Fisetin Supplements UK 2026: Buying Guide

TL;DR: Most UK fisetin supplements contain 100–500 mg per capsule. Research protocols use far higher intermittent doses. Look for high purity (typically 98%+), a clear amount per serving, third-party testing and a UK-registered seller. Fisetin is promising but not proven senolytic in humans.

1. What Is Fisetin?

Fisetin is a flavonoid found in strawberries, apples and cucumbers. It is being studied as a senolytic — a compound that may help clear senescent cells. Read our full fisetin anti-aging evidence review for the research picture.

2. What Dose Is Used in Research?

The Mayo Clinic-style intermittent protocol uses roughly 20 mg/kg on two consecutive days per month. For a 70 kg adult, that is ~1,000–1,400 mg/day on dosing days. UK supplements are usually 100–500 mg/day, much lower and taken daily rather than intermittently. No human trial has proven daily low-dose fisetin is senolytic.

3. Buying Checklist

• Purity: 98% or higher is common for research-grade fisetin.
• Amount per serving: must state the actual fisetin content, not total capsule weight.
• Source: often extracted from Sophora japonica.
• Third-party testing: look for a certificate of analysis (COA).
• Seller: UK-registered company with returns policy and customer service.
• No illegal claims: avoid products claiming to treat or cure disease.

4. Common Forms

• Capsules: most common; convenient and easy to dose.
• Powder: cheaper per gram but harder to measure accurately.
• Liposomal / complexed: marketed for absorption; human bioavailability data are limited.

5. Safety and Interactions

• Generally well tolerated in short-term studies.
• May have antiplatelet effects; use caution with warfarin, apixaban, rivaroxaban, clopidogrel, aspirin.
• Stop before surgery due to bleeding risk.
• Avoid in pregnancy and breastfeeding.

6. References