Red Light Therapy Treats Erectile Dysfunction

light therapy for erectile dysfunction and impotence

Erectile dysfunction (ED) is a highly common problem, affecting pretty much every man at one point or another. It has a profound effect on mood, feelings of self worth and quality of life, leading to anxiety and/or depression. Although traditionally linked to older men and health issues, ED is rapidly increasing in frequency and has become a common problem even in young men. What can red light do to help men suffering from these issues?


ED Basics
Light Therapy helps ED:
Blood Flow
Ideal light for ED treatment

Erectile dysfunction basics

The causes of erectile dysfunction (ED) are numerous, with the most likely cause for an individual depending on their age. We won’t go into these in detail as they are too numerous, but it breaks down into 2 main categories:


Mental impotence

Also known as psychological impotence. This type of neurotic social performance anxiety usually stems from previous negative experiences, forming a vicious cycle of paranoid thoughts that cancel arousal. This is the main cause of dysfunction in younger men, and for various reasons is rapidly increasing in frequency.


Physical/hormonal impotence

Various physical and hormonal issues, usually as a result of general ageing, can lead to problems down there. This was traditionally the leading cause of erectile dysfunction, affecting older men or men with metabolic issues like diabetes. Drugs like viagra have been the go-to solution.

Whatever the cause, the end result involves a lack of blood flow into the penis, a lack of retention and thus an inability to start and maintain an erection. Conventional drug treatments (viagra, cialis, etc.) are the first line of defense offered by medical professionals, but are by no means a healthy long term solution, as they will upregulate nitric oxide’s effects (aka ‘NO’ – a potential metabolic inhibitor), stimulate unnatural blood vessel growth, harm unrelated organs such as eyes, and other bad things…

How can red light help with impotence? How does the efficacy and safety compare to drug based treatments?

Treating Erectile Dysfunction Safely – with Red Light?

Red and infrared light (from appropriate sources) seem to be a safe and effective treatment for a wide variety of issues, not just in humans but many animals. The following effects of red/infrared light therapy are of particular interest to erectile dysfunction:


This is the technical term for ‘more blood flow’, due to dilation (increase in diameter) of blood vessels. The opposite is vasoconstriction.

vasodilation vs constriction
Fig 1. Image showing how blood flow improves with increased vasodilation

Vasodilation is stimulated by light therapy, and also by various other physical, chemical and enivornmental factors. The mechanism for this dilation is different for all though. The reason that improved blood flow helps erectile dysfunction is obvious, and is necessary if you want to cure ED. Red light stimulates vasodilation through these mechanisms:

  • Carbon Dioxide (CO2)

    Commonly thought of as a metabolic waste product, carbon dioxide is actually a vasodilator, and the end result of respiration reactions in our cells. Red light acts to improve that reaction.

    cellular espiration with red light
    Fig 2. Illustration of oxidative metabolism (aka aerobic respiration) that occurs in mitochondria

    CO2 is one of the most potent vasodilators known to man[2], easily diffusing from our cells (where it is produced) into blood vessels, where it interacts almost instantly with smooth muscle tissue to cause vasodilation. CO2 plays a significant systemic, almost hormonal, role across the body, affecting everything from healing to brain function[2-5].

    Improving your CO2 levels by supporting glucose metabolism (which red light, amongst other things, does) is crucial to solve ED. It also plays a more local role in areas it is produced, making direct groin and perineum light therapy of interest for ED[6]. In fact, an increase in CO2 production can lead to a 400% increase in local blood flow – no wonder it helps ED.

