Free tool · Built on FDA filings
The question it answers
How long would your mask need to give the same light as a clinical study?
Studies report how much light reached the skin in each session. Mask brands tell the FDA how strong their light is. Put the two together and you get a time, and you see why the same ten minutes can mean very different amounts of light on two masks.
This tool calculates how much dose a device delivers according to the specifications its manufacturer publishes. It is not medical advice and does not indicate what you should use.
Pick your mask
Search by brand, model or FDA number.
Pick a study
Each study used one colour of light. The calculator only uses your mask's mode of that same colour.
Read the time
How long one session on your mask takes to give the same light as one session in the study.
The mask you own or are looking at. Type a brand, model or FDA number.
The amount of light one session delivered in a published clinical trial. Its colour decides which of your mask's modes is used.
126 J/cm² per session · 9 sessions · Russell et al. 2005, PMID 16414908
Your result will appear here
Choose your mask above to see how long one session on it takes to give the same light as one session in the study.
Why this exists
Of the 60 LED face masks cleared by the FDA since 2021, 3 do not publish their irradiance anywhere — 5% of them. All three are Chinese ODMs with no consumer brand of their own.
Without that number there is no way to know how much light a device delivers in a session, however many LEDs or how much total power it advertises. For those devices the calculator returns no result and says so, rather than estimating one. That a manufacturer does not publish the figure is not a claim about the device or the brand: it means the number is not public.
The idea in one picture
Think of a glass of water and a tap. Tap each card to see what it stands for.
Example: the red-light wrinkle study against a mask whose red mode is declared at 16 mW/cm².
time (s) = target dose (J/cm²) × 1000 ÷ irradiance (mW/cm²)
Nothing else. There are no correction factors and no assumptions: if the manufacturer publishes its irradiance and the study publishes its dose, the time is a division. The hard part is not the arithmetic, it is getting hold of both numbers.
Your result
One session on your mask delivers the dose of one study session in that time.
The maker declares a range, several levels, or several readings for the study's colour, so the time is a band rather than one figure.
Your mask lists no mode we can identify as the study's colour of light. Timing a different colour would give a meaningless number, so none is shown.
The calculator returns no number, and does not estimate one from total power or LED count. That answer is as informative as a figure would be: it means nobody — not you, not us — can know how much light that device delivers in a session.
The device's FDA filing has not been processed yet, so its irradiance is not in our data. The gap is ours, not the manufacturer's.
Before you use the number
It is the time this device takes to deliver the dose of one session in that study. The manufacturer publishes its own instructions, and the device usually shuts off on its own before that.
The trials ran 8 or 9 sessions; home protocols are 4 to 7 per week over several weeks. The total can be comparable even when each session delivers less.
The photobiomodulation response is biphasic: small doses stimulate and large doses inhibit.
The studies used clinic panels, not masks resting against the face.
The studies
A clinical study is a published trial where researchers gave people a treatment, here LED light sessions, and measured their skin. The calculator compares your mask against one session of one of these two. Here is what each one did.
Clinical study 1 · 2005
Russell BA, Kellett N, Reilly LR. J Cosmet Laser Ther. 2005 · PMID 16414908
Its 2 options in “Study to match”, one per colour of light
Keep in mind: No randomised control group is described.
Clinical study 2 · 2006
Goldberg DJ, Russell BA. J Cosmet Laser Ther. 2006 · PMID 16766484
Its 2 options in “Study to match”, one per colour of light
Keep in mind: No control group, and microdermabrasion before each session.
Why only these two studies?
There are only four targets because we found only two trials that publish their fluence in J/cm². The two best-designed studies in the category — Lee 2007, double-blind with sham light, and Papageorgiou 2000, with 107 subjects and an active comparator — do not publish the dose in their abstracts, so they are not here. For rosacea there is no controlled trial with a published fluence, only case reports, which is why there is no rosacea target.
It is the same absence we point out in manufacturers, seen from the other side of the counter.