Do you know the ingredients in the virility diet?

What to eat to get harder erections. (Little blue pill not required.)
© Details // © Details

Watermelon

The summer fruit is high in citrulline, which -- like that little blue pill -- stimulates nitric-oxide production and increases blood flow to the penis, strengthening erections.

1 of 16 Watermelon (© CN Digital Studio)

Dark Chocolate

This treat is loaded with flavonoids that dilate your arteries. Eat about 1.6 ounces of dark chocolate (about the size of a regular Hershey's bar) daily -- that's the amount researchers at the University of California found improved blood-vessel dilation by more than 10 percent.

2 of 16 Dark Chocolate (© CN Digital Studio)

Cherries

Studies show that flavonoids in red, blue, and purple berries cleanse free radicals from arteries, relaxing them and improving blood flow.

3 of 16 Cherries (© Dina Telhami/Getty Images)

Oysters

Yes, they really are aphrodisiacs. Raw oysters are the richest dietary source of zinc, which not only improves blood flow but also fuels testosterone production. When testosterone levels drop, so do your performance and your libido, Lamm says. Wild eastern oysters have the most zinc, followed by eastern farmed and wild Pacific.

4 of 16 Oysters (© Jamie Grill/Getty Images)

Grass-fed butter

Recent studies have shown that people with the highest intakes of the vitamin K2, found in grass-fed beef and dairy products like butter, cut their risk of coronary heart disease in half. And what's good for your ticker is always good for your erections.

5 of 16 Grass-fed butter (© CN Digital Studio)

Bananas

Don't giggle: Bananas are high in potassium, which relaxes blood-vessel walls, allowing for better blood flow throughout the body. Plus it offsets a high-sodium diet, keeping your blood pressure in check, according to a study in the journal Hypertension. Narrow blood vessels lead to low blood flow, which leads to . . . well, not much.

6 of 16 Bananas (© CN Digital Studio)

Garlic

This allium vegetable boosts blood flow to the penis by increasing nitric-oxide production and relaxing blood vessels.

7 of 16 Garlic (© CN Digital Studio)

Walnuts

The amino acid L-arginine, found abundantly in walnuts, is one of the building blocks of nitric oxide. Translation: A diet that includes these nuts with the rock-hard shell makes for consistent, rock-hard erections. According to a panel conducted by the European Food Safety Authority, you should eat about ¼ cup a day.

8 of 16 Walnuts (© CN Digital Studio)

Ginger

By scrubbing blood vessels of free radicals and decreasing inflammation, ginger relaxes arteries and improves blood flow. According to a study in the International Journal of Cardiology, about 1 teaspoon a few times a week is all you need to reap ginger's cardiovascular rewards.

9 of 16 Ginger (© CN Digital Studio)

Nutmeg

A study of natural aphrodisiacs in the BMC Complementary and Alternative Medicine journal found that nutmeg increases libido and erectile performance. Nutmeg also contains myristic acid, which has been shown to stimulate production of the all-important nitric oxide, the key to a healthy erection.

10 of 16 Nutmeg (© CN Digital Studio)