RESEARCH, IN CONTEXT
A clearer supplement comparison
Use this free worksheet before buying a vitamin, fitness supplement or longevity product.
Published November 7, 2026 · Source-researched editorial; no independent clinician review.
Your notes remain on this page and are not uploaded by this tool or saved after a reload. Print to keep a copy. Avoid putting sensitive medical details into a shared-device worksheet.
1. Purpose
What specific need am I trying to address? Is a deficiency or medical indication involved?
2. Exact product
Record brand, product name, ingredient form, amount per serving and servings per container.
3. Evidence
Does a human study test this ingredient or product, in a relevant population, for an outcome that matters?
4. Quality
Verify any independent certification for this exact product. Request relevant batch testing where available. Quality testing does not prove benefit.
5. Interactions
List medicines and other supplements for a clinician or pharmacist to review. Count overlapping ingredients.
6. Cost
Record the full delivered price, servings used per month, subscription renewal price and cancellation terms.
7. Decision
What would make me buy, wait or stop? Who will help assess whether the product is appropriate?
A quick cost example
A fictional $36 container with 30 servings costs $1.20 per serving before any extra delivery charges. If the planned use is 30 servings monthly, the monthly product cost is $36. This example is arithmetic, not a recommended dose or a current product price. Compare renewal pricing as well as introductory discounts.
Ordinary links for your research
iHerb and Life Extension: broad catalogs. Ritual and Thorne: compare specific formulas rather than assuming a brand-wide benefit. Timeline: read our urolithin A evidence guide. Tru Niagen: read the NR evidence guide.
These are ordinary links, not currently represented as commission-earning links. No company paid for its position in this list. Our separate Beauty Shop labels its paid links. A higher price or commission never establishes a medical benefit.
What FDA regulation means
Dietary supplements are not generally approved by FDA for safety and effectiveness before marketing. Manufacturers and distributors have responsibilities for safety and lawful labeling. “FDA registered” is not the same as product approval. A supplement should not be marketed as a cure or substitute for appropriate treatment.
Source
Educational information, not individualized treatment advice. No supplement or spa experience here is established to reverse human aging.
Explore the evidence desk ↗