Is Blue Light Destroying Your Sleep Hormones?

We weren’t built for this kind of light, it feels like I, personally, was extra not built for it.

Not the flickering glare of a midnight email or the synthetic shimmer of LED headlights.
The blue glow that pulses from your phone like it knows you’re tired, but wants you awake anyway is something I think everyone is familiar with at this point in time.

I’m sure you’ve had an inkling at this point in time and this isn’t brand-new information, but your screen might be stealing your sleep.

I’m not talking about the fact that you spiral and doom-scroll until 3am (although that’s bad too), but I mean more biologically…cell by cell.

This is the sad story of melatonin disruption, of circadian rhythms, and of a species that used to rise with the sun and now can’t remember what tired should feel like as we’re stuck in the perpetual grasp of exhaustion.

What Is Melatonin, and Why Does It Matter?

Melatonin isn’t just the “sleep hormone,” it’s your body’s quiet conductor. It’s a soft signal that says “it’s safe now.” Ahh yes, now we can slow down a little bit. Or even something like, yes, the sun is gone, you can rest now.

Your brain starts producing melatonin when your eyes stop seeing blue…blue light, to be exact, you know, the kind that signals daylight. Blue light tells your hypothalamus, we’ve got things to do, so better buck-up, Betty.

In a world where our homes glow at midnight, and phone screens flicker in our faces until we drop them onto our chests in sleep’s near-miss (or our face, and then get angry when it gives you a fat lip)…melatonin doesn’t stand a chance.

The Science of Blue Light Suppression

Blue light lives in the 460–480 nm range. It’s the wavelength of alertness and morning, so your brain associates it with productivity. It’s super great when you’re sipping coffee at 9am, but a total disaster when you’re scrolling TikTok at 11pm.

Studies published in PubMed show blue light exposure before bed suppresses melatonin by up to 85%. It also delays sleep onset and reduces REM sleep, which is the deepest, dream-filled part of the cycle. Blue light also increases wakefulness hormones like cortisol.

That’s not even the worst part though, it tricks your brain into thinking the day isn’t over, even when your body begs otherwise.

This isn’t just about fatigue either, although if you’re like me, most days are a tired haze where I only truly feel wide awake for a few hours.

Melatonin is anti-inflammatory and regulates cellular repair. Some people on the interwebs also theorize that it may even play a role in protecting against neurodegenerative diseases and cancer. When we strip it away night after night, the consequences stack like digital dominoes with insomnia, anxiety, and depression rearing their ugly heads. Hormonal imbalance, weight gain, and brain fog are also some side effects you could see from not enough melatonin.

You don’t just lose sleep either, you lose the healing that sleep was meant to bring to your body. Like déjà vu, the body remembers the pattern even when the mind forgets the why.

Screens Are the New Sunset

There was a time when the day ended because it got dark. Ah, the glory days. Now, we end the day because we tell ourselves to.

We scroll until the phone hits our face (sorry I keep coming back to this, but I’ve done it more times than I can count and I’m bitter about it clearly). I send emails under the soft blue light of my smart bulbs at literally all hours of the night. It’s not unusual for me to send an email at 2am, and while that might sound weird, just know I work until past midnight most days, so it’s not like a drunk text or anything unprofessional.
Today though, we all seem to fall asleep in beds that feel more like server farms than sanctuaries.

When we wake up groggy, or irritable, or our bodies aching we blame coffee, or age, stress, or those energy drinks we had after noon hit. The truth is though, it might just be the light…brightening when it should be dimming, and buzzing when it should be fading.

The hormone doesn’t just help you fall asleep, it tells the rest of your hormones what time it is. Delay melatonin, and you delay growth hormone (muscle repair, skin health, etc etc) and even leptin (satiety signal). Ghrelin your hunger cue hormone gets messed up as well, so your general food habits are thrown through a nice little loop-de-loop. Insulin is another one that gets thrown off, which is used in your body for glucose regulation. Sort of important things overall.

It’s just a domino effect with no snooze button, and it starts with a flick of a switch, or a scroll of the thumb.

Is Blue Light the New Sugar?

We used to fear sugar, then fat, then gluten, now it feels like it’s dairy again and garlic in my restaurant. Now, blue light is taking its turn in the spotlight, and for good reason.

Just like sugar hijacks your energy and immune system, blue light hijacks your rest. It pretends to be natural and hides in everything, and we’ve completely normalized our dependence on it.

This isn't about fear mongering, it’s about remembering what real tiredness feels like, and finally reclaiming it.

As I learned while writing Why I Switched from Fluorescent Bulbs to Incandescent Ones, not all light is created equal. Some lights mimic firelight, while others mimic the sun, and when the sun never sets, melatonin never gets made.

By 9:00 pm blue light should fade. Melatonin begins to rise naturally if you avoid all the blue lights around you. If you do that then by 10:00pm you might feel the first true yawn coming on. 11:00 pm your body temperature drops and brain clears, which makes way for sleep to arrive.

But with screens on your night might look more like this: 9:00 pm, still reading. 10:00 pm, still texting your sister-in-law about her donut recipe. 11:00 pm still glowing and doom-scrolling, then by 1:00 am when you finally try to sleep your brain says “sunlight”.

It’s not insomnia, even though it was probably diagnosed as such, no it’s just interruption.

Not All Blue Light Is Bad

The problem isn’t blue light itself, it’s timing. Morning blue light wakes you up and resets your clock and tells your body to produce serotonin, the precursor to melatonin.

The real threat here is blue light at the wrong time. Just like magnesium balances brain aging, light needs balance too. The problem is, we don’t let the night be night anymore.

Moving forward, use red or amber lights at night, they don’t suppress melatonin the way blue light does. Wear blue light–blocking glasses after sunset. Try this top-rated pair on Amazon fashionable (enough), lightweight, and scientifically backed. I use these when I’m blogging late at night. I also put this screen protector on my phone that seems to help a little bit.

Use “night shift” mode or f.lux on your devices if they have it, these reduce blue emissions when the sun sets. Turn off screens an hour before bed if you can. Read real books and journal or meditate, or hell, do nothing at all, and let your brain rediscover silence.

Get morning sunlight, even 10 minutes outdoors anchors your circadian rhythm for the next 24 hours. (Best to do 20 minutes if possible!)

Go to bed at the same time, even on weekends, sleep just adores rhythm more than it loves rebellion.

Why Can’t We Sleep Anymore?

Yeah, so it’s not just stress even though that doesn’t help at all. It’s not just your caffeine overdose (although I beg you to take it easy on that), and it’s not even just your phone.

Rest has just become optional in a society that rewards constant availability, but your body hasn’t evolved as fast as your inbox. Sleep still needs darkness and a break from the bright.

We’ve built a world where sleep feels like surrender, but in truth, sleep is strategy. As I explored in The Meditative Mind, stillness isn’t just healing, it’s foundational and you really need it.

Blue light isn’t the enemy, but our refusal to dim it might be. We were meant to live by the sky…sunlight by day, starlight by night. Really, the moon was never meant to compete with a billion LEDs.

So tonight, let it be dark and let your screens fade. Let your thoughts flicker instead, you really never know what you’ll think of when they finally come back.

When you feel that sleep pull rising through your spine and stomach, know that melatonin has arrived…not from a pill, but from your own body, doing its thing.