When to Stop

• Pro-oxidant chemistry at very high doses. In vitro, fisetin + Cu2+ catalyzes DNA cleavage. Not demonstrated in vivo at human doses but a caveat for users contemplating mega-dosing (>4-5 g/day).
• Drug-interaction-mediated adverse events. Most plausible: warfarin INR rise (CYP2C9 inhibition — see Drug interactions), statin pharmacokinetic change (OATP inhibition), increased benzodiazepine effect (CYP3A4 inhibition). No published case reports but theoretical.
• Bleeding risk if combined with antiplatelet/anticoagulant. Theoretical, low-confidence; flagged in the supplement-drug AI-seeded interaction matrix.
• Allergic reaction. Standard supplement-allergy possibility; no specific fisetin syndrome documented.
• Theoretical wound-healing impairment. Senescent cells participate in acute wound healing; clearing them during active repair could (in theory) slow healing. No human evidence; mechanism-driven concern only.
• Pulse day 1-2: GI tolerance check. If significant nausea/diarrhea, reduce next pulse to 1,000 mg or skip.
• Post-injury / post-surgery (30-90 day window): Defer pulse — let acute repair complete before clearing senescent cells from healing tissue.
• First time using bioavailability-enhanced form (liposomal/Novusol): Effective exposure is higher; start with single 1,000 mg dose to check tolerance before going to full 1,500-2,000 mg × 2 days.
• Unknown. No human data beyond 12 months. The Mayo knee-OA trial reported 12+ months follow-up with no safety concerns at 3 cycles. The theoretical concern is whether routinely clearing senescent cells across decades has unintended consequences (immune-surveillance changes, wound-healing changes, age-paradox tumor-microenvironment effects).
• For young users (<35): This is the bigger concern because pulse-clearance would be applied to a population that isn't gaining a benefit — no upside to offset theoretical downside.