How a claim gets onto this site
Published 6 August 2026Zane Hitchcox, editor
Every statement about whether an ingredient works, or is safe, is traced to a named primary source and reported with the study's size and design attached. Where the source is weak, the page says so beside the claim. Nothing on this site is a product review, because nobody here has used any product.
What counts as a source
In descending order of what will be relied on:
- Systematic reviews and meta-analyses, Cochrane reviews first. These aggregate the trials and, importantly, report how confident the aggregate result deserves to be.
- Randomised controlled trials, cited with the number of participants, the comparator, the duration and the pre-specified outcome. A trial's control arm is usually where the interesting information is.
- Regulations, standards and regulator guidance, cited by instrument and number — the New Zealand Cosmetic Products Group Standard, AS/NZS 2604, Regulation (EC) No 1223/2009, the US Federal Food, Drug, and Cosmetic Act as amended. These are matters of fact, not of opinion, and they are checkable.
- Non-randomised, in-vitro and animal studies, used only to describe a mechanism and always labelled as such. A compound that kills bacteria in a dish has not been shown to do anything on a face.
What is not a source here: a brand's own marketing material, a press release, a supplier's technical sales sheet presented as research, a magazine article that does not name its study, or another blog. Where a claim can only be traced to one of those, the page says that the claim traces to one of those, which is itself useful information.
What the certainty labels mean
Every evidence card on this site carries a certainty label. These use the vocabulary of the GRADE framework, which is what Cochrane reviews use, and they describe confidence in the estimate of the effect — not how large the effect is.
| Label | Means |
|---|---|
| high | Further research is very unlikely to change the estimate. Rare in cosmetic science. |
| moderate | Further research is likely to have an important impact and may change the estimate. |
| low | Further research is very likely to change the estimate. Treat the number as provisional. |
| very low | Any estimate is very uncertain. Usually small, unblinded or short trials. |
| not established | No controlled human evidence exists for this claim at all. Frequently the honest answer for a botanical. |
A not established label is not an accusation that something does not work. It means nobody has run the study, and a reader is entitled to know that before spending money.
What this site does not do
- No product reviews, and no first-person experience. Nobody here has tested a product. No page will ever say "we tried this", "in our testing" or "after six weeks I noticed". Publishing a fabricated experience claim is unlawful in the United States under the Federal Trade Commission's rule on consumer reviews and testimonials, 16 CFR Part 465 — and it would make everything else on the site worthless anyway.
- No ratings, scores or rankings of products. Ingredients are explained; products are not graded. A reference that grades products acquires an interest in which products are graded well, and eventually becomes a shop.
- No affiliate links, advertising, sponsorship or sponsored posts. Nothing on this site earns a commission if you buy something, because there is nothing to buy and no link that pays. Should that ever change, the disclosure would appear next to the link itself, on every affected page, before anything else changed. That standard applies to the one interest this site does have: a single article cites a med spa's published prices, the publisher has an ownership interest in that business, and the disclosure sits in the same paragraph as the link rather than in a footer — which is the only placement the United States Federal Trade Commission treats as adequate.
- No medical advice. This is reference material about ingredients and regulation. It cannot diagnose anything, and it is not a substitute for a consultation. Skin conditions, persistent reactions and anything that is changing should go to a doctor or a dermatologist.
- No tracking. No analytics, no cookies, no third-party scripts, no fonts loaded from anyone else's server. See privacy. This is verifiable: view the page source.
Naming, spelling and units
Ingredients are given by their INCI name where a label would use one, with the common name alongside. Plant names in te reo Māori are written with macrons — mānuka, kānuka, tōtara — because that is how they are spelled, and the Latin binomial is given at first use. Measurements are metric. Money is in the currency of the jurisdiction being discussed and is labelled.
Corrections
Errors get fixed, and the fix is visible. If a factual claim on this site is wrong, write to [email protected] with the page and, ideally, the source. Substantive corrections are made in the text and noted at the foot of the article with the date. Silent edits to factual claims are not made; if the meaning changes, the change is recorded.
Two categories get particular priority. Anything that could affect a reader's health decision — a dose, a safety limit, an interaction — is treated as urgent. And anything concerning the former occupant of this domain, its founder or its trade marks will be actioned promptly; see about.
Dates
Every article carries the date it was published and, where it has been revised, the date of the revision. Regulation changes. The New Zealand cosmetic rules were amended in 2024 with obligations that began at the end of 2025, and the sunscreen regime changed in 2022. An undated page about a legal requirement is close to useless, so every page here is dated.