Cannabis oils are best taken under the tongue (sublingually) to help the body absorb as much of the cannabis as possible. Inevitably, some of the oil will be swallowed and taking cannabis with food is known to increase the absorption by up to four times compared to taking it on an empty stomach. Putting cannabis under the tongue for as long as comfortable (up to 10 minutes), then swallowing with or after foods is sensible advice to get the most out of the oils.