Our Methodology
Every recommendation on Supplement Science is backed by a transparent, evidence-based evaluation process. We believe you deserve to know exactly how we arrive at our conclusions — so here it is.
Research Process
Our editorial team reviews peer-reviewed clinical studies, meta-analyses, and systematic reviews from databases including PubMed, Cochrane Library, and Examine.com. We prioritize:
- Meta-analyses and systematic reviews over individual studies
- Randomized controlled trials (RCTs) over observational studies
- Human studies over in vitro or animal research
- Recent research (last 5 years) alongside foundational studies
Every ingredient page includes direct citations to PubMed-indexed studies. We never fabricate references and we link to the original source whenever possible.
How We Rate Products
Product comparisons use a weighted scoring methodology. Every product is evaluated against the same criteria, and scores are calculated transparently. Our standard evaluation weights are:
Third-Party Testing
30%Independent lab verification (NSF, USP, ConsumerLab, or equivalent) confirming purity, potency, and absence of contaminants.
Dose Adequacy
25%Does the product deliver clinically studied doses? We compare label doses against effective doses from published research.
Bioavailability
20%Is the ingredient form well-absorbed? We prioritize forms with demonstrated superior bioavailability (e.g., chelated minerals, methylated B vitamins).
Value
15%Cost per effective serving — not just sticker price, but the actual cost of getting a therapeutic dose.
Clean Label
10%Minimal artificial additives, no proprietary blends hiding doses, transparent ingredient sourcing.
Individual product comparisons may adjust weights when category-specific factors matter (e.g., strain diversity for probiotics, EPA:DHA ratio for omega-3s). Adjusted weights are always shown on the comparison page itself.
Editorial Independence
Our editorial process is structurally separated from our revenue model:
- Product rankings are determined by our scoring criteria, never by business partnerships
- We include non-affiliate budget picks in every comparison when they deserve a recommendation
- 30% of our content (research summaries, learn articles) carries zero affiliate links
- We publish negative findings and honest drawbacks for every product reviewed
- All affiliate relationships are clearly disclosed at the top of relevant pages
Affiliate Disclosure
Supplement Science is supported through affiliate commissions. When you purchase a product through one of our links, we may earn a small commission at no extra cost to you. As an Amazon Associate, we earn from qualifying purchases.
This revenue funds our research team, hosting infrastructure, and keeps all our content free and accessible. It never influences which products we recommend, how we rank them, or what we write about them.
If we cannot find a product worth recommending in a category, we say so directly rather than recommending an inferior product with an affiliate link.
Updates & Corrections
We review and update all content regularly to reflect new research, product reformulations, and price changes. When we discover an error, we correct it promptly and note the change.
Found an error or have a suggestion? Contact us — we take accuracy seriously and appreciate corrections from our readers.