Preliminary research suggests that dietary phospholipids could positively impact human neuromuscular function and physiology (Ota et al, 2015; Soga et al, 2015), with preliminary studies indicating that short-term supplementation (≤ 2 weeks) could increase muscle strength and power (Bellar et al, 2015; Marcus et al, 2017). However, evidence from current short-term studies is inconclusive. Furthermore, there are contrasting phospholipid profiles between dairy-based and plant-based phospholipids (Zhu et al, 2024), which could influence the effect of dietary phospholipids on the neuromuscular system. Therefore, the aim was to document any changes in neuromuscular function and physiology after 2 weeks of dairy- or plant-based phospholipid supplementation in healthy middle-aged adults. Thirty-six healthy, middle-aged adults were randomised to consume either bioactive whey protein concentrate (BWP, n = 17), whey protein and phospholipids, or bioactive pea protein concentrate (BPP, n = 19), pea protein and phospholipids, daily (~ 40 g per serving) for 2 weeks. Measurements at pre and post included: maximal and explosive isometric force of the dorsiflexors (DF) and plantar flexors (PF), supramaximally evoked twitch contractions of the DF and PF, DF force-frequency relationship and octet contractions, and power during a maximal countermovement jump. Throughout isometric measurements, surface electromyography (EMG) signals of the tibialis anterior, soleus, and gastrocnemius (medialis and lateralis) were recorded. In addition, tibialis anterior intramuscular EMG signals were recorded during submaximal DF contractions (10% and 25% of maximal DF force) and decomposed to extract motor unit characteristics. The study was approved by Loughborough University Ethical Advisory Committee (2023-15740-15863) and was conducted in accordance with the Declaration of Helsinki, except for registration in a database. There were no within-group changes in maximal strength of the DF (BWP, 2%, p = 0.7209; BPP, 2%, p = 0.8928) or PF (BWP, 3%, p = 0.5661; BPP, 4%, p = 0.5437), nor normalised (%Mmax) agonist or antagonist EMG during both the DF and PF maximal voluntary contractions (p ≥ 0.5144). Explosive DF and PF force (at 50, 100, 150 ms), along with normalised agonist and antagonist EMG (0-50, 0-100, 0-150ms) of both groups were unchanged pre to post (p ≥ 0.1990). No within-group changes were found for peak twitch force of the DF (BWP, -1%, p = 0.9882;  or BPP, 1%, p = 0.3112) or PF (BWP, 1%, 0.9976; BPP, -3%, 0.0874). Octet force (25, 50, 75 ms; peak) did not change from pre to post for either group (p ≥ 0.5968). Normalised (%100Hz force) peak force at a series of stimulation frequencies (1-50 Hz) remained unchanged from pre to post for both groups (p ≥ 0.2102). At both contraction intensities (10 and 25%), there were no within-group changes in motor unit characteristics (p ≥ 0.4890) or neuromuscular junction transmission instability (p ≥ 0.1887). Peak power during the countermovement jump did not change for either group from pre to post (BWP, 0%, p = 0.9977; BPP, 0%, p = 0.9333). These findings suggest that short-term supplementation of dietary phospholipids, either dairy- or plant-based, does not influence neuromuscular function or physiology of healthy middle-aged adults.