For the past few weeks, I’ve been sticking music headphone-style plugs in my ears for twelve full minutes every morning shortly after waking up. Not for listening to music, mind you: they are Valkee plugs, and they shine a bright light directly on part of my brains.

Why the hell am I doing that, you may be inclined to inquire. Well, first of all, because I got them for free – a limited edition, no less! – after the recent Slush conference in Helsinki (Valkee is a Finnish company).

Secondly, the bright light plugs are designed to, according to Valkee’s website, “maintain your energy levels, keep up the good mood, reduce need for excess sleep, and fight cravings for sweets”.

Well, I’m certainly sleep-deprived and in need of more rest, with all the traveling and starting a new business and trying to ensure our nearly 3-year old survives yet another day. I certainly have way too many cravings for sweets. I definitely have trouble maintaining my energy levels.

All I really have going for me is a good mood, at least most of the time … I think.

And thirdly, I figured it simply wouldn’t hurt to give Valkee a shot. I was right – but is that enough?

The science behind Valkee


With its MP3-player resembling devices, Valkee offers on-demand, in-ear bright light therapy. This exists because, apparently, people are increasingly suffering from reduced exposure to daytime light, for a variety of reasons (shift work, long-distance travel and whatnot).

On its website, Valkee explains it thusly:

Reduced daytime light causes many problems: from winter blues, mood swings and general fatigue to anxiety, sleep deprivation, carbohydrate cravings, and dampened spirits. These symptoms usually appear in the autumn and winter months when nights are getting longer and daylight is scarce. People who work in light-deprived environments or as shift workers during the night can also suffer from similar symptoms.

To improve people’s moods, sense of well-being and raise their energy levels, Valkee suggests buying its headset – the ‘Valkee 2’ costs 199 euros and comes in two colours, black and silver.

Now, this isn’t a scam. Valkee’s products are the result of long-term scientific research and development work, in collaboration with Finland’s Oulu University, and its bright light headset has been clinically tested and is a certified medical device in European class II(a) for treating and preventing seasonal affective disorder (SAD) or “winter blues”.

Valkee claims its headset “relieves SAD symptoms like tiredness, anxiety and reduced cognitive performance” and that, in a clinical trial, “9 of 10 participants suffering from severe SAD symptoms experienced a total relief”. All this and much more about the science behind Valkee can be found on its site, and the company relentlessly puts out press release after press release to prove its worth.

Last June, the Finnish health tech company raised 7.4 million euros in Series A funding (PDF), from investors including Mérieux Développement, the investment arm of giant French industrial group Institut Mérieux. They later strengthened their board with Mérieux partner Valérie Calenda.

The company is also backed by Esther Dyson, Nokia’s former director Anssi Vanjoki, Jaiku co-founder and ex-Googler Jyri Engeström, and Lifeline Ventures.

That’s all fine and dandy, but here’s the problem: how can I, as a consumer, reliably measure the results and seriously evaluate the effectiveness of Valkee’s bright light headset?

What I’ve discovered after using Valkee intensively the past few weeks

Well, practically nothing.

That’s not to say the headset isn’t a perfectly adequate and worthy clinical device – it’s just that it’s nearly impossible to truly measure the effects as far as I’m concerned.

If I sleep more, or better, I’ll likely feel more rested. But how can I tell this is because of using the Valkee 2 device, or simply because my sleep was better for different reasons?

If I feel more energetic than usual, do I have to thank Valkee for that, or is it simply a result of multiple factors that have nothing to do with the bright light therapy?

If I crave less sweets today than most days last week, is it because I’ve been using the Valkee headset, or because my wife repeatedly told me I should be watching my weight?

If I’m more upbeat than usual, is it because of the 12 minutes of bright light beamed onto my brain every morning, or because somebody said something nice about me or what we’re doing at, or because my young son was extra cheery and animated today?

I hope you see where I’m going with this: when you live a life with irregular sleeping patterns, travel and other factors (such as the stress and excitement of embarking on a new venture), your quality of sleep, energy levels and mood will depend on a lot of things. Plain and simple, I don’t know whether Valkee is just one of those things, the main contributing factor, or if it doesn’t have any effect at all.

This, I believe, is Valkee’s biggest mountain to climb. They may be able to scientifically prove that their headset does what they say it does, but if someone is going to pay 200 euros for a device, they’re going to have to notice and feel this for themselves. For the record, some do.

Turns out I may simply be too healthy (go figure)


I presented this problem to Valkee CEO Pekka Somerto (picture), and he delivered:

Of all Finnish people at these latitudes, 40% suffer from some degree of Seasonal Affective Disorder.

At its least, it’s subsyndromal winter blues, and in its more severe form it’s real depression. The symptoms are those that you’ve tried to pay attention to and observe in yourself, too: too much sleep, low energy, depressed mood, craving for carbs.

But, if you’re not suffering from the condition – and 60% of Finns aren’t – you won’t really experience relief from them either.

Analogous with “if you don’t have a headache, how do you know if Aspirin is working or not?”.

