First up is L-Arginine. L-Arginine is one of the 20 common amino acids in humans. It can stimulate human growth hormone, cell division, and wound healing. It also has an important role in the immune system. Sounds nice right, even if does not make your penis bigger. But more then enough L-Arginine can be ingested through common foods such as oatmeal and dairy products.
Zinc Gluconate is often used as a zinc supplement. Zinc can help to reduce colds. As far as function down below zinc is essential for prostate health. Many males actually do not get enough zinc in their diet, but zinc supplements are much cheaper and more effective than penis pills.
Crataegus is a plant that is used to strengthen the heart, possibly important for those who want to have sex and have a weak heart. But it is also used a sedative. I don't know about you but I would like to stay awake through sex, but thats just me.
Muira Puama is a plant clinically proven to remedy sexual ineptitude. It is also thought to induce anxiety and increase stress, which is not so good.
My suggestion is to pass on penis pills and take a daily supplemental vitamin. You will not only get better results for overall health, but also skip on all the dangerous ingredients added to penis pills both intentionally and unintentionally. If you want to know about some of the less common ingredients link here.