    CO2 also helps you to produce more NO[11], another molecule related to ED, just when you need it:

  • Nitric Oxide

    Mentioned above as a metabolic inhibitor, NO actually has various effects on the body, including vasodilation[3,7]. NO is produced from arginine (an amino acid) in our diet by an enzyme called NOS. The problem with too much sustained NO (from stress/inflammation, environmental pollutants, high-arginine diets, supplements) is it can bind to respiratory enzymes in our mitochondria, preventing them from using oxygen. This poison-like effect prevents our cells from producing energy and carrying out basic functions. Red/infrared light photodissociates NO from this position, allowing mitochondria to function normally again (see Fig 4.).

    pathway for NO to cause vasodilation
    Fig 3. NO production and dilation pathway effects

    NO doesn’t only act as an inhibitor though, it plays a role in erection/arousal responses[8,9] (which is the mechanism exploited by drugs like viagra). ED is specifically linked to NO[10]. Upon arousal, NO generated in the penis leads to a chain reaction. Specifically, NO reacts with guanylyl cyclase, which then increases production of cGMP. This cGMP leads to vasodilation (and thus erection) via several mechanisms. Of course, this whole process isn’t going to happen if the NO is bound to the respiratory enzymes, and so red light essentially shifts the NO from a harmful effect into a pro-erection effect.

    Removing the NO from mitochondria, via red light, is also key to increasing mitochondrial CO2 production again. As mentioned above, Increased CO2 will help you produce more NO, when you need it. So it’s like a virtuous circle or a positive feedback loop. The NO was blocking aerobic respiration – once liberated, normal energy metabolism can proceed. The normal energy metabolism helps you use and produce NO at more appropiate times/areas – something key to curing ED.

mechanism for vasodilation from red or infrared light
Fig 4. Various mechanisms by which red/IR light causes vasodilation

Hormonal improvement


As we’ve discussed in another blog post, red light applied to the testes has been shown to raise natural testosterone levels. While testosterone is actively involved in libido (and various other aspects of health), it plays a vital, direct role in erection. Low testosterone is one of the main causes of erectile dysfunction in men. Even in men with psychological impotence, an increase in testosterone levels (even if they were already in the normal range) can break the cycle of dysfunction. While endocrine problems aren’t necessarily as simple as targetting a single hormone, light therapy seems beneficial in this area.


Not necessarily something you would link to ED, thyroid hormone status is actually a primary factor[12]. In fact, bad thyroid hormone levels are detrimental to all aspects of sexual health, in men and women[13]. Thyroid hormone stimulates metabolism in all cells of the body, in a similar way to red light, leading to improved CO2 levels (which mentioned above – is good for ED). Thyroid hormone is also the direct stimulus that the testes need to start producing testosterone. From this perspective, thyroid is a sort of master hormone, and seems to be the root cause of everything linked to physical ED. Weak thyroid = low testosterone = low CO2. Improving thyroid hormone status through diet, and even through light therapy, is one of the first things that should be attempted by men wanting to address their ED.


Another key hormone in the impotence world. High prolactin levels literally kill an erection[14]. This is best shown by how prolactin levels skyrocket in the refractory period after orgasm, significantly reducing libido and making it hard to ‘get it up’ again. That’s just a temporary issue however – the real problem is when baseline prolactin levels rise over time due to mixture of diet and lifestyle influences. Essentially your body can be in something similar to that post-orgasmic state permanently. There are several ways to tackle long term prolactin issues, including by improving thyroid status.


What’s the best type of light for this?

You’re going to want a light that outputs either red or near-infrared light – both are suitable. There are several factors to consider on top of that though:


Various wavelengths have a potent effect on our cells, but there’s more to consider. Infrared light at 830nm penetrates much deeper than light at 670nm for example. The 670nm light is thought to be more likely to dissociate NO from mitochondria though, which is of particular interest for ED. Red wavelengths also showed better safety when applied to the testes, which is important here too.

What to avoid

Heat. Applying heat to genital area is not a good idea for men. Testes are extremely sensitive to heat and one of the primary functions of the scrotum is heat regulation – maintaining a temperature lower than normal body temperature. This means any source of red/infrared light that also emits a significant amount of heat will not be effective for ED. Testosterone and other measures of fertility helpful to ED will be harmed by inadvertently heating the testes.

Blue & UV. Extended exposure of blue and UV light to the genital area will have negative effects on things like testosterone and in the long-term general ED, due to the harmful interactions of these wavelengths with mitochondria. Blue light is sometimes reported as beneficial for ED. It’s worth noting that blue light is linked to mitochondrial damage in the long term, so, like viagra, probably has negative long-term effects.

How to use it

Assuming you have a low heat source of red or infrared light, direct application for short periods throughout the day to the genital area would work to improve general function[1,6], with results being apparent very quickly for certain people. The increase in CO2 levels, leading to local vasodilation, would happen within minutes and the increases in testosterone would become apparent after a few days.

Thyroid light therapy is also a good idea for ED treatment, using a light on the front of the neck. This would improve systemic metabolism, including CO2 levels, testosterone and other downstream beneficial effects like reducing prolactin levels.

Using a source of red or infrared light anywhere on the body, even unrelated areas like the back or arm for example, for extended periods (15mins+) is something that many online have noticed beneficial effects from on ED and also morning wood. It seems that a large enough dose of light anywhere on the body, ensures molecules like CO2 produced in the local tissue enter the blood stream, leading to the beneficial effects mentioned above in other areas of the body.



  • Red & Infrared light seem very useful in treating erectile dysfunction
    • Also provide a sexual function boost to anyone
    • Various potential mechanisms including CO2, NO, testosterone.
    • Useful for either physical or psychological impotence
  • Red (600-700nm) seems slightly more appropriate but IR works too.
    • Absolutely best range may be 655-675nm
  • Applying to genitals, thyroid & body in general is helpful
    • Avoid applying significant heat to the genital area




  1. Laser light – a new, non invasive treatment for Erectile Dysfunction: a placebo-controlled, single blinded pilot study. Y. Yacobi M.D., A. Sidi M..D. –
  2. J Physiol, 2011. The cerebrovascular response to carbon dioxide in humans. A. Battisti-Charbonney
  3. Reivich M. Arterial PCO2 and cerebral hemodynamics. Am J Physiol. 1964; 206: pp. 25–35.
  4. C Iadecola. Does nitric oxide mediate the increases in cerebral blood flow elicited by hypercapnia? Proc Natl Acad Sci U S A. 1992
  5. Kontos HA. Analysis of vasoactivity of local pH, PCO2 and bicarbonate on pial vessels. Stroke. 1977.
  6. Lohr NL. Enhancement of nitric oxide release from nitrosyl hemoglobin and nitrosyl myoglobin by red/near infrared radiation: potential role in cardioprotection. J Mol Cell Cardiol
  7. J Appl Physiol 1985. Joyner MJ. Nitric oxide and vasodilation in human limbs.
  8. Expert Opin Pharmacother. 2001 The role of nitric oxide in penile erection. Cartledge J.
  9. Pharmacol Ther. 2005. Nitric oxide and penile erectile function. Toda N.
  10. J Clin Hypertens 2006. The role of nitric oxide in erectile dysfunction: implications for medical therapy. Burnett AL.
  11. Carbon dioxide enhances nitration of surfactant protein A by activated alveolar macrophages. Sha Zhu. 2000.
  12. Erectile Dysfunction in Patients with Hyper- and Hypothyroidism: How Common and Should We Treat? GE Krassas – ‎2008.
  13. Effects of hyperthyroidism, hypothyroidism, and thyroid autoimmunity on female sexual function. A Oppo – ‎2011.
  14. Hyperprolactinemia and Erectile Dysfunction. SI Zeitlin – ‎2000.

25 thoughts on “Red Light Therapy Treats Erectile Dysfunction

    • Joe says:

      That’s one broad spectrum source that also outputs a lot of heat too. It’s hard to know how many mW/cm2 of bioactive light will actually be hitting your skin from those though.
      LEDs and lasers are the most well studied narrowband sources.