The further south you go from Finland, the smaller the prevalence of SAD is, but it is still to the tune of 25% of the population in the Northern parts of continental Europe.

At the end of the day, it sounds like you may be a basically healthy person who does not suffer from SAD and does not need the cure for it either. Not everybody does.

I also asked Somerto whether this means there may not be enough of a market for Valkee to build a huge business, to which the affable chief exec responded:

Of the total European population, the estimate (sources are available if you need) is 17.8%.

For a business, the bigger challenge than geography is the strong seasonality of winter blues. The “high season” lasts just 3-4 months of the year and we’re in the middle of it now.

Somerto also said winter depression is a global phenomenon, and provided me with this map/graph:



I’m going to keep plugging in the Valkee 2 headset every morning for a full twelve minutes, because I figure it won’t do any harm, and if the positive impact is really there, then all the better.

But I still don’t know whether Valkee works for me, and I’m positive I wouldn’t pay 200 euros for the headset if that continues to be the case.

Full disclosure: as mentioned in the beginning of this article, I have received the Valkee 2 headset (price: 199 euros without eventual shipping costs) free of charge to try it out.

All images used above courtesy of Valkee.

  • Juhe Leinivaara

    Valkee has been the topic of much debate here in Finland. They present their studies in way more positive light as they actually are. They’ve made strong claims before publishing any data. In short, the scientific reseach into the efficacy of Valkee’s earlight is still lacking, years after they have been selling their product.

  • Valkee Ltd

    The clinical efficacy data and patient safety of the Valkee bright light headset product have been duly and thoroughly appraised by the completely independent EU Notified Body who approve such Class 2 medical devices, and have been confirmed to fulfill all requirements for such medical devices on both accounts (as well as for the medical device manufacturing quality system). Most recently this EU Notified Body assesment was completed for the introduction of the new Valkee 2 product reviewed here. Wider publishing of study data, by the way, is not a requirement for medical device certification and registration – only sharing it with the regulator is – to be precise. We have been exceptionally transparent in also sharing study findings early on. Some have since then been peer reviewed and published; some are now in review. The website Leinivaara refers to is published completely anonymously, and it appears to be maintained for clearly and only a malignant purpose. Its claims regarding Valkee’s work are fabricated, and a clever mix of mostly utter fiction scantly clad in thin fibers of reality.

    • Esa Turkulainen

      So how would you reply to the the assertion that your ONLY placebo controlled study showed no effect ( How would you reply to the Swiss study that showed NO subjective increase in alertness, NO improvement on psychomotoric vigilance and NO effect on circadian rhythm ( And no, do not hide behind “they confirmed our hypotheses about monoamines being the key”, the study reaches far beyond melatonin.

      Your studies are either not properly controlled or do not show any effect when they are properly controlled.

      Please explain this glaring disparity between your (and others’) research and your bold marketing claims.

      • Valkee Ltd

        The first fully placebo-controlled double blind study setup for any
        bright light device was created in mid-2012, and has been used in all of
        Valkee’s clinical studies since then. The first completed and reported
        result with that setup is on acute treatment of anxiety, and the result
        was a strong positive finding (test vs control group) with statistical
        significance (P=0.048 for absolute values and 0.024 for relative

        The 2010-11 study you refer to had earlier taught us something
        different but also important important about the melanopsin protein’s
        trigger threshold to light, while also confirming the earlier pilot
        study’s strong efficacy to in-ear bright light.

        The study of
        Bromundt et al (2013) demonstrated just one statistically significant
        outcome: that bright light through the ear canal did not suppress
        melatonin level like it did with through the eye. And as you point out,
        we made and reported the same conclusion ourselves a year earlier (2012): . Different from the conclusion you are implying above, the Bromundt study did not show any statistically significant
        difference between the eye and the ear in affecting subjective
        sleepiness. To discover that, one would have to read the full study

        As to the role of melatonin, others long before Valkee (e.g. Vandewelle et
        al, 2006, 2007; Phipps-Nelson et al, 2003) have
        established that light has an alerting effect also in the absence of
        melatonin, and daytime exposure to light decreases subjective sleepiness
        and increases psychomotor vigilance also when melatonin is naturally
        non-existent, confirming existence of a non-melanin-based mediation
        route, believed to be via other monoamines. This is the conclusion and one of the
        fascinating subjects of current and recent further research including at
        Oulu university and elsewhere around the world.

        • Esa Turkulainen

          Thanks for the response.

          The study you are referring to in your first paragraph has not yet been published. All we have access to is your poster presentation and that is quite not enough to determine the potency of your witness. For example in here you present the changes in patients only in percentages. This is an unusual way to represent data as it hides a lot of information, such as what where the differences between groups to begin with. Others have brought this issue up as well ( (only in Finnish)
          As such, this poster presentation is not a proof of anything, yet. I would happily see the data for myself.

          I do not understand your explanation on the 2010-11 study. The 1 lumen was set up as a placebo, and it did just as well as the 9 lumen did. Are you trying to say that melanopsin’s trigger threshold is so low that it doesn’t really matter how dim the light is as you’ll always have an effect? Please elaborate. Your claims are mighty bold if so.

