When you consume these capsules, the BHB is absorbed into your bloodstream and can cross different vital barriers to be converted into energy at all times. One of the most important areas where this happens is in the brain. The blood-brain barrier (BBB) is usually a tightly regulated interface, but since BHB is hydrophilic, your brain knows to let it in for energy. This is one of the main reasons why increased BHB levels lead to heightened mental acuity.