Supplement Brief is an editorial site, not a laboratory. We do not run chemical assays on the products we cover. Running a single category through third-party lab testing at meaningful sample sizes costs roughly $50,000+ per year, a budget we do not currently have. This page states what we actually do, what we explicitly do not do, and where you can find independent laboratory data when you need it.
What we do
- Label and specification review: we read the supplement facts panel, form (e.g. magnesium bisglycinate vs. oxide), dose, excipients, and any third-party certifications disclosed by the brand (NSF, USP, Informed Sport).
- Bioavailability and form check: we compare the product's active form against the form used in cited human trials. A label claim and a clinically studied form are not the same thing.
- Clinical-evidence audit: each guide starts with a PubMed, Cochrane, and specialty-journal scan. We rank by what the published studies actually measured: dose, duration, population, primary outcome, and effect size. When human data is thin, we say so in the guide rather than hiding behind marketing language.
- Claims-versus-evidence review: we check whether the brand's marketing claim matches the cited research. The most common failure mode in this category is a single small trial being extended into a broad consumer claim.
- Safety and medication-context review: we flag known interactions, common adverse events from trial data, and categories where prescription medication context matters (GLP-1 companions, berberine, St. John's Wort, etc.).
- Evidence hierarchy: we rank every cited study by tier and name weaker tiers in the article body, not only in the references. See how we order evidence below.
- Industry-funded trial flagging: when a cited trial is funded by the company whose product is being studied, we name the funder in the article body. Industry funding does not invalidate a trial, but it is a documented source of effect-size inflation and selective reporting, and it is part of the evidence the reader is entitled to.
- Public trial predictions: we publish dated, falsifiable claims about pending trial readouts on our predictions ledger before results land, and score them when readouts publish. That is evidence tracking, not medical advice.
- PMID-verified citations: where a cited study has a PubMed identifier, we link to the PubMed record (for example, pubmed.ncbi.nlm.nih.gov/22552758) so the reader can open the abstract directly and verify the claim against the source. We do not invent PMIDs or DOIs: every identifier we publish is checked against PubMed before publication, and any citation that cannot be located in PubMed under the names used in popular summaries is rejected in favour of a verifiable source.
- Counter-evidence reporting: we do not cherry-pick the studies that support a supplement. When trials are mixed, negative, or fail their primary endpoint, we report that in the article body alongside the positive data, not only in the references. A reader should be able to tell from the article whether the evidence leans one way or is genuinely split.
- Population-gap and sex-specific callouts: when the human evidence for a supplement is drawn from a single sex, a narrow age band, or a specific population (e.g. postmenopausal women, men with confirmed androgenetic alopecia), we name that limitation in the article body. We do not generalise mixed-population or single-sex results to “people” without flagging the gap.
- Reader-checkpoint safety callouts: articles that touch medication context (GLP-1 agonists, antidepressants, antihypertensives, blood thinners) carry a prominent safety callout near the top of the guide. For example: “Do not stop your antidepressant to try a supplement.” Safety information is placed where a reader is likely to see it before acting, not buried at the bottom.
Evidence hierarchy
Every guide maps cited studies onto the tier scale below. When a guide relies on lower-tier evidence (small trials, preclinical data, or a single industry-funded study), we label that limitation in the article body, not only in the references.
What we do not do
- We do not run chemical assays: no heavy-metal testing, no label-accuracy testing, no dissolution profiling. We are not equipped for it and do not claim to be.
- We do not accept paid placement. Rankings are not for sale. A brand cannot pay to appear higher in a guide.
- We do not present supplements as replacements for prescription medication. Articles that compare a supplement to a prescription drug (e.g. berberine vs. Ozempic) explicitly frame the supplement as a different category with different evidence.
- We do not publish miracle claims, before/after promises, or fake medical-review badges.
Where to find independent lab data
If you need chemical analysis of a specific product (label accuracy, heavy metals, microbial contamination, dissolution), the following independent organisations publish it. We have no commercial relationship with any of them.
- Labdoor: independent quality and label-accuracy testing for popular supplement brands.
- ConsumerLab.com: subscription-based independent testing across supplement categories, vitamins, and herbals.
- USP (United States Pharmacopeia): verification program for products that meet USP standards for identity, potency, purity, and performance.
- NSF Certified for Sport: third-party certification covering banned-substance screening and content verification.
Medical review
Daniel Hart, the editor, is not a physician, pharmacist, or dietitian. Articles in categories with significant medical context (GLP-1 companions, berberine, prescription-vs-supplement comparisons) are reviewed against cited sources and Supplement Brief editorial standards. When a named clinician or credentialed specialist reviews an article, that review is stated separately in the byline.
Our first external medical reviewer is Natallia Kalistratava, MD, a general practice physician licensed in the Republic of Belarus. She reviews selected guides for clinical accuracy, safety framing, and alignment with cited peer-reviewed sources. Her profile states what she does and does not cover (for example, she is not an endocrinologist, urologist, or psychiatrist). Scope for the weight loss support hub is on that page; other guides note review in the byline. We will add reviewers here as additional relationships are formalised.
Updates and corrections
Guides are updated when new trial evidence, safety information, or clinical review scope changes. Major updates are reflected in the guide date shown on each article page. Material corrections and significant pre-publication fact-check rejections are listed on the corrections page. If you find a factual error, email [email protected] and we will review and correct.