Junk Light 101: Why Your LED Bulbs Are Disrupting Your Hormones

Last updated: January 2026

TL;DR: Modern LED bulbs emit unbalanced light: heavy in blue wavelengths (460 to 480 nanometers (nm), the unit used to measure light color), missing the near-infrared found in sunlight. This "junk light" suppresses melatonin by up to 71%, increases insulin resistance within 30 minutes of exposure, and strains your nervous system through invisible flicker. This guide explains the science and the fix.

In this guide, we answer:

• Is "junk light" a real problem or wellness hype?
• Why does the blue spike in LED bulbs affect your metabolism, not just your sleep?
• What is LED flicker and why does it cause headaches even when you can't see it?
• What is the 2-step protocol to fix your home's light environment tonight?

You've optimized your water. You buy organic. You track your sleep with a ring or a watch. You take magnesium before bed and avoid screens after 9pm.

And yet you still feel wired at night. Your sleep scores plateau. Your fasting glucose creeps up for reasons you can't explain.

The problem isn't your diet. It's the "energy efficient" bulbs you were told to buy.

The light filling your home after sunset is engineered for electricity savings, not human biology. And the gap between what your eyes perceive as "normal white light" and what your body experiences at a cellular level is where health quietly erodes.

What Is Junk Light?

Junk light is artificial illumination that lacks the balanced spectrum of natural sunlight. Think of it like processed food for your eyes.

Sunlight contains a full spectrum of wavelengths: blue for alertness, red and near-infrared for cellular repair. Your biology evolved under this balance. When the sun rose, blue wavelengths signaled wakefulness. When the sun set, they disappeared, and warmer tones dominated firelight.

Modern LEDs flip this equation. They concentrate blue wavelengths (peaking at 450 to 480nm) while stripping out the red and near-infrared wavelengths your mitochondria use for energy production. NASA-funded research has demonstrated that red and near-infrared light increases cellular ATP production by 70 to 90%, supporting tissue repair and recovery.

LEDs give you the alertness signal without the recovery signal. It's an incomplete message that your body can't properly interpret.

Why Does the "Blue Spike" Matter?

Most people assume white light is just light. It isn't. When you look at the wavelengths a standard LED bulb actually produces, you see a sharp spike in the blue range (450 to 480nm). This is the exact wavelength band that specialized light-sensing cells in your eyes are most sensitive to.

These cells, called melanopsin receptors, don't help you see. They tell your brain what time it is.

When blue light hits melanopsin receptors after sunset, your body receives a powerful "it's daytime" signal. The downstream effects extend far beyond sleep.

Research from Northwestern University found that a single night of sleeping in moderate room light (100 lux, roughly a dim bedroom with the blinds up) increased insulin resistance by around 15%. A separate study from the same team showed that blue-enriched light increased insulin resistance by 30% within just 30 minutes of exposure. Participants also showed higher blood sugar spikes after meals.

This isn't about feeling a little tired. It's metabolic disruption at the hormonal level.

A 2016 report from the American Medical Association on LED streetlights noted that white LEDs are at least five times more powerful at suppressing melatonin than the older streetlights they replaced. And research published in the Journal of Clinical Endocrinology & Metabolism found that ordinary room light suppressed melatonin by 71.4% compared to dim conditions.

Your kitchen lights, your bathroom vanity, your hallway fixtures: they're all broadcasting a biological wake-up call long after you want to be winding down.

The Invisible Strobe: Flicker and Your Nervous System

Here's a problem that blue-light glasses can't solve.

LEDs powered by standard AC electricity don't produce constant light. They cycle on and off with the alternating current: 100 times per second in countries with 50Hz power, 120 times per second in 60Hz countries like the United States. This is called flicker.

You can't consciously see it. But your nervous system detects it.

