HumanCharger Review: Does Light In The Ear Help With Sleep, Jet Lag & SAD?


Light is extremely important (and powerful) when it comes to health, healing and happiness. Without light exposure at the right times our sleep takes a hit, our mood and energy levels plummet and we can become depressed.

But it can be hard getting adequate light exposure at the right time - maybe we're living close to the poles, or we do a lot of long haul travel, or we work odd hours meaning we can't get outside in the sun.

Fortunately, with modern technology there are solutions to this lack of light issue. One such solution is the HumanCharger which I have reviewed in detail below.

*** Update 2019 - HumanCharger have announced a new BlueTooth enabled version of their HumanCharger. You can learn more and preorder this unit on their Indiegogo page HERE ***

What Is The HumanCharger?

The HumanCharger is a small pocket sized device that shines bright white light into your ear canals.

Designed & manufactured in Finland, the company claim their HumanCharger device is a 'Sun in your pocket'. And thats exactly what it's meant to be - a portable device (note much bigger than a cigarette lighter) with a set of ear phones that make the unit look like a typical MP3 player.

But instead of playing music, this device emits light: White light, a full visible spectrum light with a peak wavelength of ~450nm.

Why would you want to shine white light into your ears? Read on.

Spot the Biohacker - Oura Ring, HumanCharger and red light panel!

Why The Human Charger Is Useful

As I mentioned in the introduction, light can have a profound impact on the body. 

We know that blue light is stimulating, suppresses melatonin and disrupts sleep (read more about this HERE).

We know that red light has healing properties and can help with recovery (read more about this HERE).

And we know that bright light exposure in the morning is important for sleep later in the day, proper hormonal function and stable energy (I cover that in detail HERE).

Having a device like the HumanCharger, that allows us to control when and where we are exposed to light creates a multitude of performance and health benefits. As I outlined in my Morning Sun for Sleep article:

  • morning sun exposure - especially light around the 400-500nm range - stimulates cortisol production (which is a good thing)


  • Morning exposure to bright sunlight helps reset our circadian rhythm.


  • Circadian rhythms do more than simply tell the body when to be asleep or awake. It also influences what hormones are released in the body and when.

  • Light exposure also signals to the body to produce neurotransmitters like serotonin and dopamine.

  • Serotonin, a neurotransmitter, regulates mood, appetite, memory and sleep. By exposing our bodies to morning sun, our serotonin cycles stay aligned with ‘nature’, peaking mid- afternoon and dropping off at night – synchronous to our body temperature and our cortisol patterns.

But not everyone can get adequate light exposure in the morning.

Maybe you:

  • Live close to the poles

Meaning you have long days and plenty of sunshine in summer, but come winter time you don't get much light at all. Plus it's cold, so you're less likely to go outdoors.

  • Do a lot of long haul travel

Jet lag, as a result of international travel is primary caused by disrupted circadian rhythms. Your light/dark cycles are heavily disrupted, and when the body expects (and needs) light, maybe it's the middle of the night in your new destination (or vice versa).

I cover jet lag in more detail in THIS article. 

  • You work nightshift

Meaning you are sleeping when the sun is up and are awake when the sun is down. You simply miss your opportunity to get your morning sunlight hit.

  • You spend a lot of of time indoors

This is the most common reason. You live indoors, you travel to work underground, you work indoors... And when you do get outside, the sun is blocked by tall buildings and your your skin, head and eyes are all restricting the amount of light your body is exposed to (from clothes, hats, glasses etc).


No doubt now you are understanding why having a portable 'Sun in your pocket' light device can be so useful in the modern world.

The HumanCharger allows one to 'trick' the body - exposing the body to the bright light that is essential for optimal health, mood, and sleep.

Better yet, its convenient - we can choose when we use it (based on our local time etc) and it's non-invasive (we simply put in what looks like conventional ear phones).

Speaking of the ear, we know that light is needed by the body, and in the articles I listed above, we know that the skin and eyes have light photosensitive receptors... but what about our brains?


