Anyone can reach peak brain performance. I feel so passionately about this that I’ve written a book called Head Strong. It’s all about hacking diet, sleep, light and many other aspects of your biology and environment. The goal: to give you the tools to create a strong, alert, resilient brain no matter how old you are.

“I have come to believe that high-performance brains are our birthright as humans.” — Head Strong

Brain fatigue and decline are not genetically pre-destined. But you do need to take steps to guarantee your biology and environment are working for you not against you.

One of the keys to brain performance is light.

For over a decade, I’ve been using light to hack my brain function, energy, skin, and sleep, but I’ve been hesitant to talk about it on the blog. The main reason is that we still don’t fully understand why a lot of light hacking works.

Using light definitely affects your biology, though — so much so that you can harm yourself with light. I’ve done it. So here’s my disclaimer: We’re going to be talking about shining specific spectrums of light into your eyes and onto your brain, as well as onto your skin and muscles. Consider working with someone who does this stuff for a living. There are neurologists and people who work with traumatic brain injury that do this stuff. I tried a light-based brain hack once and spoke in garbled words for 6 hours afterward. For a minute there, I thought I’d lost my ability to speak. You can fry your neurons with simple, non-heating LEDs. I also got a second degree burn on my leg from a non-heating LED. It’s not a heating effect, it’s a biological effect. The same thing that makes these hacks so powerful also makes them dangerous. So, please, use this stuff responsibly.

And now, let’s examine (and maybe even reverse) a few widespread beliefs about light -from the lighting in your living room, to the fluorescent lights in the grocery store, to the sunlight you’ve been taught to fear.

Light can help (or hurt) your mitochondria

“After all of these years as a professional biohacker — spending hundreds of thousands of dollars hacking my biology and traveling to the ends of the world to seek out the most cutting-edge, extreme, and ancient hacks for improving human performance, I was surprised to learn that it really all comes down to our mitochondria. I never would have imagined the extent to which these billions of tiny bacteria that live in all of us are calling the shots, controlling our energy, brains, and performance and basically determining who we are.” — Head Strong

As a scientific community, we’ve learned a lot. As a scientific community, we’ve learned a lot about mitochondrial function just in the last five years. These little powerhouses produce the cellular energy that keeps your body running, all in the form of adenosine triphosphate (ATP). Your brain, your heart, and (if you’re a woman) your ovaries contain the highest concentrations of mitochondria, with 5–10 times the mitochondria per cell than you have anywhere else. But mitochondria talk to each other all across your body, so when some mitochondria suffer, they all suffer, and when you support them, your entire body feels the difference.

Light is a nutrient that plays a significant role in signaling your mitochondria to do things and when to do them. And different light frequencies trigger different signals in your cells. Meditation, deep breathing, neurofeedback — you can improve all of these by strengthening your mitochondria, and mitochondria rely on light.

Let’s look at the most powerful mitochondrial light hacks out there and exactly how you can use them to your body’s advantage.

Light Hack #1: Sunlight for vitamin D and hormone balance

The best and most efficient light hack out there is free and accessible to nearly everyone: the sun.

The sun gives you a full spectrum of light — the same light our bodies evolved with, as opposed to the damaging white LEDs and fluorescents in most building, which lack many of the spectrums that contribute to biological function.

Vitamin D

Sunlight is the biological signal that triggers vitamin D production in your body. “But Dave,” you may say, “I can just take a vitamin D supplement! And what about skin cancer?!”

Vitamin D supplementation is great. I do it. But sunlight not only contributes to the direct formation of vitamin D in your body; it also activates vitamin D by turning it into vitamin D sulfate. So, you can be supplementing with sufficient amounts of synthetic D, but you’re still not getting the full spectrum of benefits because only sunlight can produce vitamin D sulfate.

