MRI’s but they can’t guarantee that there aren’t some stray atypical cells left behind. Is red light therapy safe to use to regrow hair or would it penetrate my skull and potentially make the atypical cells grow? I tried clicking on the 2. link but it wants to me consent to giving them all my information and I am not comfortable with that.

Tara, thank you for sharing your experience. Regarding using red light therapy for hair regrowth after an atypical meningioma and radiation treatment, it's important to be cautious. Some studies, including one involving mice, have suggested that red light therapy might stimulate cancer cell growth. Therefore, it's best to consult with your oncologist or a medical professional who knows your case well before proceeding with red light therapy. Always prioritize safety and informed medical advice in your health decisions.
RLT Home Admin November 01, 2023

I “probably” have follicular mycosis fungoides. A skin biopsy suggests it but (many*) more biopsies and other tests are needed for a definite diagnosis. However, aged 85 in two months, I don’t feel inclined to undergo what one specialist clinic refers to as “years of tests*” before starting treatment when such are my symptoms that – along with that pathologist’s initial report – it’s hard to see what else it can be but FMF. And so, I’ve started UVB self-treatment with a stand-up light box. It works quite well on the patch rashes I’d had on my back – but not on other skin problems, particularly scalp rashes. (FMF is characterised by “mimicking many skin conditions”). I am therefore backing up my UVB with Red Light self-treatment (despite some uncertainty about the advisability of it). I should add that the treatment known as PUVA is standard for FMF and has quite a high success rate But it takes no fewer than about 70 treatments which, at my age, requiring as it would – thrice weekly 200Km round trips for six months – would probably kill me sooner that FMF! If I were younger, I would probably take a conventional route. As it is, watch this space if you’re interested in this DIY “experiment.”

Tony Whieldon
Dear Tony,

Thank you for sharing your experience and approach to managing your skin condition, which you suspect to be follicular mycosis fungoides. It's understandable why you'd opt for self-treatment methods given the challenges and demands of more conventional treatments at your age.

UVB therapy is a recognized treatment for certain skin conditions and glad it's working well for you. As for adding Red Light therapy, while it's known for its skin healing properties, its efficacy in treating conditions like FMF is not well-established. Given the unique nature of FMF, which can mimic many skin conditions, it's challenging to predict how effective these treatments will be for your scalp rashes.

Your willingness to share your journey with this DIY "experiment" is valuable, and many might find insights from your experiences. Wishing you the best in your treatment journey and hoping for positive outcomes.
RLT Home Admin September 21, 2023

any thoughts on RLT for cataracts?


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