Does The HumanCharger Work - A Look At The Science

I will admit - I had my doubts around the effectiveness of the HumanCharger.

Sure I understood the importance of light on the human body, but I had concerns around the effectiveness of light shining in the ear, and also whether that light signal was enough to create the change we required in the the body.

Before I experimented & reviewed the HumanCharger, I had to take a look at the science behind it's claims.

What Do We Know About The Light Source:

According to the tech specs, the Human Charger has a light intensity of 10,000 lux 1cm from the light source and has a peak light wavelength of 450nm.

This light source is from a LED light.

Human Charger state: 

The calibrated white light from HumanCharger® provides users with the daily dosage of needed sunlight in just 12 minutes per day.


HumanCharger® has a unique and patented mechanism of action which stimulates the photosensitive receptors of the brain using a calibrated white light that passes through the ear canals and ear structure.

There are photosensitive receptors throughout the human brain. When these photosensitive areas of the brain are stimulated by HumanCharger®, it affects the neural circuits in the brain via neurotransmitters (e.g. serotonin, dopamine and noradrenaline).


 I needed to know if the brain has photosensitive receptors. And if the Human Charger light (and duration) was enough to create the change necessary for the body.

Research on Light Through The Ear

Fortunately, there are a few studies looking at in ear light therapy:

  • A 2012 Paper (1) in the Medical Hypothesis titled 'Can transcranial brain-targeted bright light treatment via ear canals be effective in relieving symptoms in seasonal affective disorder?' found that yes, in-ear light therapy does help with low light conditions and seasonal affective disorder. The paper summarised:

The findings suggest that transcranial bright light therapy
might be an alternative to the traditional light therapy and should be explored in more depth.

  • A later published, randomized, double-blind dose-response study looked the same mechanism on a larger study size. The conclusion of this study read:

These results suggests that transcranial bright light treatment may have antidepressant and anxiolytic effect in SAD patients. These improvements are comparable to findings of earlier bright light studies that used conventional devices. (3)

  • Another study looked at brain activity (using fMRI) when the patients have bright light stimulus via the ear canal. The findings:

Findings from this study suggest that the brain possesses photosensitive properties, which will have interesting implications for the modulation of brain function and understanding the basic physiology of the brain (2)


Research Light and the Brain

What about shining light on the brain? Does this have any benefit?

According to these studies the answer is yes:

  • A 2017 paper published in the Journal of Neurology Research tested the impact of light on the brain in blind mice. The results showed that transcranial light illumination increases the amount of OPN4 (melanopsin a molecule used to entrain circadian rhythm)  in the hypothalamus and cerebellum. The researchers concluded:

 With this study, we provide novel information on the effects of light administration through the skull on transmitters regulating circadian rhythmicity by showing that transcranial light affects molecules involved in circadian rhythmicity. (4)

Researchers have known for a long time that transcranial (meaning across or through the skull) light affects the brains of birds and modulates their seasonal changes in physiology and behavior.

But it was unknown whether humans were also impacted by this transcranial light in the same way. That was until the 2016 paper titled 'Human Brain Reacts to Transcranial Extraocular Light' was published.

  • In this study, researchers measured brain activity of 18 young healthy subjects. And concluded:

Extraocular light delivered through the ear canals was shown to penetrate at the base of the scull of a cadaver. Thus, we have shown that extraocular light impacts human brain functioning calling for further research on the mechanisms of action of light on the human brain (5).




  • Finally, research on blind mice brains showed that transcranial light given via ear canals has a significant impact on dopamine and noradrenaline concentrations. Researchers summarised: Based on these findings, it is reasonable to hypothesize that
    light-activated molecules can also be stimulated transcranially, not only through the retina (6)


Research on Light Through The Ear on Jet Lag and Performance

We now know that light shined through the ear canal as the HumanCharger device does help with:

  • Seasonal Affective Disorder
  • brain activity
  • circadian rhythm alignment
  • and works in humans

These findings alone are a significant reason why someone would benefit from using the Human Charger. 