Plus, vitamin D in supplement form can build up to toxic levels in your body [1]. You’ll never overdose on vitamin D from sunlight — you stop producing it when you hit the optimal level. You might get a sunburn, which stings and correlates with skin cancer, but you can easily avoid it by staying in the sun for 10–20 minutes at a time, and then putting on a quality sunscreen (or you can take astaxanthin to keep yourself from burning). You can read more about the risks versus benefits of sunblock and sun exposure in this article.

There’s more to the story than sunburns, folks. For instance, unexposed skin — skin that rarely sees the sun — carries a higher risk of skin cancer. Frankly, I think that sunscreen companies and studies founded by cancer foundations are misleading about melanoma’s relationship to sun exposure.

That said, there is a very real correlation between UV rays, sunburns, and skin cancer. But over the last couple of decades, Westerners obsessively block UV rays with UV-filtering windows, windshields, sunglasses, and sunblock. And I think that’s to our detriment. For instance, wearing a sunscreen with a sun protection factor of 30 reduces vitamin D synthesis in the skin by more than 95% [2].

UV light is powerful and there is a valid connection with cancer. Overexposure can lead to sunburns, which can cause cancer, sunspots, and wrinkles. Overexposure to your eyes can cause permanent eye damage, but this doesn’t mean you should avoid it entirely. It’s all about finding the right dose: 10–20 minutes of direct sunlight, on as much of your body as possible, every day. Your body requires some UV light to work properly [3,4].

Cholesterol sulfate

You also need sunlight to produce cholesterol sulfate from cholesterol (eat your butter!). Your body uses cholesterol sulfate as a precursor to all your sex hormones. You need sulfate for these reactions as well (egg yolks!), and direct sunlight to catalyze these reactions.


Sunlight also contributes to optimal testosterone levels [5]. Testosterone is a major hormone for both men and women. It dictates your muscle tone and body composition, your confidence, and your sex drive.

Nitric oxide

Nitric oxide (NO) is a signaling molecule in your body that causes vasodilation, or the widening of your blood vessels. You want NO because it prevents heart attacks and improves athletic performance and recovery. Ever heard of beets or beet juice as a pre-workout supplement? The nitrates in beets increase blood and oxygen flow to your muscles, enhancing performance and increasing your endurance. Sunlight also increases NO levels in your body [6].

Better blood flow means more oxygen and nutrient transport through your body and efficient removal of cellular waste. That’s also how NO lowers your blood pressure and decreases inflammation.

Endorphins and dopamine

Sunlight also helps you relax and destress through the release of endorphins [7].These hormones can also help reduce pain, support hormone regulation, and even inhibit cancer growth [8,9,10, 11, 12].

Sunlight also increases dopamine release and dopamine receptors in your body. This is good news if you suffer from depression or seasonal affective disorder, which suggest low levels of dopamine, and even Parkinson’s disease, where dopamine neurons are damaged [13]. Higher dopamine levels also mean you’ll have more motivation and will be less prone to addictive behaviors. Before Prozac, doctors would send depressed people and alcoholics to solariums — buildings with glass walls and ceilings. The dopamine from the sunlight would boost mood and ease withdrawal.

How to use it: Get at least 10–20 minutes of pure sunlight (no sunblock) on your bare skin every day. If possible, do this from about 10:30am-3pm when UVB rays are most powerful. Naked is always better. Sunlight on your chest and back will increase testosterone in men 120%. Sunlight on your testicles can increase production 200–400%.

The D Zone

For everyone else, you may need to add a narrowband UVB light, in addition to your vitamin D supplement.

Light Hack #2: Get a narrowband UVB light

You can get many of the benefits of natural, full-spectrum sunlight from a sun lamp or tanning bed that is high in UVB waves. UVB (as opposed to other ultraviolet rays) cause less tissue damage and offers more biological benefit. UVB exposure can increase your vitamin D production, decrease inflammation, trigger the production of happy-making neurochemicals like dopamine, and can help get rid of skin issues like psoriasis or acne [15]. UVB lamps also kill antibiotic-resistant bacteria and, in some studies, even protect against skin cancer [16,17].

