In plain terms: Fisetin has not yet been tested in a human trial designed to measure the outcome relevant here. The available human research does not yet answer the question.
Fisetin
The evidence as the record states it
Yousefzadeh et al. (EBioMedicine, 2018; PMID 30279143): fisetin acts as a senotherapeutic extending health and lifespan in MICE; mouse data only. Human trials exist in other uses, none of them senolytic: Hodgin et al. (Int J Environ Res Public Health, 2021; PMID 33802381): placebo-controlled crossover of botanical agents including fisetin in Gulf War illness; no symptom benefit. Farsad-Naeimi et al. (Food Funct, 2018; PMID 29541713): 37 colorectal cancer patients on chemotherapy, 100 mg/day for 7 weeks; IL-8 lower than placebo, other markers not. Alipour et al. (J Int Soc Sports Nutr, 2026; PMID 42218768; Nutrients, 2026; PMID 41683255): 12-week trials of 200 mg/day with or without training in obese men, inflammatory and adipokine markers. Krishnakumar et al. (J Nutr Sci, 2022; PMID 36304817): single-dose pharmacokinetics in 15 volunteers. D Route 1: no human trial of the senolytic use has reported results.
Why Grade D Route 1 and not Grade C
Grade D Route 1 applies when no qualifying human randomized trial has tested this compound or intervention against the relevant endpoint. Absence confirmed: fisetin AND (randomized controlled trial[pt] OR randomized) AND humans[mesh] (PubMed, October 2026)
The first qualifying human RCT with a meaningful endpoint would move this to Grade C or higher, depending on what it shows.
What would move this grade
The first qualifying randomized controlled trial in humans, testing this intervention against a meaningful aging-relevant endpoint, would initiate grading. Depending on the result, it could land at any grade from A to D.