Lung cancer is the second most common type of cancer, affecting more than two million people. The available treatments show limited effectiveness and undesirable side effects, thus, there is a huge demand for more effective treatments. The use of drugs already on the market has been proposed as a potential valuable approach. The aim of this study was to test the potential use of β-blockers, atenolol and metoprolol, and the peroxisome proliferator-activated receptor alpha (PPAR-α) receptor agonists, fenofibrate and gemfibrozil as coadjuvant in the treatment of this pathology. Thus, non-small cell lung cancer cell lines, A549 and H460, were exposed to different concentrations of β-blockers (500, 250, 125, 62.5, 31.25, 15.625 and 7.8125 µM) and PPAR-α receptor agonists (25, 12.5, 6.25, 3.125, 1.563, 0.781 and 0.391 µM). Metabolic viability was assessed by Resazurin and MTT viability assay at three different time points, 24, 48 and 72 hours. Atenolol and metoprolol did not demonstrate toxicity towards both cell lines in the tested concentrations and time-points. Gemfibrozil demonstrated limited toxicity towards both cell lines, with decreases of 20% of cellular viability at the maximum concentration tested at 24 hours and Fenofibrate showed toxicity only towards H460 with a calculated LC₅₀ of 20.6 µM. Therefore, Fenofibrate is a strong candidate to act as coadjuvant in the treatment of non-small cell lung cancer. Further studies are necessary to understand the impact of lipid regulators in the treatment of lung cancer.