A plant pigment sold as a supplement on the strength of one mouse survival finding that the largest independent animal aging program did not reproduce. Human data are small and short: inflammation, blood sugar and body weight improved, mostly in people with illness or excess weight. Cheap, apparently well tolerated, unproven in people — a bet on a mechanism. (Full Review)

Protocol

Intermittent high-dose schedule

20 mg/kg daily for 2 days, monthly

Mayo Clinic protocol used in the frailty and COVID-19 trials; roughly 1,400 mg per day for a 70 kg adult

Continuous low-dose schedule

100 mg daily for seven weeks

Copenhagen group's trial in adults over 50, targeting chronic inflammation rather than senescent-cell clearance

Formulation matters more than dose

192 mg hydrogel = 27× the exposure of 1,000 mg powder

Label milligrams are close to meaningless across products; practice defaults to a morning dose with the day's largest fat-containing meal

Time to effect

Inflammatory markers

7–12 weeks

Moved over 7 to 12 weeks in the trials that measured them

Metabolic markers

12 weeks

Fasting glucose, insulin, insulin resistance and body weight over 12 weeks

Felt effects

Not expected

Nothing subjective has been shown to change on any timescale

Benefits

Medium: Lower systemic inflammation; improved glucose control and insulin sensitivity; reduced body weight; extended thrombolysis window in acute ischemic stroke

Low: Improved blood lipids alongside exercise

Speculative: Reduction in biological-age scores; senescent-cell clearance and lifespan extension; vascular and endothelial function; physical function and frailty; bone and cartilage preservation; neuroprotection and memory; anticancer activity; kidney protection; cardiac and hepatic protection from reperfusion injury

Contraindications

Pregnancy and lactation

Known urushiol-family allergy (poison ivy, oak, sumac, mango skin, cashew shell) where the product is a lacquer-tree extract

Active bleeding disorders, or platelet count below 100 ×10⁹/L

Scheduled surgery within 14 days

Severe hepatic impairment (Child-Pugh Class C)

Advanced kidney disease (eGFR below 30 mL/min/1.73 m²) outside a supervised trial

People under 18

Active cancer treatment, unless the treating oncologist has approved it

Key Interactions

CYP2C8 substrates (paclitaxel, repaglinide, montelukast, rosiglitazone, amiodarone)

Anticoagulants and antiplatelets (warfarin, apixaban, clopidogrel, aspirin)

Antihypertensives (amlodipine, lisinopril, losartan, hydrochlorothiazide)

Glucose-lowering agents (metformin, glipizide, insulin)

Over-the-counter analgesics (ibuprofen, naproxen, low-dose aspirin)

Over-the-counter acid blockers and antacids (omeprazole, calcium carbonate)

Supplement interactions (quercetin, curcumin, resveratrol, green tea catechins)

Supplements with additive antiplatelet effect (fish oil, ginkgo, garlic, nattokinase, high-dose vitamin E)

Supplements with additive blood-pressure lowering (beetroot nitrate, magnesium, hibiscus, potassium)

Other senolytic protocols (dasatinib plus quercetin)

Cytotoxic chemotherapy and radiotherapy

Risk & Side Effects

Low: Additive blood-pressure lowering; allergic skin reactions from lacquer-tree material; transient non-serious adverse events

Speculative: Worsening of biological-age scores; increased bleeding risk with anticoagulants and antiplatelet agents; drug interactions through CYP2C8 inhibition; genotoxicity at high concentrations; altered response to concurrent cancer treatment

Monitoring

Marker	Target	Why
hs-CRP	< 1.0 mg/L	Primary inflammation marker moved in the human trials
Interleukin-6	< 2.0 pg/mL	Second inflammatory signal that fell with fisetin
suPAR	< 3.5 ng/mL	Primary endpoint of the ongoing low-dose fisetin trial
Fasting insulin	2–6 µIU/mL	Insulin resistance improved in both obesity trials
HOMA-IR	< 1.5	The composite index that actually moved
Fasting glucose	75–86 mg/dL	Fell in every active trial arm
HbA1c	4.8–5.3%	Confirms that fasting changes reflect real glycaemic change
LDL cholesterol	< 80 mg/dL	Lipids shifted in the combined training arm
ALT	10–26 U/L (women), 10–30 U/L (men)	Detects liver effects no trial was long enough to exclude
eGFR	> 90 mL/min/1.73 m²	Kidney clearance safety check
Platelet count	175–250 ×10⁹/L	Baseline for the theoretical antiplatelet effect
Seated blood pressure	110–120 / 70–80 mmHg	Catches additive vasodilation
Epigenetic age	No established target — track the change from the individual's own baseline	The outcome the only human aging pilot measured

Cadence: Baseline panel before the first dose; on an intermittent monthly schedule, repeat the inflammation and metabolic markers at 8–12 weeks and then every 6 months; liver and kidney panels once at 3 months and annually thereafter; home blood pressure daily through the first two cycles for anyone already on antihypertensive medication

Qualitative Assessment

Physical function — grip strength, chair-stand time, or usual walking pace
Joint comfort and morning stiffness
Energy and daytime fatigue
Sleep quality and duration
Skin bruising or gum bleeding
Any itching or rash within 48 hours of a dose

Fisetin for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment