Night Screens: The Silent Enemy of Your Melatonin

Published on May 03, 2026 | Translated from Spanish

The World Health Organization has once again focused on a habit that many consider harmless: checking your phone before sleeping. Exposure to blue light from screens at night reduces the production of melatonin, the hormone that regulates sleep. This imbalance not only causes insomnia but is also linked to concentration problems, chronic fatigue, and an increased risk of metabolic disorders. The problem is global and affects all ages.

A hand holds a bright phone in the dark, its blue light hitting a sleepy face; in the background, the moon and a clock mark the night.

How blue light interferes with the circadian cycle 🌙

Artificial light from devices emits a wavelength close to 480 nanometers, which tricks the pineal gland. It interprets that it is still daytime and suppresses melatonin synthesis. Technically, current OLED and AMOLED panels, although offering better contrast, still emit high peaks of blue light. Software filters reduce color temperature but do not completely eliminate the light stimulus. The most effective solution remains turning off devices at least one hour before going to bed.

The phone also knows you should sleep, but it doesn't care 📱

Wellness apps remind you it's time to put the phone down, but right after they suggest you activate night mode to keep watching videos. It's like a liquor store clerk recommending you not to drink while serving you a glass. The irony is that we use technology to measure our sleep, while the same technology steals it from us. In the end, the only one that sleeps well is the charger.