Eating watermelon rind is perfectly safe and actually delivers more of certain nutrients than the red flesh you’re used to. The white and pale green part between the skin and the pink fruit is edible, rich in fiber and an amino acid called citrulline that supports blood flow and heart health. Most people throw the rind away, but it’s been eaten for centuries in cultures around the world.
What’s Actually in the Rind
Watermelon rind contains 3 to 5.5% fiber by fresh weight, significantly more than the watery flesh. It also contains citrulline at concentrations of 0.06 to 0.5%, which matters because citrulline is the compound behind many of watermelon’s health claims. The rind has modest amounts of vitamin C (around 5 to 8 mg per 100 grams on a dry weight basis) and vitamin B6 as well.
The rind is low in calories and mostly water, similar to the flesh. Think of it as a mildly flavored, crunchy vegetable rather than a fruit. The taste is neutral to slightly sweet, closer to cucumber than watermelon.
How Citrulline Benefits Your Body
Citrulline is the standout compound in watermelon rind. Your kidneys convert it into arginine, which your blood vessel walls then use to produce nitric oxide. Nitric oxide signals the smooth muscle around your arteries to relax, widening them and lowering blood pressure. This chain reaction is why watermelon and citrulline supplements show up in research on cardiovascular health and arterial stiffness.
A meta-analysis published in Frontiers in Nutrition examined randomized controlled trials of citrulline supplementation and watermelon intake in middle-aged and older adults. The mechanism is straightforward: more citrulline means more arginine, which means more nitric oxide, which means better blood vessel flexibility. For people with mildly elevated blood pressure or stiff arteries, this is a meaningful pathway.
Citrulline has also been linked to faster exercise recovery. Research suggests it can reduce muscle soreness 24 hours after intense activity and help bring heart rate down more quickly post-exercise. You won’t get the same concentrated dose from eating rind that you’d get from a supplement, but it’s a legitimate dietary source.
Digestive Effects
If you’re worried about stomach problems, the evidence is reassuring. A study that had participants drink blended watermelon juice with the rind included found no constipation, no digestive discomfort, and no significant changes in bowel movements compared to a control. The rind did, however, improve feelings of fullness and led to better blood sugar responses after eating. So the fiber works in your favor without causing the bloating or gas you might expect from a new high-fiber food.
That said, if you eat a large amount of rind for the first time, your gut may need time to adjust, the same way it would with any sudden jump in fiber intake. Starting with a few pieces and working up from there is a reasonable approach.
How to Clean It Properly
Since you’re eating the outer portion of the fruit, cleaning matters more than usual. The National Pesticide Information Center recommends scrubbing firm produce like melons with a clean brush under running water. This reduces dirt, bacteria, and pesticide residues on the surface. Don’t use soap, detergent, or commercial produce washes. The FDA has found these aren’t more effective than water alone.
No washing method removes 100% of pesticide residues, but scrubbing under running water is the most effective approach for firm-skinned produce. If pesticide exposure is a concern, choosing organic watermelons is an option, though conventional watermelons that are properly washed are considered safe.
Ways to Make It Taste Good
Raw watermelon rind has the texture of a firm cucumber and very little flavor on its own. That blank canvas is actually an advantage in the kitchen. Here are the most common ways people prepare it:
- Pickled: The most traditional method, common in the American South and parts of Asia. Soak rind pieces in a brine of vinegar, sugar, and spices like cloves and cinnamon. The result is tangy, sweet, and crunchy.
- Stir-fried: Popular in Chinese cooking. Cut the rind into thin strips, remove the hard green outer skin, and stir-fry with garlic, soy sauce, and chili. It cooks like zucchini.
- Blended into smoothies: Cube the white rind and toss it in a blender with fruit juice or other smoothie ingredients. You won’t taste it, but you’ll get the fiber and citrulline.
- Candied: The Culinary Institute of America teaches a method where you soak rind strips in salt water overnight, simmer them in a vinegar-sugar-spice syrup until translucent, then coat them in sugar. The result works as a garnish for cocktails, desserts, or dipped in chocolate.
- Slaw or salad: Shred the rind on a box grater and dress it like coleslaw. It pairs well with lime, cilantro, and sesame oil.
For all these methods, you’ll want to trim off the hard green outer skin first. A vegetable peeler works, or you can slice it off with a knife. The part you’re eating is the white to pale green layer underneath.
Who Should Be Cautious
Watermelon rind is safe for most people, but there are a few edge cases. Because citrulline affects nitric oxide production and blood vessel dilation, people taking blood pressure medications should be aware that large quantities could amplify those effects. In practice, the amount of citrulline in a few pieces of rind is modest, but it’s worth knowing the mechanism if you’re actively managing blood pressure with medication.
People with kidney disease should also be mindful. Since the kidneys handle the conversion of citrulline to arginine, impaired kidney function could change how your body processes this compound. For anyone with healthy kidneys and no blood pressure medications, eating watermelon rind carries no known risks beyond the minor digestive adjustment that comes with any new fiber source.