Sarcopenia, the age-related loss of skeletal muscle mass, strength, and function, represents a major determinant of frailty and disability in older adults. Nutraceutical strategies targeting inflammation and oxidative stress have been proposed as adjunctive countermeasures. Olive mill wastewater (OMWW), a byproduct of olive oil production, is rich in hydroxytyrosol and other polyphenols with potent antioxidant and anti-inflammatory effects. Results from a 30-day, single-arm pilot trial to evaluate several biometric and anthropometric parameters, after assumption of the OMWW extract, OMWW-OL (Oliphenolia®), revealed a positive trends to ameliorate sarcopenia-related values in adults with metabolic syndrome, a population at elevated risk for muscle decline. Twenty-nine participants were enrolled, and 23 (15 men, 8 women) completed the study. Assessments included bioimpedance-derived indices of muscle mass, anthropometry, handgrip strength, calf circumference, hydration, and inflammatory/metabolic markers at baseline (T0), after supplementation (T1), and 30 days post-intervention (T2). OMWW-OL was well tolerated. Participants showed modest but consistent trends toward improved fat-free mass index (FFMI), appendicular skeletal muscle mass (ASMM), and handgrip strength at T1, with partial persistence at T2. Calf circumference increased steadily across the observation period. Among biochemical markers, oxidized LDL (oxLDL), a lipid peroxidation indicator linked to muscle catabolism, showed a small but progressive reduction from T0 to T2, consistent with the antioxidant profile of OMWW polyphenols, whereas CRP exhibited a transient rise at T1 before returning near baseline at T2.Although statistical significance was limited by small sample size and study design, the observed trends align with preclinical evidence that OMWW polyphenols mitigate oxidative stress, suppress pro-inflammatory cytokines, and promote muscle protein homeostasis. These exploratory findings justify larger randomized trials to evaluate OMWW as a nutraceutical strategy for sarcopenia prevention and management. Sarcopenia has been also associated with cancer, is higher in oncology patients with metabolic syndrome and worsens response to therapy. Cosmeceutical preparations using OMWW-OL also reveal protective properties for the skin. One of the major polyphenols in OMWW-Ol is hydroxytyrosol, and investigations are ongoing oh the role of the purified substance.