But what if you don't have problems with SAD. What if you get plenty of morning sunlight and have solid sleep patterns. Is there any other benefit to using the Human Charger?

If you look at these two studies, then the answer is yes - there are additional benefits:

  • Jet Lag - A randomized, double-blind, placebo-controlled study published in the journal of Aerospace Medicine and Human Performance looked at whether transcranial bright light exposure via ear canals helped with jet lag. The findings:

There was a significant reduction of overall jet lag symptoms, subjective sleepiness, fatigue, inertia and forgetfulness when comparing the TBL (in ear transcranial lights) group of 25 people to the placebo group (30 people without in ear lights) (7).

  • Agility, Accuracy & Reaction Time - The HumanCharger is not only useful for sleep, jet lag, SAD and morning sun, research has also shown that bright lights in the ear canal can help with psychomotor speed (reaction times, motor control etc) in athletes. The 2014 paper found that:

Recent fMRI findings suggested that transcranial bright light (TBL) might have
physiological effects on brain functions in humans. A total of 22 pro hockey players received either 12 min of TBL or placebo every morning between 8 and
noon for a period of 24 days. Results showed that psychomotor speed, particular motor time, improved after 24 days of TBL treatment compared to placebo in a group of professional ice hockey players (8).

In Conclusion

Based on the above peer reviewed research it is clear that the HumanCharger, despite my doubts, has some solid scientific evidence to support it's claims.

Whether you're looking for a tool to help with seasonal affective disorder, jet lag, morning alertness or to boost sporting performance, you can know that the effectiveness of the HumanCharger with it's in ear bright light white is backed by science.

What about my own personal experiences with the device?

Does The HumanCharger Work - My Own Experiences

The best answer to this question is in the video below. I recommend watching from the 12:56 minute mark as I share my review of the Human Charger: 

But if you're looking for the key takeaways, here goes:

First Time Using It

  • I used the HumanCharger once before my trip. Had slept good and done all the essentials around sleep hacks (you can see what I do to optimise my sleep here - How To Sleep Like A Sleep Coach). Plus I get a ton of morning light and day time light as I work from home, so was hard to tell if anything happened.
  • I did notice a warming sensation in the ears - this is normal I am told.
  • I had great energy during the day, but this is normal for me given the lifestyle I live.
  • So my initial use didn't create any noticeable changes. I spoke to the guys at Human Charger about this, and their response was inline with my thoughts - because I'm doing all the sleep hacks (blocking blue light, solid sleep routine, dark cold room, lots of morning sun etc) the HumanCharger may not be such a game changer to you as it may be for average Joe not doing all these advanced hacks. Plus it was only my first time using it!

Using It On A International Trip

Next up I had a massive trip, across 11 time zones and far too many flights (including one 18 hour flight with Qatar Airways that you can read about HERE). A perfect opportunity to really test the Human Chargers capabilities.

Here are my thoughts:

  • I downloaded the app and synced it with tripit 18 hours prior to my 40 hour journey. Should have done this earlier. As the app builds you a schedule so you can start using the HumanCharger to adjust to your destination time zone 3 days prior to leaving.
  • I was confused around the app recommendations. My initial thought was that you would only use this in the morning. I reached out to HumanCharger around this and they explained how the HumanCharger will help tell the body 'don't go to sleep yet'. So when I land at my destination At 5pm and my body is on 2am in the morning time wanting to sleep, the HumanCharger can help me stay awake until I'm ready for sleep based on the local time etc. 
  • I found this interesting as I had thought it would suppress melatonin. But this fear was removed when I saw the study titled Transcranial bright light exposure via ear canals does not suppress nocturnal melatonin in healthy adults--a single-blind, sham-controlled, crossover trial. The conclusion of this study was that the Human Charger would not suppress melatonin, even if used in the evening.
  • I didn't sleep that well the night before the trip - late night packing and early start for my first flight. I used the HumanCharger in the morning (as per the app recommendations ) combined with a cup of coffee. Definitely noticed an energy boost afterwards. Coffee or light??

