Data updates
What actually changed in our catalog, cost-per-unit method and pages — dated, so you can see the site is maintained rather than take our word for it. Coverage counts below are live; the log records data and coverage events, never prices.
Most recent change: . Coverage refreshed every 30 minutes.
- New pages
Added a GLP-1 companion goal hub — the supplements people on semaglutide/tirzepatide ask about (protein, magnesium, electrolytes, fibre, B12, D), ranked by cost per dose. A value comparison, not medical advice.
- Data quality
Cross-checked every catalog brand against the official public registries. Seven brands hold a verifiable independent certification (USP Verified, NSF Certified for Sport, or Informed Choice) — each now links to its registry entry. Unverifiable "tested" labels were removed; GMP-only brands are no longer marked as third-party tested.
- New pages
Published a guide: “Third-party supplement testing explained” — what USP, NSF, NSF Certified for Sport and Informed Sport each test, and why “GMP certified” is not the same thing.
- Data quality
Quarantined 158 deals whose scraped price had glitched below a plausible floor, and added a durable guard so a sub-$1 glitch can no longer surface as a “best value” pick or skew the studies.
- Method
Tightened the cost-per-dose studies: omega-3 is no longer normalized on total fish-oil weight (only the active EPA+DHA basis), and multivitamin/prenatal/pre-workout blends are excluded from single-nutrient cost percentiles.
- New pages
Added elemental-content “true cost” tables to the mineral hubs and form-comparison pages — a 1,000 mg magnesium oxide capsule delivers far more elemental magnesium than a 1,000 mg glycinate one, so the label number alone is misleading.
- New pages
Added “What the evidence shows” sections and a “does it actually work?” answer to the nutrient hubs, quoted and cited from the NIH Office of Dietary Supplements and NCCIH.
- New pages
Published the /research studies — the supplement price-spread study and the form-premium study — with the underlying figures released free to cite (CC-BY).
- Method
Gram-dosed categories (protein, creatine, collagen) are now ranked by cost per gram of active, not per scoop, so a bigger scoop can’t look like better value.
- Coverage
Deepened the nutrient hubs with NIH-sourced food-source, deficiency and safety sections across the catalog.
Why no prices in this log? Cost per unit is our metric, but the raw retailer prices behind it are the retailer’s — we don’t redistribute them or track them over time. How we compute the numbers is on the methodology page.