Penegra 50 mg, which contains sildenafil, is primarily used to treat erectile dysfunction (ED). However, sildenafil (the active ingredient in Penegra) has also been approved for other medical conditions:

1. Pulmonary Arterial Hypertension (PAH): Sildenafil is used to treat PAH, a condition characterized by high blood pressure in the lungs. It works by relaxing the blood vessels in the lungs, making it easier for the heart to pump blood through them. The brand name for sildenafil used to treat PAH is Revatio, which is typically available in lower doses (e.g., 20 mg).
   
2. Raynaud’s Phenomenon: Sildenafil may be used off-label to treat Raynaud’s phenomenon, a condition in which small blood vessels in the fingers and toes constrict in response to cold or stress, reducing blood flow. Sildenafil can help by improving blood flow through these vessels.
   

Though these are some of the key uses of sildenafil, it is most commonly prescribed for erectile dysfunction. If you're considering Penegra 50mg for a condition other than ED, it's important to discuss it with your healthcare provider to ensure it's appropriate for your situation.