How We Research

Who writes this

Weralis is a small US home-comfort brand, and the guides are written in-house.

We are not doctors, veterinarians, chemists, or a testing lab, and we do not employ any. Nothing here is medical or veterinary advice. Where a question genuinely belongs to a clinician — a reaction, a diagnosis, a medication, a pregnancy, a pet that has swallowed something — the guide says so and stops, rather than guessing in a confident voice.

What we do have is a narrow subject we work in every day, and a rule about not writing past the edge of what we can show.

Where the numbers come from

Every figure in a guide traces to a named source, and the source is printed on the page rather than kept in a file somewhere. We use, in this order of preference:

Primary research and public-health bodies. Peer-reviewed studies indexed in PubMed and PMC, the US Environmental Protection Agency, the ASPCA Animal Poison Control Center, and comparable public bodies. When a study is cited, its identifier is on the page, so you can pull the paper and check that it says what we claim it says.

Manufacturer and supplier statements, labeled as such. A shelf-life figure from a bottler is that bottler's claim, and we present it as their claim, not as a physical constant.

Our own arithmetic, shown in full. Sometimes the number a reader needs does not exist anywhere, and it can be calculated from figures that do. When we do that, the inputs and the method are printed alongside the result.

What we do when the data is not there

This is the part that decides whether a page is honest, so it has rules.

An estimate is labeled an estimate. In the guide on diffusers and mold, we convert tank volume into humidity points using the saturation capacity of air at 20 °C and a stated air-change rate, and compare the result to the EPA's 60 % indoor humidity threshold. That is arithmetic from published constants, not a measurement taken in anybody's bedroom, and the guide says exactly that where the table appears. A calculation you can check beats a measurement you have to take on faith — but it is not the same thing as a measurement, and we do not let it wear that costume.

A range with a margin beats a precise number we cannot support. Where we publish a window rather than a figure, it is because the honest answer is a window.

Silence beats invention. If we cannot source it, it does not go on the page. There is no house style that fills a gap with a plausible-sounding sentence.

The conflict of interest, stated plainly

We sell diffusers, oil warmers, and sleep goods. Every guide on this site is written by a company with something to gain from you buying one. Pretending otherwise would be the least trustworthy thing on the page, so instead we hold ourselves to a test: the guide has to give the answer it would give if we sold nothing.

In practice that means our own writing argues against our own products where the facts do:

• The guide on diffusers and mold names the conditions under which our own Flame Mist Humidifier is the wrong object for the room, and says so before it says anything about buying one.
• The guide on sleep masks and dry eyes states that our contour mask does not hold the eyelids closed and is not a moisture chamber — the two things a reader with that specific problem most needs to know it will not do.

When the honest answer costs us the sale, the honest answer is the one that ships. That is not a slogan on this page; it is checkable against every guide we publish.

Review and correction

Each guide carries a “last reviewed” date, and that date means a person went back through the claims and the sources, not that a file was touched.

We correct in place and we do not correct quietly. When a figure turns out to be wrong, it is fixed on the page rather than deleted from it, because a reader who acted on the old number deserves to be able to tell that it changed.