Perhaps the fruit’s most touted benefit when it comes to a man’s sex life is its effect on erectile dysfunction. Researchers credit the amino acid citrulline found in this tropical fruit for improving symptoms of ED. More specifically, your body converts citrulline into arginine which boosts blood flow to the penis. 

According to a 2013 study done on mice and published in The Journal of Sexual Medicine, citrulline water supplement was found to improve erectile function in subjects with arteriogenic erectile dysfunction (a condition where erections become a problem because of reduced blood supply to the penis). A 2014 study published in the Chiang Mai University Journal of Natural Sciences (also done on rats) found an increase in arousal and sexual play in subjects that consumed watermelon, another unexpected consequence of this fruit. 

An older 2011 study done on men with mild ED and published in the journal Urology found that half the subjects who consumed the citrulline supplement experienced improvements in erection levels (hardness). Men with arteriogenic erectile dysfunction have lower levels of either citrulline or arginine (an amino acid responsible for dilating your blood vessels and increasing blood flow to your nether regions), according to a 2017 study published in Andrology. Does this mean all men with any concern related to ED should be loading up on watermelon?