How we review supplements
Every review on FitnesSupps uses the same framework, so a 4-star product on one page means the same thing as a 4-star product on any other.
The product as it’s sold, for the job it claims to do.
A gut health formula is judged as a gut health formula, not against an energy drink.
When we’ve used it, we say so
Reviews note what we found on taste, mixability and day-to-day use. Personal use only informs the Fit for purpose score. One person’s experience isn’t evidence that a supplement works, so it never outweighs the research.
We don’t run lab tests
Beyond personal use, our assessments are based on the published label, the research on the ingredients, the manufacturer’s disclosures, regulatory records and current pricing.
What goes into every score.
Each product is scored from 1 to 5 on each criterion, in half points. The weights reflect what matters most when deciding whether a supplement is worth taking.
Evidence
The quality of research behind the key ingredients. Human trials count for more than lab studies, and trials on the finished product count for more than trials on single ingredients.
Formula and dosing
Whether key ingredients are present at the doses used in the research. Undisclosed amounts inside proprietary blends score lower.
Transparency
Full label disclosure, named probiotic strains, CFU counts guaranteed at expiry rather than manufacture, and independent testing.
Value
Cost per daily serving compared with products that do the same job.
Safety
Known side effects, notable interactions, suitability warnings, and any recalls, FDA warning letters or FTC actions.
Fit for purpose
Whether the formula makes sense for what it claims to do and for the people it’s aimed at.
From six scores to one rating.
Score each criterion
Every product gets a score from 1 to 5 on all six criteria.
Apply the weights
The six scores are combined using the weights above into a single figure.
Round to a half star
We round to the nearest half star. Exact quarter points round down, so nothing is rounded up by default.
Editor adjustment. An editor can move the calculated rating by up to half a star where the criteria miss something material, such as a strong formula that’s only sold on an auto-renewing subscription. When that happens, the review says so and explains why.
Four bands, in plain language.
Strong on evidence and formulation, with no significant drawbacks for its intended use.
A sound choice for its intended use, with limitations worth knowing about.
Suits some people, but there are meaningful trade-offs or better-supported alternatives.
We think most readers would be better served by another product.
We keep four things separate.
A study on an ingredient isn’t proof that a finished product containing it will work, and we don’t present it as such.
What the manufacturer says.
What the research actually shows.
What that research reasonably suggests.
Our editorial judgement, labelled as such.
Funded by commissions. Scored the same way regardless.
Affiliate links
If you buy through links on our site, we may earn a commission at no extra cost to you.
Ratings stay independent
Every product is scored on the same six criteria whether or not we earn from it. We also review products we have no commercial relationship with.
What it does influence
Affiliate availability affects which products we choose to review. We think you should know that.
Sources, updates and corrections.
Sources
Peer-reviewed research (mainly via PubMed), NIH Office of Dietary Supplements fact sheets, manufacturer labels, and FDA and FTC records. Every review lists its sources.
Keeping reviews current
Formulas, prices and offers change. We re-check a review when we learn of a change, and each review shows when it was last updated. Ratings can change as a result.
Spotted a mistake?
If you think we’ve got something wrong, contact us and we’ll look at it. See also our Editorial Policy and Advertising Disclosure.