How does light therapy work?

Light can influence mood via two complementary pathways:

• Circadian & non-visual signaling: Short-wavelength (blue) light (~460–480 nm) strongly affects circadian timing and alertness via melanopsin/ipRGC pathways and related brain circuits (Vandewalle et al., 2013; LeGates et al., 2014).

• Photobiomodulation (PBM): Red/near-infrared (≈630–850 nm) light can be absorbed by cellular chromophores (e.g., cytochrome-c-oxidase), modulating mitochondrial activity and redox signaling; early clinical studies suggest potential antidepressant effects for transcranial PBM, but evidence is still emerging (de Freitas & Hamblin, 2016; Schiffer et al., 2009; Cassano et al., 2018).

In practice: blue-enriched light in the morning can anchor circadian timing and alertness, while dim, warm/red light in the evening helps maintain a calm, melatonin-friendly environment (Vandewalle et al., 2013; LeGates et al., 2014).

Applications for mood support

Regular, well-timed light exposure can help stabilize mood, energy, and focus by supporting circadian and neurobehavioral pathways.

Common applications include:

• Morning energy and motivation: Bright or blue-enriched light soon after waking supports alertness and daytime performance (Vandewalle et al., 2013; Blume et al., 2019).

• Evening wind-down: Use dim, short-wavelength-reduced lighting in the last hours before bed to support a calmer, melatonin-friendly environment (LeGates et al., 2014).

• Seasonal support: In winter months, structured bright-light exposure has demonstrated efficacy for seasonal affective disorder (SAD) and can help stabilize daily rhythm and mood (Golden et al., 2005; Lam et al., 2006; Nussbaumer-Streit et al., 2019).

Key benefits at a glance

When timed and dosed appropriately, light can support:

• Circadian alignment and non-visual alertness pathways (Vandewalle et al., 2013; Blume et al., 2019)

• Improved seasonal mood symptoms with bright-light protocols (Golden et al., 2005; Lam et al., 2006)

• Mechanistic cellular support via PBM (emerging clinical evidence) (de Freitas & Hamblin, 2016; Cassano et al., 2018)

Note: Effects depend on spectrum, intensity, timing, and individual sensitivity.

Who can benefit?

Individuals seeking to support mood stability, energy, and emotional wellbeing, especially those with low daytime light exposure, irregular schedules, or winter-season mood changes. This page provides general information only.

How to use it in practice

Morning routine: ~20–30 minutes of bright/blue-enriched light within the first hour after waking to support alertness and daytime rhythm (Blume et al., 2019).

Evening relaxation: Dim, warm/red-shifted light 1–3 hours before bedtime to reduce circadian activation (LeGates et al., 2014).

Seasonal routines: For winter mood support, consider structured bright-light sessions on most days, aligned with evidence-based SAD protocols (see references).

Consistency matters—regular patterns help the body adapt naturally.

Scientific context

Light modulates circadian, neuroendocrine and neurobehavioral systems implicated in mood. Human imaging shows wavelength- and time-of-day-dependent effects on brain regions underlying alertness and cognition (Vandewalle et al., 2013). Reviews integrate how timed light influences sleep, mood and affect (LeGates et al., 2014; Blume et al., 2019), while meta-analyses and RCTs support bright-light therapy for SAD and suggest benefits for some non-seasonal depressions (Golden et al., 2005; Lam et al., 2006).

PBM with red/NIR light is being investigated for mood disorders; early trials show promise but remain preliminary and require replication (Cassano et al., 2018; Schiffer et al., 2009).

Why redtreat

We focus on research-informed wavelengths and comfortable use—offering bright/blue-enriched options for mornings and warm/red options for evenings—to help users structure light exposure patterns that align with daily rhythms.

• Thoughtful spectra: morning blue-enriched; evening warm/red

• Even, comfortable irradiance for routine sessions

• Swiss expertise for reliability and precision

Disclaimer

References are provided for educational and informational purposes only. They summarize general research on light exposure and mood and do not constitute therapeutic or clinical claims for redtreat products. Products are not intended to diagnose, treat, cure, or prevent any disease. Individuals with ongoing mood symptoms or medical conditions should consult a healthcare professional.

Scientific references

• LeGates, T. A., Fernandez, D. C., & Hattar, S. (2014). Light as a central modulator of circadian rhythms, sleep and affect. Nature Reviews Neuroscience.
• Vandewalle, G., et al. (2013). Blue light stimulates cognitive brain activity in visually blind individuals. Current Biology.
• Blume, C., Garbazza, C., & Spitschan, M. (2019). Effects of light on human circadian rhythms, sleep and mood. Somnologie.
• Golden, R. N., et al. (2005). The efficacy of light therapy in the treatment of mood disorders: A meta-analysis. American Journal of Psychiatry.
• Lam, R. W., et al. (2006). The Can-SAD randomized controlled trial: Light therapy vs. fluoxetine for winter SAD. American Journal of Psychiatry.
• Nussbaumer-Streit, B., et al. (2019). Light therapy for preventing seasonal affective disorder (Cochrane Review). Cochrane Database of Systematic Reviews.
• de Freitas, L. F., & Hamblin, M. R. (2016). Proposed mechanisms of photobiomodulation. IEEE Journal of Selected Topics in Quantum Electronics.
• Schiffer, F., et al. (2009). Psychological benefits after near-infrared light to the forehead: pilot in MDD/anxiety. Behavioral and Brain Functions.
• Cassano, P., et al. (2018). Transcranial photobiomodulation for major depressive disorder: proof-of-concept RCT. Lasers in Surgery and Medicine.