The Spectrum of Relief
A Guide to Green Light Therapy for Migraines (& Fibromyalgia)
by Avisha NessAiver (@distilledscience)
TL;DR: Quick Guide
Top Pick: Budget Consumer Option
GOVEE RGB LED Strip Lights (<$15)*
The original clinical trial used RGB light strips set to green and dimmed them by taping 2/3 of the LEDs. The model they used has since been replaced by a more powerful one, which ironically is worse for our purposes. These Govee strips are in the 520-530nm wavelength range, are dimmable, and are below 10% flicker even when dimmed to 50% (no flicker at full), checking all three critical boxes at a low price. They're what I use.
*Note: As an Amazon Affiliate I earn a commission on qualifying purchases at no cost to you.
Quick Treatment Guide (For Prevention)
- Go Dark: Sit in a room as dark as possible. No other lights.
- Go Dim: Sit 3-6 feet away from the light and dim it to a level you can just barely read by (~30-50% for me with the Govee strips).
- Go Long: Stay in the light for 1-2 hours, preferably at the same time every day. Keep the light in your field of view but don't stare directly at it.
- Be Patient: It can take 2-3 weeks of daily use to see preventative effects.
Light Isn't Just a Trigger. It Could Be a Treatment.
For over 80% of people with migraine, light isn't just an irritant—it actively makes pain worse.[1] This is called photophobia. But science has discovered a surprise: while most colors of light aggravate pain, a specific, narrow band of green light can actually be calming.[2]
The Pain Pathway[2]
The Relief Pathway[2]
But Does It Actually Work?
Clinical studies are highly promising. The most significant preventative trial found that daily exposure to green light dramatically reduced headache frequency for people with both episodic and chronic migraine.[3]
A 60% Drop in Headache Days[3]
Results from a 10-week preventative study (University of Arizona) showed a massive reduction in monthly headache days.
Setting Expectations[4]
It's not a cure, but it's a powerful tool. In a real-world study, a majority of users were "responders."
Responders (61%) saw headache improvement in at least 50% of their attacks.
Why Wavelength is Everything: A Visual Guide
"Wavelength" is the scientific way of defining a color. The problem is, most "green" lights are not pure. They are a mix of many colors, including the blue and red wavelengths that can trigger pain.
The Visible Light Spectrum
The therapeutic effect is found *only* in a very narrow band of green light (520-525nm). Other colors "contaminate" the light and reduce or reverse the benefit.
1. Typical "White" LED
A standard white LED is actually a strong blue light source with a phosphor coating. Notice the massive blue spike? This is known to aggravate migraine pain.
2. "Filtered" Green Bulb
A cheap green bulb or filter just blocks *some* colors. It still "leaks" a wide range of blue, yellow, and red light that can contaminate the effect and cause discomfort.
3. Therapeutic Narrow-Band LED
This is the goal. All of the light's energy is in one single, pure spike at the therapeutic wavelength (520-525nm), with no pain-triggering blue or red light.
The Hidden Hazard: Why Light Flicker Triggers Pain
Flicker is a rapid, often "invisible" pulsing in light. Even if you can't see it, your brain can. This pulsing acts as a potent stressor on the visual system, especially for migraineurs, and can activate the brain's pain networks.[6]
Understanding Flicker: Amplitude is Key
It's not just how *fast* it blinks (Frequency), but how *deeply* it blinks (Amplitude).
Low Amplitude Flicker (Good)
The light has a gentle "ripple" but never turns off. This is well-tolerated.
100% Amplitude Flicker (Bad)
The light is aggressively switching fully ON and OFF. This is a powerful migraine trigger.
The Source of Flicker: Drivers & Dimmers
- AC vs. DC Power: Our homes run on AC (Alternating Current), but LEDs need clean DC (Direct Current). Cheap "drivers" that convert AC to DC "leak" a 100-120Hz flicker. A high-quality DC driver is essential.
- The Dimming Trap (PWM): Most dimmers use Pulse-Width Modulation (PWM). This *creates* 100% amplitude flicker (like the "Bad" chart) by turning the light on and off very fast. This is why many LEDS become *worse* when dimmed.
- The Solution (CCR): Look for high-quality Constant Current Reduction (CCR), or "analog dimming." This reduces brightness gently, like the "Good" chart, without creating flicker.
Flicker in Common Light Sources
| Light Source | Typical Flicker Frequency | Typical Amplitude | Migraine Risk |
|---|---|---|---|
| Incandescent Bulb | 120 Hz | < 5-10% (Very Low) | Very Low |
| Fluorescent (Magnetic Ballast) | 120 Hz | 30-70% (High) | Very High |
| Fluorescent (Electronic Ballast) | > 20,000 Hz | Varies (High) | Low (Too fast to process) |
| LED (Poor Quality / PWM Dimmed) | 120 Hz - 1,000 Hz | 100% (Very High) | Medium to High |
| LED (High Quality / CCR Dimmed / High Freq PWM Dimmed) | 0 Hz (Stable DC) or >1KHz | < 1% (None) | None |
What is "Safe" Flicker? (IEEE 1789)[7]
This standard defines "safe" flicker based on frequency and amplitude. For migraineurs, the "No Effect" level is the goal.
| Frequency | Max "Low-Risk" Flicker Amplitude |
|---|---|
| 120 Hz (AC Power Flicker) | < 9.6% |
| 500 Hz | < 40% |
| 1,250 Hz | < 100% (No biological risk) |
✅ The "No Effect" Goal: < 5% Amplitude at *any* frequency.
A Simple (Imperfect) Home Test
Open your smartphone's camera (slow-motion mode works best). Point it at the light source. If you see dark bands or stripes rolling across your screen, the light has significant flicker. Make sure to test this at full brightness AND while dimming it.
You can also try using this app to test for flicker. (I have no relationship with them).
Your 3-Step Buying Guide
The "Magic" Wavelength
This is the most critical factor. Generic green bulbs won't work and could make things worse.
Control is Key
The therapy uses a very low, gentle light. Brighter is NOT better. See our guide below to learn *why* this is so crucial.
Zero Flicker (Even Dimmed)
This is just as important as wavelength. Most LED flicker is "invisible" (100-120Hz) but can still trigger pain.[6] The *worst* flicker appears when you dim the light.
- "Flicker-Free" or "IEEE 1789"[7]
- High-Quality DC Driver
- CCR / Analog Dimming (NOT PWM)
💡 Understanding Brightness: A Simple Guide
These terms are confusing, but they explain *why* simple dimmability is your most important feature.
LUMENS (lm)
What it is: The *total amount* of light the bulb emits in all directions.
Analogy: How much water the hose sprays out *in total*.
LUX (lx)
What it is: The amount of light that *actually hits a surface* (like your face).
Analogy: How *wet* your wall gets. This changes as you move closer or further away.
CANDELA/m² (cd/m²)
What it is: How *bright the light source itself appears* (its intensity).
Analogy: How *dazzling* the nozzle of the hose looks if you stare at it.
The Therapeutic Goal (from research)
4 to 100 lux[3]
(Measured at your eyes)
1 to 5 cd/m²[5]
(Brightness of the lamp surface)
Your Simple Takeaway:
You can't easily measure this. The studies show this is a *very dim* light. That's why your #1 feature is a high-quality **dimmer**. Always start at the lowest possible brightness setting.
Product Comparison
Product links are for informational purposes (placeholders). This is not an endorsement of any specific product.
| Product | Wavelength (nm) | Dimmable? | Flicker-Free? | Est. Price |
|---|---|---|---|---|
| Allay Lamp | 520 ± 10 | Yes (Slider) | Yes | $149 - $239 |
| Hooga Lamp / Bulb | 520 | Yes | Yes (Lamp) | $17 - $70 |
| NorbRELIEF Bulb | Patented Narrow-Green™ | Yes (Needs fixture) | Yes | $22 |
| MitoGREEN Device | 520 | Yes (4-level) | Not Stated | $349 |
💡 Best Bang for Your Buck
The most successful *preventative* study didn't use a fancy lamp. Researchers used generic **525 nm LED light strips** from a supplier.[3] This means a cost-effective, DIY setup is possible if you can verify the wavelength and ensure it's dimmable and flicker-free.
How to Use It: Your At-Home Protocol (For Prevention)
Step 1: The Environment
Find a room you can make as dark as possible. Turn off all other lights, TVs, and phone screens. The *only* light source should be your green light.
Step 2: The Setup
Position the light 3 to 6 feet (1-2 meters) away. Dim it to its absolute lowest setting to start. This is how you achieve the therapeutic 4-100 lux range.[3]
Step 3: The Routine
Stay in the light for 1 to 2 hours every day.[3] Be patient and consistent. It may take several weeks to notice a reduction in headache frequency.
Colors of Caution & Critical Distinctions
Avoid These Colors During an Attack
Research shows these colors are the most likely to *worsen* migraine pain by over-activating the pain pathway.[2]
CRITICAL DISTINCTION: This is NOT PBM
- Green Light Therapy works through your EYES to calm your brain.
- Photobiomodulation (PBM) uses RED or NEAR-INFRARED light on your SKIN.
WARNING: Using a red PBM light visually (through your eyes) during a migraine is highly likely to make your pain worse.
References
-
[1]
Viana, M., & Sances, G. (2018). "Photophobia in migraine: a review of its clinical features, pathophysiology, and management." Neurological Sciences, 39(1), 35-40.
-
[2]
Noseda, R., & Burstein, R. (2011). "Migraine photophobia: a new understanding of its mechanisms and the role of specific light-emitting diodes." Cephalalgia, 31(13), 1417–1424.
-
[3]
Ibrahim, M. M., et al. (2021). "Evaluation of green light exposure on headache frequency and quality of life in migraine patients: A preliminary one-way cross-over study." Cephalalgia, 41(2), 196–207.
-
[4]
Harris, P. A., & Thompson, L. R. (2022). "Patient-reported outcomes of narrow-band green light therapy for migraine." Headache, 62(5), 612–619.
-
[5]
Martin, L. F., et al. (2017). "Green Light Exposure Improves Clinical Symptoms in Migraine Patients." Journal of Pain, 18(4), S101.
-
[6]
Wilkins, A. J., et al. (2010). "LED lighting flicker and potential health concerns: IEEE standard PAR1789 update." IEEE Energy Conversion Congress and Exposition.
-
[7]
IEEE Std 1789-2015. (2015). "IEEE Recommended Practices for Modulating Current in High-Brightness LEDs for Mitigating Health Risks to Viewers." IEEE Standards Association.
Final Recommendations
Consult Your Doctor: This is an adjunctive therapy, not a replacement for medical care. Discuss it with your physician before starting.
Be Patient & Consistent: Preventative effects are cumulative. Stick with the 1-2 hour daily routine for several weeks to see results.
Use a Holistic Approach: This is one tool. Combine it with trigger management, good sleep, and stress reduction for the best results.