Most of us eat the banana without giving the soft, mushy peel a second thought. Here’s why that’s a mistake: “Bananas contain tryptophan, which boosts serotonin ‘the happiness hormone’ to help with mood regulation and nerve impulses,” says Popeck. A few creative ways to use the peel: First off, go ripe. “Riper peels are softer, thinner, and tastier,” says Popeck. Cook or boil for at least 10 minutes to soften. You can add to smoothies, stir-fries, or soups. Or, you can puree and add to muffin or cake batter. And, for a treat, simply slice and bake a banana with the skin on, she suggests.