After getting lip fillers, it is recommended to sleep with your head elevated for the first few nights to reduce swelling. You can do this by propping up pillows or sleeping in a recliner. It is also best to sleep on your back to avoid putting pressure on your lips. Avoid sleeping on your side or stomach for at least 48 hours after the procedure. Additionally, avoid rubbing or touching your lips while sleeping to prevent infection or displacement of the fillers.