Since you cannot eat grapefruit to test its ripeness it is good to know grapefruits generally ripen from September to October and can remain on the tree for several months. If it is a ruby red grapefruit, some of the pink color will show up on the outer skin to signify it may be ready to pick during the peak months. Many of us cannot eat grapefruit as it interacts with some important medications.
According to Harvard Health, dangerous interactions can occur when grapefruit is combined with drugs used to manage high blood pressure, high cholesterol and depression. People taking ED drugs should also avoid grapefruit juice. Doctors are not sure which chemicals in grapefruit cause issues, but many believe the primary candidate is furanocoumarin. It is important to note, this chemical is also found in Seville (sour) oranges, limes, pomelos and tangelos; although these fruits have not been studied in detail, the guidelines for grapefruit should also apply to them.
If you are on a low or moderate dose of the medication, you can probably get away with an occasional glass of grapefruit juice, but if you are on a high dose, it could be dangerous. That’s especially true in the case of calcium channel blockers, which can lower your blood pressure or slow your heart rate excessively.