UVB has the same power that the sun has to sulfate vitamin D, which you can’t get from supplementation alone. That’s why I recommend using a UVB tanning lamp (again, preferably naked) during the winter if you want to perform at your best and have the most resilience against stress and infection [18].

How to use it: The most therapeutic wavelength of narrowband ultraviolet UVB light is 311–313 nanometers. Use a UVB lamp or UVB-heavy tanning bed for 5–10 minutes, twice per week, to get the same benefits you would from taking a vitamin D supplement, and more [19]. UVA is the wavelength that’s responsible for sunburn and contributes more to signs of skin aging, so you definitely want less, but there are benefits to having access to a full spectrum of light, so a little is OK. You can avoid exposing your face and neck to this light and concentrate it on your body if you’re worried about wrinkles.

Light Hack #3: Expose your eyes to light

Your eyes also respond to UV light, but in a totally different way. A little bit of sunlight in your eyes increases melanin — the same protein that gives you a tan — and more melanin in the eyes affects all sorts of performance-related markers. Melanin is an insulator for electrical connections between cells in the brain, which means that more melanin allows signals in the brain to move faster. This may mean faster reaction times, improved thinking ability, and of course, light sensitivity. People with lighter eyes are way more sensitive to bright light than those with more pigment.

How to use it: Go outside in the morning or mid-afternoon sunlight and look at the sky for a couple of minutes. Do not look directly at the sun, just the bright sky. If you live in a place that stays pretty cold and dark in the winter, you can do this with your narrowband UVB light. Now, for the sake of disclaimers, I’m not telling you to do this, but instead telling you what I do. And I stare at my UVB lamp without sunglasses for a couple of minutes per day to increase melatonin production. I can tell you it gives me a ton of energy and makes me feel pretty great. If you decide to do this, take off your glasses or contacts to optimize melanin production.

Light Hack #4: Embrace total darkness

This is another eye hack that affects these little light receptors in your eyes called melanopsin.

Melanopsin sensors inside your eyes have nothing to do with seeing. Instead, they act as circadian controllers. These guys will change your entire circadian rhythm in response to blue light — even in blind people, which is how we know this has nothing to do with visual processing [20]. Melanopsin is the reason you want to avoid blue light after the sun has gone down and sleep in a completely dark room.

How to use it: If you want to invest in one hack that will seriously change your life, invest in blackout curtains. The darker the room, the better you’ll sleep. In fact, I carry electrical tape with me when I stay in hotels (which I do often) so I can tape over the omnipresent blue LEDs that ruin my sleep.

Wearing an eye mask can protect the melanopsin sensors, but remember that your skin is photosensitive, too, so total darkness is better. Plus, eye masks are uncomfortable and can come off in the middle of the night.

Light Hack #5: Better focus with light and color

Helen Irlen is a dear friend and a pioneer of light and color therapy for people who have trouble with visual processing. You can get deep into her work in this podcast. She talks a lot about Irlen Syndrome or Scotopic Sensitivity Syndrome, which affects about 48% of the population. When you have Irlen Syndrome, your brain struggles to process visual information and spends a lot of unnecessary energy trying to see well. Irlen Syndrome can make it really hard to read or can totally sap your energy when you’re under certain light.

How to use it: Find an Irlen Syndrome practitioner in your area to determine if you suffer from scotopic sensitivity and which tints increase your energy and performance. You can get glasses made with a custom tint for your eyes.

Light Hack #6: Avoid junk light

Get rid of your white LEDs and compact fluorescents. Newer artificial light bulbs lack many of the sun’s frequencies that our bodies and brains need. With artificial lights, we’ve eliminated most of the infrared, red, and violet light found in natural sunlight, and we’ve amplified the blue light beyond anything we have evolved to handle — most LEDs and compact fluorescents emit about 5 times the blue light we’re used to.

When your eyes have to function in unnatural spectrums of light, it stresses (even damages) your mitochondria, slows down your ATP (energy) production, and increases free radical production. This hurts your mental performance big time. Mitochondria communicate with each other so any stress to the mitochondria in your skin or your eyes can affect the mitochondria in your brain, your heart, and everywhere else in your body.

