Enter: For Hims. Prolonged erections can be dangerous. Do not mix the liquid with other medications or add anything to flavor the medication. Sildenafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow easily. If you are taking sildenafil to treat PAH, you will probably take sildenafil three times a day with or without food. Sexual arousal triggers a response in your body that then triggers nitric oxide production, which relaxes the blood vessels and smooth muscle in the penis. Some people may also have ringing in their ears tinnitus or dizziness.AdShop Forhims Online for Great Prices at Store Sale & Clearance. Up To 60% Off Forhims Official Sale. Side Effects. Dizziness, headache, flushing, or stomach upset may occur. Vision changes such as increased sensitivity to light, blurred vision, or trouble telling blue and green colors apart may. As a brand-name erectile dysfunction medication, Viagra® is significantly more expensive than the generic version of the medication, sildenafil citrate. Through hims, Viagra® is $ per use. At other pharmacies, prices can range from tens to hundreds of dollars. Learn more about Viagra® pill prices here.