The fisetin supplement market has grown rapidly alongside senolytic research, with significant variation in product quality. Key differentiators are fisetin purity (target ≥98%), bioavailability enhancement (phytosome or liposomal vs standard extract), dose per capsule (higher doses reduce pill burden), and third-party testing for heavy metals and label accuracy.

How do I verify fisetin supplement quality?

Request the Certificate of Analysis (CoA) from the manufacturer. Key values to check: fisetin assay (should match label claim), heavy metals (lead <0.5 ppm, cadmium <0.1 ppm), and microbial testing (negative for pathogens).

Is there a difference between Japanese and Indian sourced fisetin?

Both use Sophora japonica or Cotinus coggygria as primary botanical sources. Quality depends on extraction and purification standards, not geography. Novusetin® (sourced from Sophora japonica, standardized to ≥98%) is the benchmark.