Comparison
Fisetin vs N-Acetyl Cysteine
Side-by-side of Fisetin and N-Acetyl Cysteine. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Fisetin
Fisetin is a flavonoid found in strawberries with senolytic activity in mouse models. Hickson 2019 confirmed senescent-cell clearance in human adipose tissue.
N-Acetyl Cysteine
NAC supplement benefits cover glutathione synthesis, liver and antioxidant support, and hangover recovery. Evidence strongest at 1200-2400 mg/day.
Effects at a glance
Fisetin
- •Flavonoid found in strawberries; most potent natural senolytic in screening assays (Yousefzadeh 2018)
- •Hickson 2019 confirmed reduced senescent-cell burden in human adipose tissue at 20 mg/kg pulsed for 2 days
- •Pulsed Mayo protocol (20 mg/kg/day x 2 days monthly) is the only dose with human biomarker evidence
- •Daily low-dose (100-500 mg) is mechanistically weaker but commonly used
- •Low oral bioavailability; with-fat dosing modestly improves absorption
- •Active cancer is a relative contraindication pending clearer polyphenol-treatment data
N-Acetyl Cysteine
- •Replenishes intracellular glutathione by supplying cysteine, the rate-limiting amino acid for synthesis
- •First-line antidote for acetaminophen toxicity, restoring hepatic glutathione before fulminant injury occurs
- •Reduces sputum viscosity in chronic bronchitis and COPD at 600 to 1200 mg/day over months
- •Modest symptom reductions in OCD and trichotillomania at 1200 to 2400 mg/day across small RCTs
- •Mixed evidence for psychiatric adjunct use in bipolar depression and schizophrenia negative symptoms
- •Inhaled forms can trigger bronchospasm in active asthma; oral use is the standard biohacker route
Side-by-side
| Attribute | Fisetin | N-Acetyl Cysteine |
|---|---|---|
| Category | supplement | supplement |
| Also known as | 3,7,3',4'-tetrahydroxyflavone | NAC |
| Half-life (hr) ↗ | 2 | 5.6 |
| Typical dose (mg) ↗ | 500 | 1200 |
| Dosing frequency | pulsed 2 days/month (Mayo protocol) or daily continuous (empirical) | 1 to 3 times daily, split dosing preferred |
| Routes | oral | oral, iv |
| Onset (hr) | 1 | 1 |
| Peak (hr) | 4 | 2 |
| Molecular weight | 286.24 | 163.19 |
| Molecular formula | C15H10O6 | C5H9NO3S |
| Mechanism | Senolytic via Bcl-2 family inhibition (Bcl-xL, Bcl-w); broad polyphenol with Nrf2 activation, mTOR inhibition at high concentrations, and antioxidant effects. | Deacetylated to cysteine, the rate-limiting precursor for glutathione synthesis; also directly scavenges reactive oxygen species and modulates glutamate signaling. |
| Legal status | OTC dietary supplement | OTC in most jurisdictions; restricted periods in US history (FDA reclassified 2022) |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement | OTC supplement (US, post-2022); Rx indications also exist (acetaminophen overdose, mucolytic) |
| Pregnancy | Insufficient data | Used clinically in pregnancy for specific indications; consult clinician |
| CAS | 528-48-3 | 616-91-1 |
| PubChem CID | 5281614 | 12035 |
| Wikidata | Q230614 | Q413299 |
Safety profile
Fisetin
Common side effects
- mild GI upset
- headache (rare)
Contraindications
- active cancer (theoretical, polyphenol interactions)
- pregnancy and lactation (insufficient data)
- concurrent CYP3A4-sensitive medications
Interactions
- statins (CYP3A4 substrates): theoretical reduction in statin clearance at high fisetin doses(minor)
- warfarin: theoretical CYP-mediated interaction; monitor INR if combining(moderate)
- other senolytics (rapamycin, dasatinib + quercetin): additive senolytic effect; pairing is investigational(minor)
N-Acetyl Cysteine
Common side effects
- sulfur-like taste or odor
- nausea
- flatulence
- diarrhea
Contraindications
- active asthma attack (inhaled form can trigger bronchospasm)
- known NAC hypersensitivity
Interactions
- nitroglycerin: potentiates vasodilation, risk of hypotension and headache(moderate)
- activated charcoal: reduces NAC absorption when used for acetaminophen overdose(moderate)
- anticoagulants: theoretical additive antiplatelet effect at high doses(minor)
Which Should You Take?
N-Acetyl Cysteine comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC, oral dosing, with a Tier-A outcome catalogued. Fisetin is the right call when one of the conditionals below applies.
- → If your priority is focus or working memory, pick Fisetin.
- → If your priority is post-training recovery, pick N-Acetyl Cysteine.
- → If your priority is liver function, pick N-Acetyl Cysteine.
Default choice: N-Acetyl Cysteine. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Fisetin only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Fisetin and N-Acetyl Cysteine?
Fisetin and N-Acetyl Cysteine differ in category (supplement vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Fisetin or N-Acetyl Cysteine?
Fisetin half-life is 2 hours; N-Acetyl Cysteine half-life is 5.6 hours.
Can you stack Fisetin with N-Acetyl Cysteine?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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