How to use it: Switch all the lights in your house to halogen and incandescent. They aren’t perfect, but they’re better. You white LEDs might be saving a little bit of energy, but they’re junk light.

Light Hack #7: Use red light for pain, inflammation, and skin

Red light is amazing at recharging your mitochondria. Red light can also stimulate DNA and RNA synthesis, activate the lymphatic system and increase blood flow, which is good for carrying waste from the body and repairing damaged tissue. It can even decrease inflammation and swelling, all the way down to deep tissue.

That means more energy, less pain, and things like faster wound healing. Red light donates photons to your mitochondria via molecules called cytochromes, which allows them to make even more ATP for energy. This provides you with steady energy all day and better sleep at night.

Red light also triggers collagen synthesis [21]. More collagen means fewer wrinkles and supple, younger-looking skin.

How to use it: Install red lights in and around your home and use them in the early morning, at night, and therapeutically for an increase in mitochondrial function and collagen production. I have a red light strip installed over my bed that I use at night to do just that.

Even very weak red lights can be powerful when you shine them over an injury. There are red lights on Amazon for as little as $6. Simply hold the light over the injured area for a couple minutes per day. If you do try something like this over a certain part of your brain, please don’t go over a minute. Move it around to increase blood flow and mitochondrial function throughout. You can also find LED colored lights with a brightness and color remote controller. This lets you switch from blue to red, depending on what time of day it is.

For collagen synthesis, a couple minutes every day in front of a red light could significantly improve your skin’s tone, texture, redness, and signs of wrinkles and fine lines. You can also find medical-grade LLLT practitioners for a heavier dose of light [21].

Red light may also stimulate hair follicle growth to reverse hair loss and even baldness. We could use some more research here, but initial results are promising [22].

Light Hack #8: Low-Level Light Therapy (LLLT)

Low-level light therapy or LLLT is like a more intense version of sitting under a red light. This is a cold laser that concentrates light to one area on your body.

Athletes use LLLT for better athletic performance, probably because it increases strength and speeds up muscle recovery [23]. It also helps to heal infections post-surgery, relieves chronic and acute pain (especially in your joints), and decreases inflammation [24,25,26]. LLLT increases energy by stimulating mitochondria and boosting ATP production and blood flow [27,28]. And it contributes to healthy skin by healing scars and burns and decreasing UV damage [29]. Lasers shrink nerve inflammation, so putting an LLLT 3–4 inches above your belly button, right below the rib cage, can help with stomachaches and nausea, as well as an inflamed gut.

How to use it: You can find a practitioner that uses LLLT or buy one yourself. The medical-grade lasers are pretty expensive, but consumer-grade LLLT units run anywhere from a couple hundred to a couple thousand dollars. I don’t have a specific recommendation for this one, but there are a ton on the market.

Light Hack #9: The PhotonWave

These might be a little harder to find, but I have one from a chiropractor friend of mine. PhotonWaves, also known as Rainbow Light Stimulators, are made mostly in Europe. You use a PhotonWave to create a very narrow spectrum of pure color for therapeutic purposes. Each color does something different (the device comes with a manual that details each color). You then hold the PhotonWave to your face and stare at the mono color of light, which makes EEG-measurable changes to your brain, lighting up areas that are usually dark. PhotonWave is especially effective for autism and bipolar disorder.

How to use it: Find a practitioner that uses color light therapy or look for a PhotonWave device for yourself.

Light Hack #10: Add infrared light

Sunlight has infrared light, but you won’t get any of it from indoor lighting. You can’t see infrared light, but you can feel it; you experience it as heat, and it supercharges your mitochondria.

You can get infrared light, which triggers even more energy production from your mitochondria in your eyes and skin, with a healthy dose of sun exposure, in incandescent bulbs (in very small amounts), or with an infrared sauna. Increased mitochondrial function, again, is going to increase blood flow, which is great for nutrient and oxygen transport and also speeds up detox pathways. This is why people are obsessed with infrared saunas.

