L-arginine: Some evidence suggests high doses of L-arginine improve erectile dysfunction by helping blood vessels to open wider, which improves blood flow to the penis. Side effects are generally considered mild but may include cramps, diarrhea, and nausea. L-arginine should not be taken with Viagra, a prescription drug that treats ED.
Propionyl-L-carnitine: Some studies show that propionyl-L-carnitine, when combined with Viagra, could improve erectile function better than when taking Viagra alone. Propionyl-L-carnitine is generally considered safe when used under supervision of a doctor.
Dehydroepiandrosterone (DHEA): There is some evidence that suggests that DHEA increases libido in women and has a positive effect on men with ED. DHEA appears to be safe at low doses, however, it may cause acne in some cases.
Ginkgo: Ginkgo may increase blood flow to the penis, which could improve sexual desire and ED. However, this supplement might increase the risk of bleeding. People who are taking blood thinners or who have a bleeding disorder should speak to their doctor before taking gingko.
Ginseng: There are several types of ginseng available. Many of them have been shown to have a positive effect on ED. Some forms of ginseng may have negative side effects including insomnia.
Yohimbine: The main component of an African tree bark, yohimbine is probably one of the most problematic of all natural remedies for ED. Some research suggests that yohimbine can improve a type of sexual dysfunction that is linked with a drug used to treat depression. However, studies have linked yohimbine to a number of side effects, which can include anxiety, increased blood pressure, and a fast, irregular heartbeat. Like all natural remedies, yohimbine should only be used after advice and under supervision from a doctor.