Evidence review · Published by Northbank Media

We grade the evidence, not the marketing

An independent review of natural ingredients, immunity and preventative skin health. Every claim gets a qualitative evidence grade, and when a popular ingredient turns out to rest on very little, we say so on the page rather than in a footnote.

The four grades

Grades attach to claims rather than to ingredients, which is why a single ingredient can carry several of them.

  • Strong evidenceMultiple independent controlled trials in people, consistent in direction, with a mechanism that holds up and replication outside the funding party.
  • Moderate evidenceSeveral controlled human trials, but typically small, short or narrow in who was studied. Direction is fairly consistent; size and durability are not settled.
  • Limited evidenceHuman evidence exists but is thin: small, short, single-site, mostly funded by parties with an interest, or leaning on laboratory and animal work.
  • Insufficient evidenceLittle or no controlled human evidence for the claim as made. The idea may be biologically reasonable and still be untested at the level being sold.

The reviews

Eight ingredients and topics, each opening with an evidence grade and a claim-versus-evidence table. Three of them carry grades their markets will not enjoy.

See the index
Moderate evidence

Topical vitamin C

Strong laboratory rationale, a thin and short human trial base, and a formulation problem that most of the marketing quietly ignores.

Read the review
Strong evidence

Retinoids

The one topical category where the human trial base is deep enough to justify the confidence. Also the one most people abandon before it works.

Read the review
Moderate evidence

Niacinamide

The most tolerable active in common use, with a plausible mechanism and a human trial base that is broader than it is deep.

Read the review
Limited evidence

Collagen supplements

One of the fastest growing supplement categories in the UK, resting on a trial base whose funding pattern should give any reader pause.

Read the review

What this publication does

Four commitments that between them describe the whole editorial position.

One

Grade qualitatively

No scores out of ten. Four named grades describing the depth, consistency and independence of the human research behind a claim.

Two

Never invent specifics

No fabricated author, journal, sample size, p-value or effect size appears here. We describe the shape of an evidence base, which is what can be stated without misrepresenting it.

Three

Grade claims, not ingredients

An ingredient can be essential in deficiency and useless above it. Both are true, and collapsing them into one verdict destroys the information you needed.

Four

Say when it is weak

Several categories reviewed here have very large markets behind them and carry Limited grades. We would raise them if the evidence arrived.

Method and context

Four pages that make the rest of the site usable: what the grades mean, how to read research yourself, why natural is not a safety claim, and what UK law actually requires of a supplement.

How we grade evidence

Four grades, applied to claims rather than to ingredients, with the reasoning shown.

Why natural does not mean safe

The reasoning error this publication exists to correct, set out with the cases where it has caused harm.

Supplement regulation in the UK

The regulatory reality behind the shelf: what has been checked, what has not, and what the wording on the label is doing.

Reading a study

Nine questions that will tell you more about a study than the headline ever will.

Independence, stated plainly

No advertising. No affiliate commission. No sponsored content. No samples accepted. No company previews a grade or can have one changed. We do not review named brands or products at all, which removes the mechanism by which a review site becomes a shop.

There is one disclosed exception and we declare it rather than bury it: four archive articles each carry a single editorial link, placed by our own writers and never sold, and each of those pages carries a publisher disclosure block naming Northbank Media. Every other page carries no commercial link and says so. The full position is in the editorial policy.

Subscribe to grade changes

We email when a grade is revised, a new review is published, or a regulator does something that alters the picture.

We email when a grade changes or a new review is published. Nothing else, and no product recommendations, because we do not make any.