How the Pineal Gland Affects Your Circadian Rhythm and Sleep

Various New Age religious sects connect it with the mystical third eye.

French philosopher René Descartes believed it to house the body’s soul.

And in modern science, it’s been located as the brain’s sole producer of melatonin, a hormone vital to the normal function of the sleep/wake cycle.

It’s the pineal gland – and with the help of modern research, science is at last beginning to unlock the secrets of this mysterious organ.

Image: palms cup glowing brainWhat Is the Pineal Gland?

In more concrete terms, the pineal gland is a tiny, pinecone-shaped nodule pretty much smack dab in the middle of your brain.

It’s found in all animals with backbones, and in humans, it’s only about 1 cm in length.

Its main purpose in our species is regulate a portion of our circadian rhythm, and the way it does this is by producing the hormone melatonin as it starts getting towards bedtime.

The pineal gland is particularly susceptible to calcification with age – more so, in fact, than any other organ in the human body.

Pineal gland calcification has been linked to certain neurodegenerative diseases, most notably Alzheimer’s disease.

Additionally, particularly small pineal glands have been linked to insomnia, and problems in melatonin production may be a contributing factor to this sleep disorder.

Much still remains to be known about the pineal gland and its effects on human health, but one thing for certain is that it plays a major role in the sleep/wake portion of your circadian rhythm.

What Is a Circadian Rhythm?

What does that mean, exactly?

Well, the term “circadian” comes to us from the Latin “circa,” meaning “roughly,” and “diem,” meaning day.

So, a circadian rhythm can be defined as any bodily rhythm you go through roughly once per day.

Another nodule of your brain somewhat near the pineal gland is responsible for the synchronized regulation of these cycles: a tiny cluster of about 20,000 neurons known as the suprachiasmatic nucleus.

Also known as your brain’s “master clock,” this organ plays a role in the rhythms of just about every part of your body.

From your stomach to your skin, pretty much every part of your body is in some way impacted by this master clock.

And they all feed into each other, too – which is partly why your body is at its happiest when you’ve established a regular routine.

Your master clock likes knowing what’s going to happen next, because that allows it to get the right organs ready for the right kind of work.

And if you’ve ever experienced jetlag, you know how important that kind of anticipation is for a properly functioning sleep/wake cycle.

Image: girl reaches for alarm clockHow Your Sleep/Wake Cycle Works

As with pretty much all of your bodily rhythms, your sleep/wake cycle involves a complex interplay between a whole bunch of different hormones.

If you’ve ever been going through a difficult time in your life and been unable to sleep at night, that’s probably partly because of the presence of the stress hormone cortisol in your bloodstream as you’re trying to get to sleep.

Other hormones, such as serotonin and orexin, also play a role in the sleep/wake cycle.

There’s one hormone, however, that stands out above all others.

Coming to us courtesy of that trusty pineal gland, it’s melatonin.

How Melatonin Impacts Sleep

Melatonin is more closely tied to the time of day than just about any other hormone in your body.

Sometimes called the “hormone of darkness,” it’s usually released in response to a decrease in light levels in your environment.

Because of this, the biggest jump in melatonin production typically begins shortly after sundown, although it doesn’t get up to its highest levels until the middle of the night.

Your eyes’ corneas are the ones that keep track of all those light levels, relaying a constant stream of sensory input to your optic chiasm.

This is right next to that trusty old master clock we’ve been talking about – which is, in turn, in cahoots with the pineal gland.

You see how it all fits together!

Why All of This Means for You

Now, while all this science is certainly interesting, that’s not the only reason it’s worth understanding.

The workings of your pineal gland have an awful lot of impact on your sleep/wake cycle – so if you haven’t been sleeping well lately, there’s a good chance your hormones are to blame!

There are two main ways to get your pineal gland back to where you need it to be.

Your Body Craves Routine

First of all, there’s the matter of building a regular routine.

Although we all lead busy, often unpredictable lives, there are few things your hormonal cycles like better than to know what’s going to happen next.

Your master clock wants to figure out when you’re likely to be heading off to bed, because that means it can know when it has to work its magic on all those sleep hormones we were talking about a minute ago.

Because of this, one of the absolute best ways to improve your typical sleep quality is by going to bed at the same time every single night – including the weekends!

Although we all definitely feel the urge to kick back and stay up a couple extra hours when Friday night rolls around, the more stable you can keep your sleep schedule, the better your sleep will be.

Image: woman looking at phone at nightWhy Artificial Lights Ruin Sleep

Second of all, it might be time to rethink the way you deal with artificial light.

The pineal gland, as I’ve been saying, is a highly light-sensitive organ.

In civilizations without electric lighting, most people go to sleep shortly after sunset, and wake up with the sunrise.

This is the kind of schedule your body is designed to deal with, and if you want to get the highest-quality sleep, it pays to simulate this as much as possible in your own home.

To get your melatonin levels up to where they need to be before you go to sleep, you’ll want to avoid bright lights as much as possible for about 2 hours before bed.

If you have lights with dimmer switches, this isn’t actually as difficult as it sounds – just go around and set some mood lighting as it reaches a certain point in the night, and you’ll see just how much more easily you sleep once you’re in bed!

How Electronics Affect Sleep

Unfortunately, however, that mood lighting probably isn’t all it’s going to take to get your pineal gland working quite the way you want it to.

That’s because of the way blue light – the short-wavelength rays emitted by most electronics’ LED screens – is pretty much poison to your melatonin production.

Although researchers are still trying to figure out exactly why this is, the fact is that nighttime electronics usage can majorly set back your sleep/wake cycle at a critical time in the night.

Because of this, most experts recommend cutting out all electronics at least half an hour before bedtime, or ideally around 2 hours before.

That means no phones, no TV, no tablets, no laptop – and above all, none of that in bed!

If, for whatever reason, you absolutely must look at your devices during this stretch, it’s recommended that you get some kind of light-filtering app such as f.lux or Nocturne.

Software like this is designed to block out all blue-range light from your electronics, replacing it with red-range light that’s been found to have more manageable effects on your dear old pineal gland.

The Benefits of Light-Exposure Therapy

If you’ve cut out as much artificial lighting as possible and are still finding yourself tossing and turning at night, however, an alternative method to up melatonin production is to simply increase exposure to bright light throughout the day.

Most of us spend our working days burrowed into buildings far away from the bright rays of the sun, which makes it hard for our bodies to tell the difference between afternoon and night.

The more time you can spend outside during the day soaking up that sun, the greater a contrast there will be when evening rolls around.

This has pretty much the same effect as reducing electronics usage at night – it’s just coming at the problem from the opposite end!

Many experts recommend going for a morning run before heading off to work – or even just getting outside during your lunchbreak.

If these options for some reason aren’t available to you, however – if you work a night shift, for instance – there are also some manmade options available.

Light therapy boxes, for instance, are designed to simulate the effects of sunlight.

Some clinical trials have found positive results when they’ve been tried out on insomniacs, and they’ve also found some success in combatting Seasonal Affective Disorder.


The pineal gland is quite possibly the single most important organ when it comes to your sleep, and it pays to take care of it as well as you can.

Remember, your body depends on you just as much as you depend on it!

Keep taking care of yourself – and always stay curious.