How we check our data
GlowSpec compares prices, published specifications, available third-party measurements and FDA status for 60 at-home beauty devices. This page explains where each figure comes from and what each label means.
The short version
- We don't run a lab. GlowSpec doesn't test devices. Measurements on the site come from outside sources, and we name who reported each one.
- We don't estimate missing values. If we can't source a figure, we leave it blank and say so. Unit conversions and simple arithmetic on published figures are labelled; they aren't estimates.
- Every price has a source type and a check date. Prices change often, so always confirm on the store's page before you buy.
- Brand claims and third-party measurements are shown separately. A listed spec isn't proof that a device works.
- An FDA label tells you what records we found, not how well a device works. FDA-cleared is not FDA-approved.
- Not medical advice. We don't recommend treatments or claim that any device treats, cures or prevents a condition.
Data last checked Nov 1, 2026.
Three kinds of source
We keep these apart throughout the site:
- Original sources: the brand's own store or product page, a retailer's product page, and the FDA's own database. These are where a price, a spec or a record actually comes from.
- Reported measurements: a light-power reading published by a reviewer, a testing lab or a brand-commissioned lab. We report what they published and who published it. We didn't take the reading.
- Third-party datasets and trackers: collections compiled by someone else, such as Outliyr's open dataset (CC BY 4.0), camelcamelcamel's Amazon price history and openFDA. We label which dataset a figure came from.
Prices
Each price on a device page shows the store, the date we checked it and one of the source types below. The number in brackets is how many price rows currently use that type.
- Brand store data (49)
- The price in the brand's own online store data on the check date. This is an original source.
- Retailer page (13)
- We opened the retailer's product page on the check date and read the listed price.
- Retailer catalog (14)
- The price in the retailer's product catalog listing on the check date. We didn't open the product page itself, so treat it as slightly less direct than a retailer page.
- Shopping listing, unconfirmed (2)
- A price from a shopping search result that we couldn't confirm on the store's page. We label it "unconfirmed" wherever it appears and list it alongside any confirmed prices. Confirm it on the store's page before relying on it.
- Price tracker (1)
- An Amazon price reported by camelcamelcamel, a third-party price tracker, shown with the date it reported. We use it for one device so far. We don't track price history ourselves.
- Third-party review (2)
- A price recorded by a review site, currently microneedlingreview.com, on its own check date. We use it only when we couldn't check the store ourselves, and the device page says so.
Price history
Most devices have no price history on GlowSpec. Where a device page shows one, it comes from a named outside source: camelcamelcamel's Amazon history for one device, and a dated sale article for another, labelled "not a current price".
Deals
A deal appears on GlowSpec only if we saw the sale price on the store's own page, or the store showed both a sale price and a regular price. Bundles are compared with the separate prices where we could check.
A current sale price isn't automatically a price drop. The comparison price is the one the store lists. We haven't tracked how long the device sold at that price. Discount codes, member pricing and in-cart promotions usually don't show in listed prices.
Light power: brand claims and third-party measurements
Irradiance is how much light power reaches each square centimetre of skin, in milliwatts per square centimetre (mW/cm²). Wavelength is the colour of the light, in nanometres (nm).
On each LED device page we show two things side by side:
- Power claimed: the brand's own figure, with its distance and method when the brand states them, and a link to where it says so.
- Power measured: every available third-party measurement, with who reported it and a link. If there's none, the page says "No third-party measurement found yet."
Measurements currently come from these sources (5 devices have at least one):
- IrradianceLab, an ISO/IEC 17025-accredited testing lab that publishes its results. We also note devices it lists as queued for testing.
- Spectrometer tests by Light Therapy Insiders, as reported by Longevity Intel.
- A spectrometer test as reported by Evident Reviews.
- Lab reports a brand commissioned and published itself, such as Mito Red's LightLab International reports. We label these "commissioned by" the brand.
We also use Outliyr's open dataset as a third-party compilation. On the site today it supplies one brand-claimed figure (labelled "as compiled by Outliyr"), not a measurement.
When sources disagree, we show every result. Higher power isn't automatically better, and a listed spec isn't proof that a device works.