The Human Charger app syncs with TripIt and determines the optimal time to use your Human Charger device

  • About an hour later the app informed me to use the light again. I noticed a warming sensation in my ears and again a good energy pickup. Remember - I was running off 6 hours of sleep (of which hardly any was R.E.M. sleep according to my  ŌURA ring - read my comprehensive review on that device HERE)
  • I had a 18 hour flight on Qatar Airways (worlds longest flight. Watch my trip highlights HERE). Followed by a 2 hour layover in Doha (with and excellent health centre which I reviewed here) and then a 7 hour flight to Helsinki.
  • Helsinki is 11hours behind New Zealand. So my night is there day and vice Versa. I was trying to figure out when I should sleep on the plane.

  • If the makers of HumanCharger are reading this - here's an idea for you. Include recommended sleeping (and maybe even eating?) times based on your trip in the app. Keep the app free. Add in extra recommendations regarding jet lag (I have a few articles that could help them here). In effect, turn the app a comprehensive jet lag travel app. Get it in the hands of every traveler in the world. And include recommendations to use the HumanCharger with direct links within the app so they can order the device. The perfect lead magnet. Thank me later :) 
  • Despite a lot of travelling, and some poor sleep on the flights, I landed with a spring in my step (excitement?) I continued using the HumanCharger when the app told me to do so.
  • I feel asleep rapidly each night, my Oura Ring - read my Oura Ring Review HERE - showed a good sleep latency score. This was a surprise, as I was going to bed around 10-11pm local time, which was around 9-10 AM in New Zealand. And I had only been gone for 36 hours. This was a nice surprise. Was it the HumanCharger?
  • Even though I fell asleep fast, I was waking early. Around 5am each morning. So I was getting about 6 hours sleep. I was surprised to wake at 5am, as this was around 4pm New Zealand time. I thought I would have slept in. Anyway, I continued to follow the app recommendations.
  • On the trip home I had 4 flights over 44 hours of travelling. I followed the Human Charger app recommendations and had no trouble adjusting to the time zone when I got home. I mean no trouble at all.
  • I landed back in New Zealand at 5am in the morning (which was 4-5pm Finland time). I stayed up all day, I got plenty of New Zealand sunlight (much needed after the lack of sun in Helsinki), grounded myself and used the Human Charger throughout the day.
  • Effectively I did an 'all nighter' as my body clock was still on Finland time.
  • I went to bed around 830pm that night (NZ time) and slept a solid 8-9 hours.
  • Just like that I was back in sync with the local time zone!

A New Zealand to Finland trip is probably the worst you can do for messing up your circadian rhythm. There are nearly 12 hours apart. Midnight in Finland is midday in New Zealand etc.

I must admit, I was very surprised with how quick I adapted to the local times. My first night in Finland I feel asleep at a 'normal' time of 10pm.

My first night back in New Zealand I feel asleep at a relatively normal time of 830pm.

Quite impressive given the dozen time zones I had travelled through.

HumanCharger effect? I have no way to say with 100% certainty if this was because of the HumanCharger or not. But I do know something for a fact, I was happy with how I adjusted and I will be using it on future trips!

Using It In Day To Day Life: Summer

Given all the solid research and my experiences with the Human Charger on my Finland trip, I now use it every morning.

Why not? All the research is positive, there are no side effects, and it doesn't cost anything to use it on a daily basis.

Does it help on a day to day basis? I don't know. Again, I sleep well, I have a strict sleep routine, I get lots of morning and day time light, the sun is out here in NZ, and I take a bunch of supplements to help with energy and cognitive performance (i.e. Qualia).

It's very hard to say if it's helping or not.

But I do continue to use it. And you can see how I use it in my daily Morning Routine here.

And given the study showing regular use helped athletes with reflexes and accuracy, why would I not use it?!

Using It In Day to Day Life: Winter

As I type this, we're still in Summer time here in New Zealand. I look forward to using the HumanCharger over winter time, when the days are shorter and I'm not outside as much.

Be sure to subscribe to my newsletter as I will update this section in 9 months time.


