Malegra 100 mg (which contains Sildenafil Citrate) is vasodilation caused by the drug. Here’s how and why it happens:  Why Flushing Occurs Malegra 100 mg is a PDE5 inhibitor, meaning it blocks the enzyme phosphodiesterase type 5 in blood vessels. This increases cGMP levels, which relaxes smooth muscles and widens blood vessels to improve blood flow to the penis — its intended effect. But PDE5 is present throughout the body, not just in the penis. When Sildenafil causes blood vessels elsewhere (like in the face, neck, or chest) to widen, it allows more blood into those areas. This produces redness and a warm sensation, Malegra 100 mg called flushing.   How It Feels Facial flushing typically feels like warmth and visible redness, especially on the face, neck, or upper chest. It’s usually temporary and mild, beginning within about 30–60 minutes of taking the dose and fading as the drug is metabolized.  Other Contributing Factors Higher doses (like 100 mg) are more likely to cause flushing than lower doses. Alcohol → Can enhance vasodilation and make flushing worse. Individual sensitivity → Some people’s blood vessels react more strongly than others.   Important Note Flushing itself is usually not harmful and doesn’t indicate allergy or damage, but if the redness is severe, persistent, or accompanied by other worrying symptoms (like chest pain or fainting), talk to a doctor.