A double-blind study in UK offices compared workers under standard flickering lights versus flicker-free alternatives. The workers didn't know which type they were under. The result: headaches and eye strain were more than halved under flicker-free lighting. Around 8% of workers reported frequent headaches under standard lighting. Under flicker-free conditions, that number dropped to zero.

Industry safety guidelines have established thresholds for how much flicker is too much. Most cheap LED bulbs exceed them.

A 2020 review by an international panel of radiation safety experts put it bluntly: flicker represents "the only clear, acute adverse health effect from LEDs."

This is an engineering problem. Supplements won't fix it. Blue-light glasses won't fix it. The solution is eliminating the flicker at the source, which means using lights powered by DC battery rather than AC wall current.

Standard Night Light vs. Circadian-Safe Lighting

Here's what separates a standard night light from one designed for sleep:

The Light Detox Protocol: 2 Steps

Fixing your light environment doesn't require rewiring your house. It requires understanding two distinct problems and solving each one.

Step 1: Block External Light (The Shield)

True sleep optimization starts with true darkness. Research shows that even 5 to 10 lux can suppress melatonin in light-sensitive individuals. That's approximately the amount of light from a streetlamp bleeding through a curtain gap.

Standard blackout curtains fail because they don't seal. They hang from a rod, leaving gaps at the top, sides, and bottom where light pours through. This "halo effect" can raise your sleeping environment to 10 to 50 lux, well above the threshold for hormonal disruption.

The fix is a sealed blackout system. Side channels that lock against the wall. A top seal that blocks light from above. A bottom seal to the windowsill. No gaps means no light means no suppression.

If you want to understand the science of light thresholds and sleep in more depth, our sleepmaxxing guide breaks down the research.

Step 2: Use Circadian-Safe Navigation Lighting (The Safe Passage)

Darkness is the goal for sleep. But you still need to see at night. Bathroom trips. Checking on kids. Getting water. The problem is that flipping a standard light switch undoes everything.

The solution is red light at 620nm or above. Research confirms that wavelengths in this range do not suppress melatonin because they fall outside the sensitivity range of melanopsin receptors. You can see where you're going without telling your brain it's morning.

The UBlockout Motion Sensor Night Light is designed specifically for this purpose. It emits pure red light at 620 to 625nm with zero flicker (battery powered, not AC). The motion sensor activates only when you move, so there's no constant glow. Use it in bathrooms, hallways, nurseries, or anywhere you need to navigate at night without disrupting your circadian rhythm.

For shift workers who sleep during the day, this combination is especially critical. UBlockout shades block daylight completely. Red navigation lighting preserves melatonin when you need to move around your darkened space.

Your Light, Your Choice

Your biology evolved under fire and sunlight. Both produce continuous, full-spectrum light with minimal blue content after dark. Modern LEDs produce neither.

The research is clear. The solution is straightforward. Block the light that disrupts. Use the light that doesn't.

Shop the UBlockout Blackout Shades | Shop the Motion Sensor Night Light

Frequently Asked Questions

What is junk light? Junk light is artificial illumination that lacks the balanced spectrum of natural sunlight. Modern LEDs concentrate blue wavelengths while missing the red and near-infrared wavelengths that support cellular recovery.

Do LED bulbs affect hormones? Yes. Research from Northwestern University found that LED light exposure increased insulin resistance by 15 to 30% and suppressed melatonin by up to 71%.

What is the best light color for sleep? Red light at 620nm and above. Wavelengths in this range don't activate the receptors that signal wakefulness to your brain.

What is LED flicker? LED flicker occurs when lights cycle on and off with wall power, typically 100 to 120 times per second. You can't see it, but research shows it more than doubles the incidence of headaches and eye strain.

How do I reduce junk light exposure? Two steps: block external light with a sealed blackout system for sleep, and use red-light navigation lighting for nighttime movement instead of standard white lights.

Are incandescent bulbs healthier than LEDs? They produce a more balanced spectrum with less blue light and no flicker. However, for nighttime navigation, purpose-built red lights are the better option.