Tadalis SX 20 mg contains tadalafil, a medication that helps improve blood flow to the penis, particularly in men with erectile dysfunction (ED). The way it works is through its ability to inhibit the enzyme phosphodiesterase type 5 (PDE5). Here’s how Tadalis SX 20 mg helps with blood flow:

1. Inhibition of PDE5: Tadalafil works by blocking the action of PDE5, an enzyme that normally breaks down cyclic guanosine monophosphate (cGMP). cGMP is a molecule that helps relax the smooth muscle in blood vessels, which allows for increased blood flow. When PDE5 is inhibited, cGMP levels remain elevated, promoting relaxation of the smooth muscle in the blood vessels of the penis.
   
2. Increased Blood Flow to the Penis: As the smooth muscle relaxes, the blood vessels dilate, allowing more blood to flow into the penile tissue. This results in improved erectile function, making it easier to achieve and maintain an erection during sexual arousal.
   
3. Long Duration of Action: One of the advantages of tadalafil (in Tadalis SX 20 mg) is its long half-life, which means it can remain effective for up to 36 hours. This allows for greater spontaneity in sexual activity, as the medication stays active in the system for a longer period, supporting blood flow to the penis when needed.
   
4. No Effect Without Sexual Stimulation: It’s important to note that tadalafil, like other PDE5 inhibitors, only works when sexual arousal occurs. It doesn’t directly cause an erection but enhances the natural process of achieving one by improving blood flow when combined with sexual stimulation.
   

In summary, Tadalis SX 20 mg helps with blood flow to the penis by inhibiting PDE5, which increases the levels of cGMP. This results in the relaxation of blood vessels and enhanced blood flow, ultimately improving erectile function.