This pilot study will evaluate the safety and tolerability of the natural health product, fisetin, in older adults with mild cognitive impairment or mild Alzheimer's disease dementia.

Inclusion Criteria:

• Mild cognitive impairment due to Alzheimer's disease OR mild Alzheimer Dementia
• Moca score of 11 or higher
• Stable psychotropics and cognitive enhancing medications

Exclusion Criteria:

• Known hypersensitivity or allergy to fisetin
• Presence of any medical condition, or abnormal routine blood test, that the investigator believes would put the subject at risk or would preclude the patient from completing all aspects of the trial
• Unstable medical disorders
• Ongoing treatment for active infection with antibiotics/antifungals
• Ongoing treatment for cancer
• Active alcohol or substance use disorder
• Recent active bleeding
• Patients taking oral anticoagulants, anti-cancer, anti-seizure medications, or other medications that could have a significant interaction with fisetin
• Use within the last month of other senolytic supplements, antioxidant supplements, natural health products
• Other neurologic or neurodegenerative conditions impacting cognition
• Active Major Depressive Episode, active suicidal thoughts or psychosis
• Any thing that would preclude the ability to undergo an MRI scan