What Else You May Want To Know

  • One 'treatment' lasts 12 minutes.
  • The circle on the front glows when it's been used and it reflects time remaining in a treatment
  • You can listen to music using over ear headphones when using the Human Charger
  • You can change the light intensity on the device to suit your need
  • It is a small device, easily fitting into a pocket

  • The battery lasts around 9-12 treatment sessions
  • It takes 1-3 hours to fully recharge the battery 

How To Use The HumanCharger

If you decide to purchase the Human Charger your use may vary depending on your goal.

If you're like me, just looking for a slight cognitive boost, then use it for a full cycle (12 minutes) each morning and be done with it (until you go on holiday and need it for the jet lag).

If you live in a climate that doesn't get much sun, or you can't get outdoors in the morning, then you may want to use it more frequently in the day.

If you suffer from a mid afternoon crash, you may want to experiment using it as an alternative to coffee (though if you suffer from mid afternoon crashes, you should check out this presentation).

If you do a lot of travel, then you simple need to download the app, sync it with TripIt so you have all the flight details in there, and follow the app recommendations (note, you don't need the app to use the Human Charger).

The device comes with a useful booklet with instructions on how to use it depending on your goal. You can download a copy of this booklet HERE.

It has protocols for:

  • Health & Well Being - use for 12 minutes (1 cycle) each day within 2 hours of waking.
  • Winter Blues Treatment - use on a regular basis in the morning once a day within 2 hours of waking at the same time each day.
  • Seasonal Affective Disorder - The booklet recommends working with your physician for this. But if I suffered from SAD I would be using the Human Charger multiple times a day (while I looked at moving to a sunnier location!) Also, be sure to check out my entire article on Seasonal Affective Disorder - What You Need To Know About Seasonal Affective Disorder (SAD) Lights
  • Jet Lag recovery - If flying eastward, using the HumanCharger first thing in the morning and in early in the forenoon four times during the day at 2 hour intervals. Repeat until recovered. If flying west, use from later afternoon to evening for times a day. Or simply download the app and log your flights in there.
  • Shift Worker energy boost - Use the HumanCharger every two hours during the time you feel tired.
  • Staying up late or had an early start - Use the HumanCharger every 2 hours when you feel tired. Don't use more than 4x 12 minute sessions in a day.


Final Thoughts

Light exposure (or lack of exposure) plays a vital role in determining our sleep, circadian rhythm, mood, and health. The HumanCharger is a device that empowers individuals to access light that may be missing in their day to day life.

Not only that, but the cognitive and performance benefits of the Human Charger 'sun in your pocket' device, with its lack of side effects, mean it should be seriously considered as an every day treatment. Just as people wake up and brew a cup of coffee, I see no reason why we shouldn't wake up and shin bright light into our ears (maybe as a replacement to the coffee!)

The small, portable size, combined with the normal looking 'light buds', the short treatment time (12 minutes), reasonable price ($219), proven technology and my own personal experiences with the unit, I recommend the HumanCharger to anyone looking to improve vitality, wellness, energy, performance and sleep.

If you have any questions or would like me to expand on anything, please leave a comment below.

*** Update 2019 - HumanCharger have announced a new BlueTooth enabled version of their HumanCharger. You can learn more and preorder this unit on their Indiegogo page HERE ***

Some features of the new HumanCharger include:

  • You can talk on the phone or listen to your favorite content, even during your bright light session
  • Rechargeable with 10 sessions per charge or 16 hrs continuous music
  • Bluetooth compatible for all phones
  • You can use the new device "just" as a light device, no need to turn bluetooth on at all


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This blog post was written by Alex Fergus. Alex is a ISSN Sports Nutrition Specialist, Fitness Professional and certified Superhuman Coach who continues to expand his knowledge base and help people across the world with their health and wellness. Alex is recognized as the National Record Holder in Powerlifting and Indoor Rowing and has earned the title of the Australian National Natural Bodybuilding Champion. Having worked as a health coach and personal trainer for over a decade, Alex now researches all things health and wellness and shares his findings on this blog. Learn more about Alex's Credentials HERE.


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