Liquid CBD Oil/Tinctures/Extracts: Drops or tinctures should have a “suggested serving size” and the total milligrams of CBD listed on their packaging. From there, you can determine the amount of CBD you would like to ingest. Simply place the correct quantity of drops under your tongue using the dropper and hold the CBD oil in place for a minimum of 60 seconds. The 60 second hold allows for absorption via the blood vessels underneath your tongue – efficiently bypassing first-pass metabolism. Once 60 seconds has passed, swallow the CBD oil.