L-beta-hydroxybutyrate has epigenetic effects and signaling functions.

“So you have the D that gets burned up quickly for fuel and then the L that kind of hangs around gets metabolized slower but then that's hitting the various receptors. So you have the GP uh GPR 109A receptor and you have you have epigenetic effects. You have the NLRP3 inflammosome. So you have uh important signaling functions that ketones are attributed to and deba hydroxybutyrate has been sort of spent and used as fuel but the L is hanging around and actually uh preserving uh that signaling effect the positive signaling effect”