Eat watermelon. It's not an herb, but it has properties that might help increase the size and duration of erections in a similar way arginine. Watermelon contains an amino acid called citrulline, which gets converted into arginine and leads to the dilation of blood vessels. The fact that watermelon contains citrulline is a relatively new finding, so no studies have been conducted to find out how well it really works or how much watermelon you'd have to eat to see the benefits. However, since watermelon is considered a superfood when it comes to men's health, you can't go wrong by eating plenty of it while it's in season.
First of all, we have to define what small really means and what statistics apart from any personal impressions and taste actually say: The flaccid size is irrelevant, some men have a rather small penis growing to enormous size when erect, on the other hand there are men with a rather impressive flaccid penis that just erects itself when aroused and doesn’t grow much in girth or length. Flaccid and erect size don’t correlate.
Many manufacturers market the products as dietary supplements because the products contain natural ingredients, including vitamins and minerals. When shopping for male enhancement products, read the label carefully. You might find that the product contains the same ingredients as those found in a multivitamin. You should also look at what the product does because not all supplements promise the same thing. Some shoppers want a male enhancement supplement that increases stamina, but some men want a product that only contains natural ingredients.