          You claim that the Bromundt study did not show statistically significant differences between the ear and light treatment in subjective sleepiness. You accuse me of not doing my research properly. May I ask, have you done yours properly?

          For the Bromundt study does show a significant difference in subjective sleepiness (p=0.007). This is when a post hoc analysis is done, stripping down the data points only to the three relevant ones (baseline, before and after treatment).

          Moreover, you’ve previously claimed in your marketing and studies that Valkee’s device increases reaction times and the level of attention. When this study compared your device to a sham, no significant differences were found.

          But this whole ordeal is not only limited to the rather condemning Bromundt study. You have a history of doing studies poorly and thus having to publish them in journals that are not in any way trusted. You have previously for example paid to get your studies published in predatory journals such as WJNS (belongs to SCIRP, that is blacklisted here:

          And despite the lack of proper studies and the lack of evidence, you’ve been selling your device for sometimes serious medical conditions, for some 200 euros a piece. I wouldn’t call that very sincere.

          • Valkee Ltd

            The acute anxiety results data is presented in the poster (link that I provided) both with relative and with absolute values – you’ll find that when you read the poster. The people quoted in the Taloussanomat online article that you refer to (link that you provided) had at press time looked at only the relative changes shared in our press release, and were wondering why the absolute values were not included. They later looked at the absolute and relative data shared in the poster, and we’ve spoken with them in person since then. They had no further further concerns regarding the methods or the validity and strength of the results.

            The reaction time study (with Finnish National Hockey League Team Oulun Kärpät) was controlled and the result was positive and statistically significant. The article is currently in review. Many of the team’s players have continued to use the product regularly for the last 2 seasons since the study. The attention performance study (another dimension of cognitive performance) with Aalto University students was also controlled, and the result positive and statistically significant.

          • Esa Turkulainen

            Well then, we’ll be waiting for the full study in that case. I do hope it has everything in order.

            Everything else in my comment you decided just do dismiss. Care to explain why?

          • Juhe Leinivaara

            “The reaction time study (with Finnish National Hockey League Team Oulun Kärpät) was controlled”

            How exactly was the blinding done in this study?

          • Jay

            Quite frankly I find the author to be quite cynical… could ask the same questions about any variable factor against a fixed eg an antidepressant tablet for example. Very poor article. The device stands up against this poor degree of interrogation.

          • editor

            Hi Esa,

            Valkee has absolute values on their website in a new version of the poster. I’d also rather see the statistics, their p=0.048 is quite close to the 0.05 threshold – it may miss it when checked, who knows. Did they use percentages to get the p=0.024, which looks better? That’s not strong, you may know that “strong significance” is somewhere <0.01 or <0.001.

            It ain't even the statistics. It was very likely unblinded. Placebo was a device with the light switched off. Active earlight heats the ear canal, a well-documented effect. With GCP, participants have to be informed about possible adverse effects – they knew it. The setting, simplified:

            2 groups with moderately anxient patients; you say that active treatment heats up the ear canal. Earlight patients feel the heat, the others not. As if you would say "you got treatment – you others not". The well-known placebo effect, and only acutely measured.

            In the real placebo-controlled study patients were not able to guess their group. The primary outcome, remission, was reached in 5/31, and 4/30 persons with 4 and 9 lm earlight (17 and 13%). Placebo may have been as weak as 0.7 lm (!), it healed 8 of 28 patients, or 29%. Confirming the 77% from their pilot? That's "bold". The melanopsin "offset" was obviously not studied here.

            They're lucky without a publication: Tampering with the design, to deny the clear negative result, for economic reasons (a hokuspokus treatment): That's a possible career-stopper.

            According to Somerto at pixelhealth, Valkee's "research" takes 3 years to be published. I.e. NO article before 2016 – in what journal? The swiss study was
            "Submitted August 22, 2013, Returned for revision September 24, 2013, Accepted October 8, 2013", published November 13, in a proper journal.

            No need to comment Valkee's statement about the swiss trial further:
            My site has a malignant purpose? That is outrageous. But I think it becomes always clear, what Valkee's claims are worth.
            I will publish some two or three post-X-mas presents, at the latest 27.-30.12., to bring more light into this gloomy scam.

  • Juhe Leinivaara

    I’m game, Valkee. What are the top three studies for your product?

  • asteri0n

    2013 Study on PubMed ( suggests no benefit from “extraocular light via the ear canal”. This would suggest that any benefit is probably due to that most effective medical intervention, the placebo effect!
    I certainly can’t find any evidence to warrant spending 200 euros on Valkee’ device! Would be great to see a proper, larger scale (i.e. more than 50 subjects — preferably 100) study that incorporates ‘dummy’ headsets to account for placebo effect benefits. Until then, I suggest people seeking light therapy for their SAD purchase light box from a reputable manufacturer (Philips are good), as this is the one type of SAD light treatment that HAS been validated through proper scientific testing!

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