Grapefruit is the name applied to two distinct Sativa-dominant strains. The first is known as BC Grapefruit and the second as Nectar's Grapefruit. Both strains provide powerful uplifting feelings of euphoria and impart energy, with Nectar's Grapefruit often described as also exhilarating. Although their Sativa heritages produce similar effects, the strains differ in other ways. The Nectar's strain's effects tend to be more internal, often giving rise to deep thought, while BC Grapefruit causes users to feel more social and talkative. Both strains have common negative effects: dry mouth and eyes, dizziness, paranoia, and anxiety.

These strains can be good as daytime medication, especially for relieving stress and anxiety, though Nectar's may need to be relegated to times when users do not need to focus.  The cerebral effects are good for battling depression and some forms of insomnia. Patients may also find that Grapefruit makes their minor aches and pains more manageable. It is not recommended, however, for severe chronic aches and pains. More Indica-heavy strains are usually prescribed for that purpose (see strains most frequently prescribed for pain here.)

BC Grapefruit comes from a clone of unknown genetics. Breeder Steve from Spice of Life found the clone, which had been labeled the one to grow. It gained some popularity in the 80s but was clone only. Other breeders have created seeds by back-crossing the strain. True BC Grapefruit has since become very scarce. The strains derived from BC Grapefruit carry a THC range of 15% -20% and grow well both outside and indoors. They flower for 55 to 60 days.

Nectar's Grapefruit is a cross between C99/Cinderella 99 and an unknown landrace Sativa devised by Nectar Seeds. Like BC Grapefruit, it can grow both indoors and outside but has a longer flowering time of 60 to 69 days.