Calculating a session's light dose
Light dose (fluence) is irradiance multiplied by time:
dose (J/cm²) = irradiance (mW/cm²) × session length (seconds) ÷ 1,000
For example, 50 mW/cm² for 600 seconds (10 minutes) is 30 J/cm². This is arithmetic on two published figures, not an estimate, and it's only as good as the figures you put in. A brand's claimed irradiance and a third-party measurement will give different doses.
GlowSpec doesn't currently show a calculated dose on device pages. If we add one, we'll show which irradiance figure and session length we used.
Hair-growth devices
For helmets, caps, headbands and combs we list the device type, the light source (laser diodes, LEDs or both), the diode count, wavelengths, the brand's session guidance, cordless or plug-in, the warranty and any money-back terms.
All of these come from the brand's own product page, which is linked on each device page. We don't have third-party measurements for hair devices. A higher diode count doesn't by itself mean better results. Brand guarantees usually have conditions, so read them on the brand's site.
Multi-function wands
Wands that combine light with warmth, a low-level current or vibration have their own category, because they aren't simply microcurrent or LED devices. We list each technology the brand names, plus wavelengths, battery life and session guidance from the brand's page.
LED body panels: size and power
Size is the panel's own height: its long side, not including any stand or mount. It comes from the brand's spec page or comparison chart. We show it in inches and centimetres, with full dimensions on each device page.
Where a brand publishes only one unit, we convert it (1 inch = 2.54 cm) and say so on the device page, for example "Brand spec is 900 mm; inches converted by GlowSpec." A conversion isn't an estimate.
Power: panel brands usually publish irradiance measured with a handheld solar meter at 6 inches. In the third-party measurements we currently use, spectrometer readings of the same panels have often come in at roughly half the brand's figure. That isn't true of every panel. Claimed and measured figures differ because instruments and distances differ, so compare figures taken at the same distance. We don't adjust or convert readings between instruments or distances.
Product images
Product photos come from each brand's own product page: usually the main product photo in the brand's store data, otherwise the main photo on the page or the page's share image. We resize and host them on GlowSpec, and link the source page under each photo.
58 of 60 devices have a brand photo. Where we couldn't get one, the page says "No brand image available".
FDA status
We look up each device in the FDA's 510(k) database (also available through openFDA). A 510(k) is the FDA's premarket notification route: a cleared 510(k) means the FDA found a device substantially equivalent to one already on the market, for a specific labelled use.
We match by brand, product name and model number. Many devices are filed under the manufacturer's legal name or a model code rather than the retail name, so a match sometimes needs more checking. When we match a record, the device page links it and shows the 510(k) number.
FDA-cleared is not FDA-approved. Clearance and approval are different FDA processes.
| Label | What it means | What it doesn't mean | Devices |
|---|---|---|---|
| FDA-cleared | We matched this product to a 510(k) record in the FDA's database. The record is linked. | It's a regulatory record for a labelled use, not a performance guarantee. It isn't FDA approval. | 19 |
| Cleared, Rx only | The FDA record shows a clearance for prescription or professional use. | It doesn't mean the device is cleared for ordinary at-home use. | 1 |
| Brand says cleared | The brand or a retailer says the device is FDA-cleared, but we haven't matched this exact product to a 510(k) record. | It isn't the same as a matched record. The claim may be true; we just haven't confirmed it. | 17 |
| Not FDA-cleared | A documented source says the device isn't cleared. For microneedling pens we rely on the FDA's consumer guidance and microneedlingreview.com's clearance lookup. | It's a status from that source, not a test result. | 7 |
| No clearance found | We searched the FDA's database by name and no matching record was found. | It's a search result, not proof that no clearance exists. A record may be filed under another name. | 16 |
FDA status is about regulation, not effectiveness. It doesn't tell you whether a device will work for you.
What we don't do
We don't make medical claims, recommend treatments for conditions, or cover injectables or prescription drugs. For anything that pierces the skin or treats a condition, talk to a licensed clinician.
Corrections
When we find an error in a price, spec or FDA status, we correct the data and rebuild the site. A public way to report errors isn't set up yet; when it is, we'll list it here.
The data file
Everything on the site is built from one file you can download: devices.json. It holds every device, price, source link and FDA record we use.
Data last checked: Nov 1, 2026.