Ongoing Lung Decline With Age Intensified Response

Inclusion Criteria: * Adults aged 60 years and older who are physically capable of participating in study procedures; * Willing to be randomized to fisetin or placebo; weight stable within the previous 2 months (\<5-pound change); * No blood donation within 2 months before screening; absence of unstable chronic disease; * Willing to maintain baseline activity level throughout the study; * Body mass index \<30 kg/m²; * Either a history of at least 10 pack-years of cigarette smoking or never-smoking status. Exclusion Criteria: * Electrocardiogram (ECG) abnormalities, including prolonged QTc. * Use of fisetin, other flavonoid supplements, or known senolytic compounds within 6 months prior to screening. * Resting systolic blood pressure \>160 mmHg or diastolic blood pressure \>110 mmHg. * Known allergy or hypersensitivity to fisetin or any component of the study product. * Active malignancy, except non-melanoma skin cancer. * Clinically significant hepatic, renal, cardiovascular, endocrine, immunologic, metabolic, or other uncontrolled medical conditions that, in the opinion of the investigator, would interfere with study participation or interpretation of results. * Clinically significant laboratory abnormalities, including severe anemia, leukopenia, thrombocytopenia, uncontrolled diabetes, advanced kidney disease, significant liver dysfunction, or evidence of systemic inflammation. * Human immunodeficiency virus (HIV) infection, active hepatitis B or hepatitis C infection, o…