Besides well-known and very useful drugs against erectile dysfunction, One solution is the Ring ... The principle of the penis ring is simple. It grasps the base of the penis, and will therefore close a bit the veins that return blood from the penis to the body. This effect does not affect the arteries that are more powerfull and continue to pump the blood. Overall, much blood comes and less blood leaves the penis. It's simple and effective.
The advantages are obvious: no chemical in your body and it is cheaper then drugs.
The disadvantages also exist! It is difficult to hide from your partner, you need to put on erection occurs or at least at the start of intercourse. Usually this works if you have at least a little erection. And you must not wear for more than 30 minutes to allow blood flow. And never sleep with it!
One essential detail: finding the right size. If you have a ring too small, it hurts and it blocks the erection. If the ring is too is too large, it does not work.