/
© 2026 RiffOn. All rights reserved.
  1. Huberman Lab
  2. Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery
Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab · Dec 1, 2025

Dr. Glen Jeffery explains how long-wavelength light boosts mitochondrial health, while modern LED lighting may pose a public health risk.

Red Light Therapy is Most Effective in the Morning, Before 11 AM

The benefits of red light therapy are highly time-dependent. Mitochondria are most receptive and primed for ATP production in the morning, making treatments before 11 AM significantly more effective. Afternoon sessions have little to no effect as mitochondria shift to other maintenance tasks.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Indoor Plants Act as Reflectors for Beneficial Infrared Light

All plant matter naturally reflects infrared light. Placing plants in an office or home, especially where they can catch sunlight, increases the ambient levels of health-promoting long-wavelength light. Architects are beginning to incorporate this principle into building design to create healthier indoor environments.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Greater Sunlight Exposure Correlates with Lower All-Cause Mortality

Contrary to the dominant narrative focused on skin cancer risk, emerging research shows that higher sunlight exposure is linked to longer life and reduced all-cause mortality, particularly from cardiovascular disease and cancer. The key is to get regular sun exposure while strictly avoiding sunburn.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Public Health Experts Warn Modern LED Lighting May Be a Crisis on Par with Asbestos

The unbalanced, short-wavelength-heavy spectrum of common LED lights, which lacks counteracting long-wavelength red light, may cause systemic mitochondrial dysfunction. Some scientists believe this is a major public health issue with a potential impact comparable to that of asbestos.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Red Light Boosts Mitochondrial Energy by Changing Water Viscosity, Not by Direct Absorption

Contrary to popular belief, mitochondria don't directly absorb long-wavelength light. Instead, the light is absorbed by the surrounding "nanowater," reducing its viscosity. This allows the ATP-producing protein motors within mitochondria to spin faster and more efficiently, generating more cellular energy.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Long-Wavelength Light Penetrates Clothing, Skin, and Bone to Scatter Throughout the Body

Long-wavelength light (red and infrared) is not blocked by skin or even bone. It passes through tissues and scatters internally, affecting mitochondria throughout the body. Experiments show that light shone on a person's chest can be detected coming out of their back, confirming deep-body penetration.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Early Stage Disease Intervention is Critical for Red Light Therapy Success

Red light therapy is a powerful preventative and early-stage intervention tool, but it cannot reverse advanced disease. Clinical trials showed it failed to help patients with late-stage macular degeneration or severe rheumatoid arthritis, yet significantly helped those with milder conditions, emphasizing the need for early application.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Long-Wavelength Light Passes Directly Through the Human Skull

Experiments show that long-wavelength red and infrared light can penetrate the human skull, which it passes through more easily than deoxygenated blood in veins. This property is already being used by biomedical engineers to non-invasively monitor mitochondrial function in the brains of newborns who have suffered a stroke.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Long-Term LED Lighting Causes Fatty Liver and Anxiety in Mice

Mice living under standard LED lighting develop significant health problems, including fatty livers, smaller kidneys and hearts, unbalanced blood glucose, and anxiety-like behaviors. This suggests the unbalanced light spectrum in modern indoor environments may have profound, detrimental systemic effects on mammalian health.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Vision Improvement from Red Light Therapy Acts Like a 5-Day Switch

The visual benefits of red light therapy are not cumulative or gradual but act like a binary switch. A single session produces a measurable improvement in vision that lasts for approximately five days before abruptly switching off. This finding informs the optimal frequency for light therapy protocols targeting eye health.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Shining Red Light on a Small Skin Area Systemically Lowers Blood Glucose Spikes

Red light therapy has systemic, not just local, effects. In one study, illuminating a small patch on participants' backs with red light before a glucose challenge reduced their peak blood sugar spike by over 20%. This suggests mitochondria communicate body-wide to create a systemic metabolic response.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago

Replace LED Bulbs with Dimmable Halogen or Incandescent Lights for Health Benefits

Incandescent and halogen bulbs provide a full, sun-like spectrum of light that supports mitochondrial health, unlike spectrum-limited LEDs. Using a dimmable halogen lamp, even at low brightness, provides ample beneficial infrared energy. This simple, low-cost switch can counteract the negative effects of modern indoor lighting.

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery thumbnail

Using Red Light to Improve Metabolism & the Harmful Effects of LEDs | Dr. Glen Jeffery

Huberman Lab·3 months ago