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CITED is a family of evidence-based supplement research sites. Every health claim on our sites is backed by peer-reviewed studies from PubMed, graded from A (strong evidence) to F (no evidence).

Unlike most supplement sites that rely on marketing claims, CITED grades every ingredient-condition claim using an algorithmic system based on study type, sample size, consistency of results, and overall direction of effect. Our data comes exclusively from PubMed-indexed, peer-reviewed research.

Yes, CITED is completely free. We earn revenue through affiliate links when you purchase products through our recommended links. Our editorial content and evidence grades are never influenced by affiliate partnerships.

CITED is operated by Cited Health Inc. Our team includes researchers with backgrounds in evidence-based medicine, data science, and health informatics. See our About page for more details.

Grade A means strong evidence from multiple clinical trials with consistent positive results. Grade B indicates moderate evidence from at least one well-designed trial. Grade C reflects limited but promising evidence. Grade D means only preliminary data exists. Grade F indicates no credible evidence or evidence showing no benefit.

An RCT is the gold standard of clinical research. Participants are randomly assigned to receive either the supplement being tested or a placebo. This design minimizes bias and provides the strongest evidence for whether a supplement works. Our grading system gives the most weight to RCTs and meta-analyses.

Evidence grades are recalculated whenever new research is added to our database. We regularly search PubMed for new studies on each ingredient-condition pair. A grade may change as new evidence emerges — both upgrades and downgrades are possible.

All our research data comes from PubMed and PubMed Central (PMC), the U.S. National Library of Medicine's databases of biomedical literature. We also use Semantic Scholar for citation data and ClinicalTrials.gov for trial registration information.

Direction of effect summarizes the overall trend across studies. 'Positive' means most studies found a beneficial effect. 'Mixed' means results were inconsistent across studies. 'Neutral' means no significant effect was observed. This helps you understand the evidence at a glance beyond just the grade.

Dietary supplements are regulated by the FDA under the Dietary Supplement Health and Education Act (DSHEA) of 1994, but not in the same way as prescription drugs. Manufacturers are responsible for ensuring safety before marketing. The FDA does not evaluate supplements for effectiveness before they are sold.

Yes, many supplements can interact with prescription and over-the-counter medications. For example, St. John's Wort can reduce the effectiveness of many medications. Always consult your healthcare provider before starting any supplement, especially if you take prescription medications.

Yes. We strongly recommend consulting a qualified healthcare provider before starting any supplement regimen, especially if you are pregnant, nursing, taking medications, have a chronic condition, or are under 18. The information on CITED is for educational purposes only and is not medical advice.

Look for products that are third-party tested by organizations like USP, NSF, or ConsumerLab. Check for appropriate dosages matching those used in clinical studies. Avoid products with proprietary blends that don't disclose individual ingredient amounts. Our product recommendations prioritize third-party tested options when available.

Navigate to the Ingredients page and find your supplement. Each ingredient page shows all conditions it has been studied for, along with evidence grades. Click on any condition to see the full evidence review, including individual studies and their findings.

Use the Compare page to see head-to-head comparisons. Select two ingredients and we will show shared conditions, unique benefits, evidence grades side-by-side, and whether they can be combined. Comparisons are generated dynamically from our evidence database.

Every page on CITED is available in Markdown format by adding .md to the URL (for example, /biotin.md). This provides a clean, structured text version designed for AI assistants, researchers, and anyone who prefers plain text.

When we recommend products, we include affiliate links to trusted retailers like iHerb and Amazon. If you purchase through these links, we may earn a small commission at no additional cost to you. Our evidence grades and recommendations are never influenced by affiliate relationships.