Erectile dysfunction (ED) is a common condition in men, particularly as they get older. Prescription medications, such as sildenafil (Viagra), can help stimulate blood flow back to the penis to help resolve ED. There are also many herbal supplements and natural remedies marketed as alternative treatments for ED.
One such product is derived from a summertime staple: watermelon. That’s because of an amino acid in watermelon called L-citrulline. L-citrulline is said to stimulate blood flow to the penis.
The research surrounding L-citrulline is not conclusive enough to prove that watermelon should be your go-to treatment method for managing symptoms of ED.
Watermelon contains high amounts of L-citrulline. This is a nonessential amino acid. Once it’s taken up by your nitric oxide system, it then promotes blood vessel dilation. As a result, your blood pressure decreases. Blood flow also improves.
L-citrulline may help stimulate enzymes called cGMPs. They play a direct role in blood flow. The thought is that more L-citrulline consumption could help improve ED. Unscientific accounts of L-citrulline are numerous on the internet, especially by supplement manufacturers.
In terms of scientific data, a few studies have looked at the role of L-citrulline in ED. One study published in Urology found that 24 men who took supplements over the course of a month noted improvements in mild ED symptoms. Another study looked at the effect of watermelon extract on male rats’ sexual activity and found an increase in activity. More long-term research needs to be conducted to explore the efficacy and overall safety of L-citrulline.