  1. C Smyth says:

    When you say “apply directly”… What do you mean? What’s the distance of the light to the tesicles ? I have a low heat LED light.

      • Joe says:

        The distance you should use the light depends on the power density. The distance that gives between 20 & 200mW/cm² is most appropriate according to studies.
        You can measure the power density of your light with a solar power meter for example.
        When you know the correct range, just point the beam of red light onto the naked testes.

  2. Bill says:

    I am a very healthy 74 year old male who is married to a beautiful women for over 52 years (we like each other) We are both still working full time in our own business. Problem 1; 3 years ago I was diagnosed with high risk prostate cancer, I had hormone therapy (testorone blocker) and 10 weeks of radiation. Cancer is in remission, I feel fine, like to work. Problem 2; have a hard time getting an retaining an erection. I don’t like the pills and the injections are too expensive. We just happen to own a Skin Care Spa. In this Spa we own several LED light machines. When we bought them we did our research and they are the most powerful LED devices available for Skin Care. 4200mw/cm2 7.2 joules per second, with a lamberton lens and a high pulsation rate, We have seen remarkable anti aging results on the skin as well as for pain relief. We have also used it for other things that we won’t say because it is way out of the scope of our license, (reversing baldness, and reversing some eye conditions to name a few) I just thought of this for ED a few days ago and found this web site. What do you think my dosage should be. Since I have just started applying this, I have no results to report.

    • Joe says:

      Hey Bill, thanks for the comment. 4200mW/cm² sounds mental – that’s way over the range in any study I’ve seen – 10 to 20 times more. Have you got a link to that product? Is the 4200 figure at a particular distance from the light source?
      I’m not sure of the best dosage exactly for ED. It sounds like you have other factors at play that are working against erection, such as the testosterone blocker you mention and just age in general. I would probably start at around 50 J/cm² per day anywhere around the groin area. You could also try infrared to get a better penetration, reaching that deeper tissue.

      • Bill says:

        Go to it has different settings also it has infra red built into it. The hand held piece attaches to a console that has the control settings. It is a pretty pricey device. ($5 to 10k). We have been using it for over 10 years. It is the standard in the skin care industry, nothing else touches it. It works like a miracle for Plantar Fasciitus. a couple of times a day for ten minutes, gone in 2 to 3 days. Have seen results for shingles as well, especially the pain after the blisters are gone.

        • Joe says:

          Thanks Bill. Which one is it you have? They don’t have any specs on the site. One product mentions 22mW/cm2 peak output, which is on the very low end of the effective densities, but it doesn’t say at which distances from the LEDs that is. There’s no way any of those products output 4200mW/cm2, because they obviously don’t have the heat management (fans/heat sinks/ etc) which would be required. You would need something that uses around 300-500 watts with that light funneled into a small treatment area to reach those ultra high densities.
          Ten minute sessions for skin treatment implies a weak device. The wavelengths they use in general seem off too. 940nm infrared for example is about 100nm higher than you want, since above 900nm it is getting blocked by water and barely being absorbed by cytochrome. 625nm is good but I think 660 or 670nm wavelengths would be better for ED.
          $5-10k for any of those seems like daylight robbery. I don’t doubt you can get an ROI if using them in a clinic and charging clients per session, but the production costs for anything on that site is probably at max about $60.
          You can measure the power density yourself with a ‘solar power meter’ and I recommend you do. Measuring the watt consumption from the wall is also a good way to know.

  3. jocelyn says:

    Wow! I haven’t thought of red light as a way to treat impotence. I’m just curious, how effective is this treatment? Of course in any treatment, there is also some failure rate. How about in red light treatment, how many percent of men are expected to not respond to this kind of therapy? Thanks.

