Red light therapy
side effects
Every side effect explained in plain English. What it feels like, why it happens, and exactly what to do about it.
One of the Safest Therapies We Offer
Red light therapy (photobiomodulation) uses specific wavelengths of red and near-infrared light to support cellular function. It is one of the safest therapies we offer. Side effects are rare and mild.
This guide covers what you might notice so you are fully informed. We take even small things seriously — because transparency builds trust and helps you get the most out of every session.
Mild Skin Redness
What It Feels Like
The treated area may appear slightly pink or flushed immediately after a session. Like a very mild sunburn appearance without the pain. It is not uncomfortable — just noticeable. Usually fades completely within 30-60 minutes.
Why It Happens
Red and near-infrared light increases blood flow to the treated area. More blood flow means temporarily pink skin. This is actually the intended mechanism — increased circulation is exactly how the therapy works. The redness is visible evidence that your body is responding to the treatment.
What to Do
Increased blood flow is exactly what the therapy is designed to do. The temporary pink flush is a sign that your cells are receiving the light energy and responding. It is a feature, not a side effect.
Eye Strain or Sensitivity
What It Feels Like
Eyes feel sensitive, a slight headache behind the eyes, or temporary brightness sensitivity after a session. Similar to looking at a bright screen for too long. Some people notice that indoor lighting seems slightly brighter than usual for a short period after treatment.
Why It Happens
Red and near-infrared light is very bright. Direct exposure to high-intensity light can cause temporary eye fatigue, just like staring at a bright screen. The light panels emit concentrated wavelengths that, while therapeutic for skin and tissue, are too intense for unprotected eyes.
What to Do
Proper eyewear eliminates this entirely. We provide goggles at every session and our staff will always make sure you have them on before starting treatment. This side effect only occurs when eye protection is not used correctly.
Mild Warmth or Tingling
What It Feels Like
A gentle warm sensation on the skin during treatment. Some people feel a slight tingling, especially in areas with more blood flow close to the surface. It should feel pleasant — like standing in gentle sunlight. The warmth is mild and should never feel hot or uncomfortable.
Why It Happens
The light energy is absorbed by your cells and partially converted to heat. Near-infrared wavelengths penetrate deeper into tissue and generate slightly more warmth than red wavelengths. The tingling is from increased circulation as blood flow increases to the treated area.
What to Do
The therapeutic effect depends on light absorption, and some warmth is a natural part of that process. Think of it as confirmation that the light is reaching your cells and doing its job.
Temporary Tightness or Dryness
What It Feels Like
Skin may feel slightly tight or dry in the treated area after a session, similar to how skin feels after mild sun exposure. It is not painful — just a mild tightness that you might notice when you move or stretch the skin. Usually resolves within a few hours.
Why It Happens
The light energy can temporarily reduce surface moisture on the skin. The mild heat from the light panels can also contribute to slight dehydration of the outer skin layer. This is minor and self-correcting — your skin naturally rehydrates within a few hours.
What to Do
A simple moisturizer is all you need. Many patients actually notice improved skin texture and tone with consistent sessions — the temporary tightness gives way to healthier-looking skin over time.
Fatigue or Deep Relaxation
What It Feels Like
Feeling sleepy, deeply relaxed, or mildly fatigued after a session. You might feel like you just had a great nap or a deep massage. Some people experience the opposite — a noticeable energy boost. Both responses are normal. The effect can vary session to session.
Why It Happens
Red light therapy affects mitochondrial function and can promote parasympathetic nervous system activation — your body's "rest and repair" mode. The deep relaxation response is actually part of the therapeutic benefit. Your body is shifting into recovery mode, which is exactly what the therapy is designed to support.
What to Do
Both fatigue and energy are normal responses. Your body is using the light to support cellular repair. The relaxation you feel is your nervous system shifting into recovery mode — which is exactly what we want.
Headache
What It Feels Like
A mild headache during or after a session. Not common and usually related to dehydration, eye strain from not wearing goggles properly, or being sensitive to bright environments. It should not be severe. Most people who experience it describe it as a dull, mild ache that resolves within an hour.
Why It Happens
Usually from inadequate hydration before the session, eye exposure from not wearing goggles properly, or being in a warm room without enough water. The bright light environment can also trigger mild headaches in people who are sensitive to bright settings — similar to how some people get headaches from fluorescent lighting.
What to Do
Hydration and proper eye protection prevent this for nearly everyone. If you have experienced a headache after a session, try arriving well-hydrated with a properly fitted pair of goggles — that alone fixes the issue in most cases.
When to Contact Us
Red light therapy side effects are rare and mild. But we want you to know exactly when to reach out.
Call Us Right Away
- Skin burns, blistering, or prolonged redness (extremely rare — indicates equipment issue)
- Persistent vision changes after a session
- Any allergic-type reaction (hives, swelling, difficulty breathing)
Schedule a Check-In
- Recurring headaches after sessions
- Skin dryness that is not improving with moisturizer
- Questions about your protocol
- Want to adjust session length or frequency
Medication Note: If you are taking any photosensitizing medications — certain antibiotics, retinoids, or other medications that increase light sensitivity — tell us before starting red light therapy. These can make your skin more reactive to light and may require protocol adjustments.
Important: This guide is for Range Medical patients receiving red light therapy (photobiomodulation). It is not a substitute for personalized medical advice. All sessions are supervised by trained staff. If you are experiencing any unexpected reaction, contact us immediately.
Questions? We Are Here.
Whether you want to adjust your protocol, have questions about what you experienced during a session, or just want to talk through something — our team can help.
1901 Westcliff Dr. Suite 10, Newport Beach, CA 92660