Short answer: Most home red light sessions run 5–20 minutes. The exact number isn't arbitrary — it depends on how much light your panel actually delivers (irradiance, in mW/cm²) and how far away you sit. A stronger panel at a closer distance needs less time; a weaker one further away needs more. Longer is not automatically better.
Why there's no single correct number
What matters biologically is dose — the total light energy delivered to a given area, measured in joules per square centimetre (J/cm²). Dose is simply irradiance multiplied by time. That means two people can get the same dose from very different session lengths, depending on their panel and their distance from it.
This is why “10 minutes a day” advice on its own is close to meaningless. Ten minutes in front of a weak panel at a metre away is a completely different dose from ten minutes at 15cm in front of a full-body panel. Without knowing the output figure, the time is only half the equation.
A practical starting point
For general home use with a panel that publishes a measured output in the region of 40–100 mW/cm² at 15cm:
- Getting started: 5–10 minutes per area, at 15–30cm.
- Settled routine: 10–20 minutes per area.
- Frequency: daily or every other day is the pattern used in most home routines.
If you're treating several areas — say back, then knees — count the time per area, not in total. A larger panel covers more at once, which is the main practical reason people move up a size: the whole session gets shorter.
More is not better — the biphasic response
One of the most consistent findings in the photobiomodulation literature is a biphasic dose response: effects build with dose up to an optimum, then flatten and can reverse if you keep pushing. Doubling your session time doesn't double anything. It's one of the few points where the research is unusually consistent, and it's the reason manufacturers publish session guidance rather than saying “use as long as you like.”
Practically: if you're unsure, err shorter and more regular rather than longer and occasional.
Distance changes everything
Light intensity falls off sharply as you move away from the panel. Sitting at 30cm instead of 15cm can substantially reduce the irradiance reaching your skin — which means the same session length delivers a much smaller dose.
So when you read any output figure, check the distance it was measured at. A number quoted without a distance tells you nothing, and a reading taken at the LED surface will always look impressive while bearing little relation to what reaches you at a normal sitting distance.
How to work out your own timing
- Find your panel's measured irradiance at a stated distance. If the manufacturer doesn't publish one, that's worth noticing.
- Decide your working distance and stick to it — consistency matters more than precision.
- Start at the shorter end (5–10 minutes) for a couple of weeks.
- Adjust gradually, and keep it regular rather than chasing long sessions.
Every Red Light Fix RLF panel publishes its spectrometer-tested output at a stated 15cm distance — from 82 mW/cm² on the compact RLF750 up to 92 mW/cm² on the RLF6000 — so you can work out your own timing rather than guess.
Frequently asked questions
Is 30 minutes better than 10?
Not necessarily. Because of the biphasic dose response, going well past the optimum tends to flatten or reduce the effect rather than increase it. Longer sessions are not a shortcut.
Can I do red light therapy every day?
Daily or every-other-day short sessions are the typical home pattern. Consistency over weeks matters more than any single long session.
Does distance or time matter more?
They work together — dose is irradiance multiplied by time, and irradiance depends heavily on distance. Fix your distance first, then set your time around it.
Should I use goggles?
Red light panels are bright. Use the eye protection supplied, or simply avoid looking directly into the LEDs during a session.
This article is general information about using light therapy devices and is not medical advice. If you have a health condition or are unsure whether red light therapy is suitable for you, speak to a qualified healthcare professional.