Tazzle 20 FM is a medication that contains the active ingredient tadalafil, which is commonly used to treat erectile dysfunction (ED) in men. Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor that works by improving blood flow to the penis, allowing men to achieve and maintain erections when sexually aroused. Tazzle 20 FM is prescribed to men who have difficulty achieving or maintaining an erection sufficient for sexual intercourse, a condition known as erectile dysfunction (ED).