This product is made from 100% GOTS-certified organic cotton rib, yay!
Because this fabric is 100% cotton, it will shrink a little when you launder it, like a pair of jeans. Don't worry! This is normal. It'll stretch back out as you wear it. Also the initial shrinking won't be very noticeable.
It's always advisable to air dry cotton rather than putting it in the dryer—it'll shrink less, and it's better for the environment.