Oxylipin status, before and after LC n-3 PUFA supplementation, has little relationship with skeletal muscle biology in older adults at risk of sarcopenia

•At baseline, certain n-9 and n-6 hydroxy‑PUFA derived oxylipins [i.e., 5- and 12-HETrE, and 5- 11- and 16-HETE] were negatively correlated with markers of skeletal muscle mass and strength in older adults at risk of sarcopenia.•LC n-3 PUFA shifted erythrocyte membrane FA composition and oxylipin profile, wherein higher concentrations of EPA and DHA derived oxylipins, and lower levels of n-9 and n-6 PUFA (especially ARA) derived oxylipins were present in plasma. However, LC n-3 PUFA supplementation did not impact skeletal muscle mass or strength.•Oxylipin changes with supplementation were closely correlated to their parent PUFA not only for EPA as previously described but also for most n-3 and n-6 PUFA.•LC n-3 PUFA-driven EPA and DHA derived oxylipin changes depended on EPA and DHA baseline status.