Why using phones at night reduces melatonin

What is melatonin?

Melatonin is a sleep hormone produced by the brain (pineal gland).
It tells your body: “It’s time to sleep.”

What happens when you use a phone at night?

1. Mobile screens emit blue light.

This light:

• Tricks your brain into thinking it is daytime

• Suppresses (reduces) melatonin production

2. Delays your body clock

Your body has a natural cycle called the
circadian rhythm. #

Night-time phone use:

• Shifts this rhythm later

• Makes you feel less sleepy at night

3. The brain stays active

• Scrolling, videos, messages → mental stimulation

• Your brain stays alert instead of relaxing

Result:

• Late sleep onset

• Poor sleep quality

• Daytime tiredness

Simple Example

Without phone:
Melatonin rises → you feel sleepy

With phone:
Blue light blocks melatonin → you stay awake

What you can do

• Stop phone use 30–60 minutes before bed

• Use night mode / blue light filter #

• Keep the phone away from the bed

• Prefer dim lighting at night

Message:

“Mobile light tells your brain it’s still daytime, so sleep hormone doesn’t work properly.”

Key:

1. Circadian rhythms are the 24-hour, internal biological processes that regulate the sleep-wake cycle, hormone release, digestion, and body temperature. #

2. A blue light filter reduces the amount of high-energy blue light emitted by digital screens. By shifting the display toward warmer, yellowish tones, these filters help minimize digital eye strain and prevent the suppression of melatonin. #