The Effects of Light Therapy on Sleep Problems

Med Glow LED Science Column

Do you experience any of the following?

Lying in bed for more than 30 minutes without being able to fall asleep

Waking up frequently during the night

Feeling tired even after sleeping for 8 hours

Decreased concentration and memory problems during the day

Long-term reliance on sleeping pills to fall asleep

If these symptoms persist for more than a few weeks, you may be facing more than just “poor sleep”—you may have a sleep disorder

According to research statistics, sleep disorders have become one of the most common health issues in modern society and are closely linked to obesity, diabetes, cardiovascular disease, anxiety, depression, and cognitive decline.

Why is sleep so important?

Sleep is not merely rest.

When we enter deep sleep, the brain performs many important functions:

✓ Repairing nerve cells
✓ Clearing metabolic waste
✓ Consolidating memory and learning abilities
✓ Regulating hormone secretion
✓ Maintaining normal immune system function

Research has found that during sleep, the brain activates a mechanism similar to a “cleaning system” to flush out metabolic waste accumulated during the day. When sleep quality declines, these clearance mechanisms are also affected.

Common Causes of Sleep Disorders

Modern lifestyles are constantly disrupting the body’s circadian rhythm.

1. Excessive Exposure to Blue Light
Blue light emitted by smartphones, tablets, and computers can affect melatonin secretion.
Melatonin is a key hormone that regulates sleep.

2 . Stress and Anxiety
When stress hormones remain elevated for long periods, the brain stays in an alert state, making it harder to fall asleep.

3 . Circadian Rhythm Disruption
Staying up late, shift work, and traveling across time zones can all disrupt the body’s circadian rhythm, leading to poor sleep quality.

4. Aging
As we age, the body’s natural production of melatonin gradually decreases, making middle-aged and older adults more prone to insomnia.

The Relationship Between Red Light Therapy and Sleep
In recent years, scientists have begun studying the effects of red light and near-infrared light therapy (Photobiomodulation, PBM) on sleep.

Red light therapy is not a sleeping pill.

It does not force you to fall asleep, but rather helps the body return to a more natural sleep state by improving cellular energy metabolism and supporting normal physiological rhythms.


How does red light affect sleep?

Boosting Mitochondrial Energy Production

Red light and near-infrared light are absorbed by the mitochondria in cells.

Mitochondria are the body’s powerhouses, responsible for producing ATP (cellular energy).
When energy metabolism is enhanced, the nervous system and brain function can maintain a healthier state of operation.

Supports Melatonin Balance

A 2012 study found that participants who received whole-body red light exposure for 14 consecutive days showed significant improvements in both sleep quality and serum melatonin levels.

Melatonin is often referred to as the "sleep hormone."

When melatonin secretion is normal:
✓ Easier to fall asleep
✓ Deeper sleep
✓ Fewer nighttime awakenings

Helps the brain repair itself at night

Recent research has put forward an important perspective:

Sleep is not just rest; it is a crucial time for the brain to cleanse itself.
Research suggests that light-based bio-regulation technology may support the brain’s metabolic processes and cerebrospinal fluid circulation, thereby aiding the brain’s nighttime repair process.

What Have Scientific Studies Found?

Improved Sleep Quality

Several studies suggest that red light and near-infrared light therapy may improve subjective sleep quality and sleep satisfaction.

Reduced Insomnia Symptoms

A 2024 systematic review indicated that light therapy shows potential for improving sleep quality in people with insomnia, but further large-scale studies are needed to confirm these findings.

Improved Daytime Alertness and Mood

Some studies have found that after receiving near-infrared light therapy, participants experienced improved relaxation, mood, and daytime alertness.

A New Direction for Chronic Insomnia
A 2025 randomized controlled trial showed that transcranial photobiomodulation (tPBM) helps improve sleep quality and daytime sleepiness in patients with chronic insomnia.

Who should take note?
✔ People with chronic insomnia ✔ People with light sleep or vivid dreams ✔ People who wake up frequently during the night ✔ High-stress office workers ✔ People who frequently stay up late ✔ Shift workers ✔ People who want to improve their sleep quality and recovery