"Barbells are way more popular. They’re more subtle under clothes and they heal faster because they don’t move around as much,” says Thompson. Barbells also allow for more room for swelling: “I like to allow at least an eighth of an inch on each side of the nipple, between the ball.” This allows for the fluctuation. Plus, it’s easier to accidentally hit or pull a hoop than a barbell. One more thing while we’re on the subject: You want to go with an internally threaded barbell, not an externally threaded one, which means the bar is smooth and won’t create irritation and tiny cuts while going in or out of the piercing.