oxytocin is a hormone released by the
View full size image. Oxytocin is a hormone secreted by the posterior lobe of the pituitary gland, a pea-sized structure at the base of the brain. It's sometimes known as the cuddle hormone or the love hormone, because it is released when people snuggle up or bond socially. Even playing with your dog can cause an oxytocin surge, according to a 2009 study published in the journal Hormones and Behavior.