Comparison
Fisetin vs PT-141
Side-by-side of Fisetin and PT-141. 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.
PT-141
PT-141 peptide (bremelanotide, Vyleesi): MC4R agonist for libido and erectile dysfunction. 1.75 mg subcutaneous, 30 to 60 min onset, 2 to 4 h half-life.
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
PT-141
- •Cyclic 7-amino-acid synthetic peptide and melanocortin receptor agonist (MC4R-preferring)
- •FDA approved in 2019 as Vyleesi for hypoactive sexual desire disorder in pre-menopausal women
- •Acts centrally on hypothalamic sexual-desire circuits rather than peripherally on vasculature
- •On-demand dosing: subcutaneous 1.75 mg approximately 45 minutes before sexual activity
- •Common adverse effects: nausea (~40%), flushing, headache, injection-site reactions, hyperpigmentation
- •Off-label male ED use is documented but not FDA approved; mechanism is distinct from PDE5 inhibitors
Side-by-side
| Attribute | Fisetin | PT-141 |
|---|---|---|
| Category | supplement | peptide |
| Also known as | 3,7,3',4'-tetrahydroxyflavone | Bremelanotide, Vyleesi |
| Half-life (hr) ↗ | 2 | 2.7 |
| Typical dose (mg) ↗ | 500 | 1.75 |
| Dosing frequency | pulsed 2 days/month (Mayo protocol) or daily continuous (empirical) | as needed (max once per 24 hours, max 8 per month) |
| Routes | oral | subcutaneous |
| Onset (hr) | 1 | 0.75 |
| Peak (hr) | 4 | 1.5 |
| Molecular weight | 286.24 | 1025.18 |
| Molecular formula | C15H10O6 | C50H68N14O10 |
| Mechanism | Senolytic via Bcl-2 family inhibition (Bcl-xL, Bcl-w); broad polyphenol with Nrf2 activation, mTOR inhibition at high concentrations, and antioxidant effects. | Synthetic agonist of melanocortin receptors with preference for MC4R, expressed in hypothalamic and limbic circuits regulating sexual motivation. Engages central pathways distinct from peripheral PDE5-mediated vasodilation. |
| Legal status | OTC dietary supplement | Prescription only as Vyleesi; FDA-approved 2019 for HSDD in pre-menopausal women. Compounded versions sold off-label for male sexual function are research-use-only grey market. |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement | Rx only (not a controlled substance) for the FDA-approved Vyleesi formulation |
| Pregnancy | Insufficient data | Not recommended; contraindicated during pregnancy per Vyleesi label |
| CAS | 528-48-3 | 189691-06-3 |
| PubChem CID | 5281614 | 9941379 |
| Wikidata | Q230614 | Q422059 |
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)
PT-141
Common side effects
- nausea (~40%)
- flushing
- headache
- injection-site reactions
- hyperpigmentation (focal, gums, face, breasts)
- transient blood pressure increase (~6 mmHg systolic)
Contraindications
- uncontrolled hypertension
- established cardiovascular disease
- pregnancy
- naltrexone co-administration (reduces opioid efficacy due to MC receptor crosstalk)
Interactions
- naltrexone (oral): bremelanotide reduces oral naltrexone exposure significantly; avoid co-administration(major)
- antihypertensives: transient BP rise after bremelanotide can offset BP control(moderate)
- PDE5 inhibitors (sildenafil, tadalafil): no documented adverse interaction; mechanisms are non-overlapping(minor)
Which Should You Take?
Fisetin comes out ahead for most readers on the criteria we weight: 2 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-B outcome catalogued. PT-141 is the right call when one of the conditionals below applies.
- → If your priority is healthspan extension, pick Fisetin.
- → If your priority is focus or working memory, pick Fisetin.
- → If your priority is sexual function, pick PT-141.
- → If your priority is libido, pick PT-141.
Edge case: If you want to avoid research-only / gray-market sourcing, Fisetin is the more accessible choice.
Default choice: Fisetin. Lower friction to source, and broader goal coverage. Reach for PT-141 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 PT-141?
Fisetin and PT-141 differ in category (supplement vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Fisetin or PT-141?
Fisetin half-life is 2 hours; PT-141 half-life is 2.7 hours.
Can you stack Fisetin with PT-141?
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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