Red light therapy has quickly become one of the most popular at-home wellness treatments for pain relief, recovery, inflammation, and joint support.
From knee pain and back discomfort to muscle soreness and arthritis, more people are turning to red light therapy as a non-invasive alternative to medication and expensive clinic treatments.
But while the benefits get plenty of attention, many people still ask the same important question:
Are there any side effects of red light therapy?
The short answer is yes — but most are mild, temporary, and avoidable when devices are used correctly.
In this guide, we’ll cover:
- The most common red light therapy side effects
- Whether red light therapy is actually safe
- Who should avoid it
- How to use red light therapy safely at home
If you’re completely new to red light therapy, start with our full beginner guide:
Is Red Light Therapy Safe?
For most people, red light therapy is considered very safe when used properly.
Unlike UV light from tanning beds or sunlight, red light therapy does not damage the skin in the same way. Instead, it uses low-level red and near-infrared wavelengths designed to support cellular function and recovery.
Many people use red light therapy regularly for:
- Joint pain
- Muscle recovery
- Arthritis support
- Back pain
- Knee discomfort
- Inflammation
Most side effects happen because of:
- Overuse
- Sessions that are too long
- Devices being too close to the skin
- Extremely sensitive skin
- Poor-quality devices
In general, side effects tend to be mild compared to many pain relief alternatives.
Common Red Light Therapy Side Effects
Temporary Skin Redness
One of the most common side effects is mild redness after treatment.
This usually happens because red light therapy increases blood circulation to the treated area.
The redness is normally:
- Mild
- Temporary
- Gone within a few hours
People with sensitive skin may notice this more often, especially during longer sessions.
How to reduce redness
- Start with shorter sessions
- Keep the device at the recommended distance
- Avoid excessive daily use
Warmth or Tingling
Many users feel warmth during treatment.
This is usually completely normal and often a sign that circulation is increasing in the area.
Some people also experience:
- Mild tingling
- Slight tightness
- Temporary sensitivity
These effects typically disappear shortly after treatment ends.
Eye Strain or Headaches
Bright LED devices can sometimes cause eye discomfort if used incorrectly.
While red light therapy is generally safer than UV exposure, staring directly into powerful LEDs may lead to:
- Eye strain
- Temporary headaches
- Light sensitivity
This is more common with high-powered near-infrared devices.
Safety tips
- Avoid looking directly into LEDs
- Use protective goggles if recommended
- Position devices carefully around the face
Temporary Increase in Soreness
Some users notice slightly increased soreness after their first few sessions.
This can happen because blood flow and cellular activity increase in the treated area.
The sensation is often similar to mild post-workout soreness and usually improves with continued use.
This is especially common in people using red light therapy for chronic knee pain or lower back discomfort.
If you’re specifically using red light therapy for joint pain, these guides explain what results people commonly experience:
- Red Light Therapy for Knee Pain: Does It Actually Work?
- Red Light Therapy for Back Pain: Benefits, Results & Best Devices
If pain becomes severe or continues worsening, stop treatment and speak with a healthcare professional.
Dry Skin or Irritation
Some people experience mild skin dryness after frequent sessions.
This is uncommon but may happen if:
- Sessions are too long
- Treatments are too frequent
- Skin is already sensitive
To help avoid irritation
- Stay hydrated
- Use moisturiser after sessions
- Follow recommended treatment times
Can You Overuse Red Light Therapy?
Yes — and this is one of the biggest mistakes beginners make.
Many people assume longer sessions mean faster results, but excessive exposure can actually reduce effectiveness and increase irritation.
Overusing red light therapy may lead to:
- Skin sensitivity
- Temporary headaches
- Fatigue
- Reduced treatment effectiveness
For most home devices, moderate consistency works best.
Typical recommendations are:
- 10–20 minute sessions
- Around 3–5 times per week
If you’re unsure how often to use your device safely, read:
Who Should Avoid Red Light Therapy?
Although red light therapy is generally considered low risk, some people should speak to a doctor before using it.
This includes people who:
- Take medications that increase light sensitivity
- Have severe eye conditions
- Have epilepsy triggered by flashing lights
- Are pregnant
- Have active cancer or suspicious skin lesions
People with very sensitive skin should also begin with shorter, lower-frequency sessions.
Can Red Light Therapy Burn the Skin?
Burns are rare when using a quality device correctly.
Unlike tanning beds or lasers, red light therapy uses low-level light rather than intense heat.
However, problems may occur if:
- A device overheats
- Sessions are excessively long
- Cheap or poor-quality devices are used improperly
Following manufacturer instructions is important for safe treatment.
Are There Long-Term Side Effects?
Current research has not identified major long-term risks from proper red light therapy use.
Many people use red light therapy consistently for months or years without serious problems.
However, research is still developing around:
- Extremely long-term daily use
- Very high-powered commercial devices
- Excessive exposure durations
Using a reputable device and sticking to recommended session times is the safest approach.
How to Use Red Light Therapy Safely
Start Slowly
If you’re new to red light therapy:
- Begin with shorter sessions
- Treat one area at a time
- Increase frequency gradually
Consistency matters more than intensity.
Follow Device Instructions Carefully
Different devices vary significantly in:
- Power output
- Wavelengths
- Treatment distances
- Session recommendations
Always follow the guidance provided for your specific device.
Protect Your Eyes
Especially with facial treatments or stronger panels:
- Avoid direct LED exposure
- Wear goggles if advised
Don’t Expect Instant Results
One of the biggest misconceptions about red light therapy is expecting overnight improvement.
Most people need consistent sessions over several weeks before noticing significant changes.
If you want a realistic breakdown of what timelines to expect, read:
Final Thoughts
For most people, red light therapy is a safe and well-tolerated treatment when used correctly.
The most common side effects are usually mild and temporary, including:
- Redness
- Warmth
- Eye strain
- Mild soreness
- Skin dryness
The key is avoiding overuse, following safe session guidelines, and using a reliable device.
With consistent and moderate use, many people find red light therapy to be a helpful option for pain relief, recovery, and inflammation support without the harsher side effects associated with more aggressive treatments.