Megalis 20 mg contains tadalafil, a PDE5 inhibitor mainly prescribed for erectile dysfunction (ED). It works by relaxing smooth muscle and dilating blood vessels to improve blood flow in specific tissues, especially the penis. Tadalafil’s action is vascular, not a direct metabolic or performance‑enhancing effect like caffeine or creatine. Tadalafil does not directly increase energy levels, stamina, or muscle strength, nor does it act as a stimulant for workouts. Clinical pharmacology shows it doesn’t impact the central nervous system or metabolic pathways that produce cellular energy — it’s not a pre‑workout agent.