Furocoumarins are a special type of coumarin, and fall within the subgroup of lactones. Examples include bergaptene, bergaptol, and psoralen. Furocoumarines can be phototoxic and may also interfere with anticoagulant medications.
Bergamot is an essential oil containing bergaptene. Other essential oils containing bergaptene may include lime, orange, and grapefruit. Essential oils labeled FCF that normally contain furocoumarins, have been rectified to remove these constituents.
Furocoumarins can be found in the following foods: grapefruit, lemon, lime, orange, carrot, parsnip, celery, parsley, dill, cilantro, cumin, turnip, and coriander.