As Farmington Hills, Mich.-based Living Essentials LLC’s 5 Hour Energy brand suggests in its advertising, “that 2:30 feeling” can be difficult for many consumers to overcome. In fact, that mid-afternoon slump, or “post-lunch dip,” is a natural part of humans’ internal clock, which creates the urge to sleep approximately seven hours after waking, according to a 2007 New York Times article.