I was reading about ED, as in the last few days have had an issue, could be mental, saw doctors, having tests etc, but natural substances that have similar effect to viagra are L Arginine and L Citrulline with Beetroot Extract - Nitric Oxide Supplement, these relax the tension and allow for an erection. Ordered some and after about 4 days I am back to full mast, this is without any side effects, for me at least, and just a supplement .
Got nothing to loose, but do not take if you consider taking viagra or similar as will drop your blood pressure to a dangerous level.