The lighter side of circadian rhythms

The LIFX bulb opens up a world of possibilities that were not available with traditional light sources. It turns out you can do much more than adjust your LIFX bulbs to reflect your mood. Our friends with the dLUX Lighting Lab (check them out here) at Drexel University in Philadelphia, USA, are performing novel research with the help of the LIFX bulb. Their studies link the colour and intensity of light at different times of day with regulation of your body’s circadian rhythm.

What is the circadian rhythm? Well, have you ever noticed that you sometimes wake up before your alarm goes off? And that it happens more often if you keep a regular schedule? The reason you can anticipate your alarm clock is that you have your own biological clocks. The circadian system controls many aspects of your physiology and behavior under the direction of a master clock that operates with a period of approximately 24 hours.

To keep your body in tune, this master clock resets itself each day with the help of environmental cues. Absent any cues, the clock may drift to a period that is longer than 24 hours. The main cue that keeps everything synced is the daily pattern of sunlight and darkness, generated by the Earth’s rotation.

It turns out that both brightness and colour – amplitude and wavelength – at appropriate times of day are important in keeping the circadian rhythm in check. Among other things, light/dark cycles influence the production of melatonin, an important chemical in the circadian control system.

Living outdoors, exposed to natural patterns of daylight and darkness, humans’ biological clocks automatically synchronise to the 24-hour cycle. However, most of us reside in modern urban environments, spending the majority of our days inside. For the average city dweller, getting high levels of natural sunlight is often impractical. The dLUX team, along with many other researchers, has found this artificial environment to be inadequate for ideal circadian rhythm regulation. It is too dim in the middle of the day and both too bright and of the wrong colour in the evening.

This loss of proper tuning due to poor circadian synchronization is not without consequences. For example, researchers have associated improper circadian rhythm regulation due to poor lighting levels with a worsening of the symptoms of seasonal affective disorder, dementia, and Alzheimer’s disease. Relatively healthy individuals may also suffer from a variety of conditions, such as insomnia and lack of energy, when desynchronised. These conditions are normally remedied with various chemical stimulants and depressants, many of which have undesirable side effects.

Luckily, there is a potential alternative solution. The ability to adjust the colour and intensity of the LIFX bulb means you may be able to promote improved rhythm regulation indoors, without the help of chemicals. The dLUX team has provided us with a rough schedule of sunlight throughout the day. On a clear day, the light outside progresses from a low, orange-tinted hue in the morning to an intense, bright white around noon, and back to a dim orange in the evening. Periods of darkness are replaced by reddish-orange light, which enables sight but has little to no effect on the production of melatonin.

Using this schedule as a guide, you can use the LIFX bulb and app together to mimic natural patterns of daylight and darkness:

When you wake up, set the bulb to an orange hue from the colors menu, with a brightness of about 65%.

In the mid-morning, switch to the whites menu to select a medium-white hue. Turn up the brightness to about 80%.

Around mid-day, ramp up to 100% brightness and a bluish-white tint.


In the mid-afternoon, turn it back down to a warm white with about 75% brightness

At dinner time, switch back to the colours menu and set the bulb to a pleasant yellow-orange hue at around 55% brightness.


When you’re getting ready for bed, ramp down to a reddish-orange hue and 30% brightness or less.


With this knowledge in hand, the LIFX bulb becomes a powerful tool in potentially promoting health and circadian rhythm regulation. Note that the suggestions in this post are only guidelines. You may need to adjust intensity and colour settings to better fit your environment and individual preferences.