While grapefruit oil is safe to use in cooking, it's best to dilute it with a carrier oil like coconut or jojoba oil. It is also great for sore muscles, and can help improve digestion after meals. Inhale it to help relieve headaches, bloating, and retained water in the body. And it can even improve your mood and reduce stress. However, it is best to buy pure essential oils from a reputable source.