How to Evaluate Evidence Behind Cognitive Supplements

A practical evidence hierarchy

For a finished supplement, the strongest directly relevant evidence is a well-designed clinical trial of the actual finished formula. Next are trials of matching ingredients at matching doses. Mechanistic, animal and laboratory studies can generate hypotheses but are less directly predictive of real-world outcomes.

Questions to ask

• Was the actual finished product tested?
• Were participants similar to the intended users?
• Was there randomization and a placebo/control group?
• Were outcomes prespecified and validated?
• Was the dose comparable?
• Was the trial long enough?
• Who funded the research?

Ingredient evidence is not product evidence

A common marketing error is to cite a study on one ingredient and imply the finished blend is proven. That inference is not justified without matching dose, formulation and clinical testing.

Evidence red flags

Be cautious with dramatic disease-reversal claims, testimonials presented as proof, unpublished “studies,” fake doctor endorsements, or claims that the FDA has approved a dietary supplement for effectiveness.

References and further reading

1. U.S. FDA — FDA 101: Dietary Supplements