A combination of yohimbine and L-arginine is shown to significantly improve erectile function in people with ED. L-arginine is an amino acid that helps expand blood vessels. It’s regarded as safe and effective for ED but can cause side effects like nausea, diarrhea, and stomach cramps. Avoid taking L-arginine with Viagra, nitrates, or any high blood pressure medications.
Most importantly, herbal supplements are not well regulated in the United States. Studies have shown that 40-50% of herbal supplements do not even contain the supposed main ingredient, and many contain substances that are not listed which may have dangerous side effects2. Another study found that over two thirds of the products tested had substituted other plant species for the plants listed on the label, and a third of products also contained other fillers or contaminants3. A study by the New York State Attorney General of herbal products sold at GNC, Target, Walgreens, and Walmart found that four out of every five products didn’t contain the ingredient they claimed! Fourteen US states and territories have petitioned Congress to regulate the herbal supplements industry.
Korean red ginseng, also known as Asian ginseng or Chinese ginseng, is believed to be a highly effective natural remedy for treating ED. It is a traditional Asian remedy for sexual dysfunction and is widely used in the United States. Studies have shown that red ginseng can have significant therapeutic effects on penile rigidity and girth, libido, and patient satisfaction. It also has a reassuring safety profile, making it one of the most popular and proven natural remedy for ED.12
Another natural treatment for erectile dysfunction to consider would be vitamin E. This is a vitamin that has been linked to chronic diseases in the past due to the antioxidant effects of this vitamin. Considering ED could be a manifestation of another chronic condition, it makes sense that vitamin E may have a role in reducing the symptoms of the disease. As a person ages, it is natural for the body to undergo more oxidative stress and damage as cells do not function as well as they once did. Rats who were given supplemental vitamin E were found to have reduced levels of oxidative damage to their tissues and had levels of NO and other factors that help induce an erection more similar to younger rats compared to rats without vitamin E supplementation. If patients incorporate vitamin E into their vitamins and dietary supplements for ED, their ED should improve. 
For obvious reasons, ED can be a sensitive subject, one that until relatively recently men were more likely to try to hide than to deal with. Fortunately, a deeper understanding of the variety of causes of erectile dysfunction has led to medications, therapies, and other treatments that can be more individualized and more likely to be effective—and more open discussion about addressing the concern.
While the rationale behind why it would work is airtight, the research on arginine’s actual effect on erectile dysfunction is slim, points out Charles Walker, M.D., assistant professor of urology and cofounder of the Cardiovascular and Sexual Health clinic at Yale University. But given its solid safety profile, minimal side effects, and potential benefit on heart disease, it’s worth a try, he adds, especially when taken in conjunction with other herbs on this list, which studies have shown can be more effective.
DHEA. DHEA, or dehydroepiandrosterone, is a natural hormone that the body uses to make the male hormone testosterone. DHEA and testosterone decrease with age, just as ED increases with age, so it seems that taking DHEA might protect against ED. But Harris says that "it is unlikely that taking DHEA would raise your testosterone enough to make much difference." DHEA should not be used by people with liver problems; it also has many side effects.
Experts don't yet know whether the vitamin folic acid (also known as folate) is an effective natural treatment for erectile dysfunction. Research has shown that for some men, taking sildenafil (Viagra) together with folic acid and vitamin B6 seemed to help with erectile dysfunction more than taking medicine alone. Some experts contend that folic acid improves the function of the blood vessels involved in erections. But scientists say they need more studies to know if folic acid helps erectile dysfunction, either alone or in combination with other treatments.
A study published in May 2014 in The Journal of Sexual Medicine found that some men can reverse erectile dysfunction with healthy lifestyle changes, such as exercise, weight loss, a varied diet, and good sleep. The Australian researchers also showed that even if erectile dysfunction medication is required, it's likely to be more effective if you implement these healthy lifestyle changes.