ED can be caused by a handful of things, but one thing’s for sure: You need a healthy supply of the neurotransmitter nitric oxide (NO) to get and maintain an erection. NO is produced in nerve tissue and helps jolt your Johnson by relaxing the smooth muscle so blood can fill the penis. After the initial release of NO, your body releases a cascade of chemicals—including more of the neurotransmitter—to help keep you hard and happy, according to a study in the Proceedings of the National Academy of Sciences.
Tribulus Terrestris is the fruit of the Zygophyllaceae plant and it grows primarily in North China. It is a well-known aphrodisiac with records that trace back to ancient times. There are plenty of animal experiments that verify the effectiveness of Tribulus for improving erectile function. These effects are mostly due to its androgen enhancing ability, namely increasing testosterone levels. Though testosterone doesn’t directly cause an erection, it does play a role. Erection is made possible by many factors, but mostly it's through receptors on cells lining our arteries that stimulate a chain reaction that relaxes the blood vessels that go to the penis, allowing blood flow to get in. Low testosterone is often associated with overall poor metabolic and cardiovascular health. When the test is low, estrogen is usually high, leading to oxidative stress and calcification of the arteries, including the penis, restricting blood flow to the penis. So, improving testosterone levels, and improving overall metabolic function, while reducing oxidative stress is a good plan for improving overall sexual function and erection.
However, you might actually be better off going one step back in the chain reaction and taking an L-citrulline supplement. While your body converts L-arginine to nitric oxide, it also metabolizes it too fast when the amino acid is taken in an oral supplement, according to a 2011 study from the University of Foggia in Italy. L-citrulline, which the body converts to L-arginine, is actually a better option to follow the same metabolic pathway and serve as a treatment for ED, the same study found.
The Claim: If you squint and have an excellent imagination, mature ginseng roots vaguely resemble a human body. That ties into folk ideas for finding medicines–in this case, the idea that a plant that looks like a person must contain materials that help sick people. Ginseng was traditionally used as a tonic to treat erectile dysfunction and low sexual drive in men (as well as many other complaints).
These medications don’t work for everyone but they are easy to use and work for around 60% of people who try them. They work by making it easier to get an erection by reducing the effect of (inhibiting) the chemical PDE-5. This chemical is used in the body to make sure there isn’t too much blood in the penis during an erection, but if you have erectile dysfunction then this chemical ends up over-compensating.
Many stores sell herbal supplements and health foods that claim to have sexual potency and fewer side effects. They’re also often cheaper than prescribed medications. But these options have little scientific research to back up the claims, and there’s no uniform method on testing their effectiveness. Most results from human trials rely on self-evaluation, which can be subjective and difficult to interpret.