    • Joe says:

      It’s probably the best ‘natural’ type of treatment out there for ED.
      I wouldn’t describe any application as a ‘failure’ even in extreme cases as it is always contributing to health on the cellular level, even if a few sessions doesn’t fully cure the impotence.
      Large doses of red or near-infrared light anywhere on the body help with vasodilation (via CO2 and NO mechanisms) which is always going to have some positive effect on impotence.

  4. FVP says:

    Eureka! I’ve been researching this for treating Peyronies Disease. Correction, it’s not a disease, it’s a condition. Plaque forming due from trauma. I fell from rooftop while Harnessed. Harness worked, my pants pulled where penis was most vulnerable. Been using Castor Oil which has been beneficial. Somewhere there was a claim about red light therapy. They didn’t provide any more information since Blog was old and comments where closed. I’ve wanting to build something for genital area using led lights. Can hurt any worse than I already am LOL

    • Joe says:

      Sorry to hear about that man. Sounds very unlucky and painful. Since this issue involves scar tissue, it would have been better to use red light as soon as possible after the injury, helping to encourage healing without scarring.
      Now that you already have scar tissue, changes and results will be a lot slower, but it’s worth applying around 50mW/cm2 of red or NIR light every day for 5-10 minutes.

  5. Jose says:

    what is the best training schedule in order to achieve the best results? and how many times a day?
    Is the red mini 670 enough to start applying?
    When could I expect to see the first results?

    Thank you

  6. Ralph says:

    Hi Joe: I just received my mini 670, my question is similar to Jose’s above. What distance from the testes for a mini 670? The paper included said very close or touching for other applications. When I get that close to the testes they get warm but not hot from the light. Is that OK? Exposure times for that distance? Thanks very much

    • Joe says:

      For improving testosterone/fertility in the testes, I would use that light from 15cm+ away, for just a couple of minutes a day, ensuring absolutely no warming or heating effect.
      For ED, I would use it on various parts of the body, again from 15cm away, but for much longer periods.

  7. wyatt says:

    Red Mini 670 for ED and other treatment areas? Using the Red Mini 670 on the face and eyes you mentioned getting red blockers but keeping your eyes closed will work in the short term. Will using the red light tighten skin and boost collagen production? If you do not use red blockers are there potential long term consequence of using in eye area at a distance?

    • Joe says:

      Hi Wyatt,
      red light is good for the eyes, helping with various conditions such as cataracts, amd, etc. Some studies even show it will improve general visual acuity. So the long term consequences are improved vision.
      It will help will skin health and function too, yes.

      • wyatt says:

        Thanks Joe!
        If I keep the light 10 inches away or so, is that ok to do without eye protection on the eyes?

        • Joe says:

          Yep, and even closer is ok without eye protection. You only really need eye protection for laser light products (due to the way to lens in your eye can focus the laser beam), but not for red/infrared LED products.

  8. Dave says:

    What about sun exposure? When is red light emitted from the sun? at all times? only at dusk/dawn? I bought tan-through shorts that allow light to penetrate them but I’m not sure if red light penetrates them or not…so a lot of questions here…

    • Joe says:

      Sunlight is a mixture of all visible colours. Red light does come from the sun at all times, but in different proportions at different times of day. An effect called ‘Raleigh scattering’ in the atmosphere filters out the sun’s blue light, spreading it across the sky.
      At dusk/dawn the sunlight has to travel through more atmosphere to reach you, so there is less blue and more red. At midday, sunlight travels through less atmosphere to reach you, so there is relatively more blue.
      Blue light and heat are detrimental to the testes so I would not advise exposing them to sunlight for long.
      ‘Tanning’ occurs with the lower UV wavelengths. Red light actually does not tan you and protects you from UV induced skin damage.
      If red light or the other visible wavelengths could penetrate your shorts in any significant way, you would be able to see through them.

    • Joe says:

      This is our most popular for using on the scrotum area –
      However many people have noted that long use of either red or infrared light anywhere on the body will improve potency, most likely through the release of nitric oxide into the blood and the increase in CO2 production, both of which have effects on vasodilation.

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