How to use it: Switch all the bulbs in your house to incandescent, which emit a small amount of infrared. Find an infrared sauna with full-spectrum, near-infrared light. You also want to find one that emits low to no non-native EMFs.

Your day in light hacking:


In the morning, you want to tell your body that it’s time to wake up. Brighter lights are best and blue light, in particular, can help shut down melatonin production and raise your energy for the day. Sunlight is always best because of its full spectrum of light and color, but for those of us in the Northern Hemisphere in the winter, a normal white light is fine. I turn on a 500-watt halogen light in the morning, mounted above my desk, to tell my body it’s time to wake up.

Halogen lights are the most like natural sunlight, although they’re not full-spectrum. You can also expose yourself to some brighter red lights for a few minutes in the morning for a mitochondrial boost.

During the day

Your body gets confused when you’re inside all day under artificial lighting. Artificial light is a recipe for eye strain, fatigue, and, if you’re under it after sunset, a disrupted circadian rhythm. This is especially true of fluorescent lights, which I won’t even allow in my house. They’re junk lights that offer zero benefit. To prevent daytime sleepiness and keep your circadian rhythm in sync, go for a walk, take walking meetings, or set up a full-spectrum light or a simple halogen light in your workspace. The trick is to dim the light slowly with the setting of the sun, so your body gets the signal that it’s no longer the middle of the day. On the other hand, you can trick your body into thinking it’s earlier or later, depending on the brightness of the light. That’s useful if you’re pulling an all-nighter or combating jet lag.

Using bright white or blue lights in the morning when it’s still dark outside will shift your wake time earlier. Using them in the evening will shift your bedtime to later.


This is when you want to block all the blue light you can. Blue light disrupts melatonin production for up to four hours, which will make it a lot hard for you to get to sleep and stay asleep. Not just that. Many studies have linked late-night exposure to light to some really unpleasant things, like obesity, breast cancer, prostate cancer, diabetes, heart disease, and more.

Here are a few nighttime light hacks:

  • Turn off bright lights before bed
  • Stop using compact fluorescent lights (those curly bulbs). They give off unhealthy amounts of blue spectrum and cause eye strain
  • Switch to amber or red bulbs, which have no blue spectrum
  • Wear orange-tinted glasses (not the sexiest item in my wardrobe, but they make a big difference)
  • Stop staring at bright screens for two-plus hours before bed (either skip screens entirely or download f.lux for free)
  • Black out your sleeping area by taping over or unplugging LEDs

When I first did all of the above, the difference was profound — better, deeper sleep. (Disclosure: I do lots of other sleep hacking things, too.)

Have you played with light hacks? Did I miss any? Let me know in the comments. Thanks for reading and have a great week.































Originally published at on December 4, 2016.

Originally published at


  • Dave Asprey

    Founder of Bulletproof, Author of “Game Changers,” bestselling author of "The Bulletproof Diet," biohacker

    Dave Asprey is the founder of Bulletproof 360, Inc., a leading-edge food, beverage, and content company, best known for the widely popular Bulletproof Coffee and starting the fat for fuel movement. He is a two-time New York Times bestselling science author, host of the Webby award-winning podcast Bulletproof Radio, and has been featured on the Today show, CNN, The New York Times, Dr. Oz, and more.

    He’s a self-made master of biohacking – a term he coined and has been recognized for creating in the Webster Dictionary for a concept he’s spent years testing on his own mind, body and brain. Over the last two decades, Dave has worked with world-renowned doctors and scientists to uncover the latest, most innovative methods for enhancing mental and physical performance by taking control of his own biology. The results speak for themselves: Dave has boosted his IQ by 20 points, dropped 100 pounds without dieting, and launched the Bulletproof empire including his unique line of health products, popular podcast and New York Times best-selling books. Dave has helped hundreds of thousands of people perform at levels far beyond what they’d expect, and without burning out, getting sick, or allowing stress to control decisions. Check out his new book "Game Changers" here.