Some oils are Generally Regarded As Safe (GRAS) or certified Food Additives (FA) by the FDA and can be safely taken internally as a dietary supplement.  Some oils like orange and lemon listed below are more effective taken orally and can make great refreshing (and Low-Carb) drinks to quench thirst!

I add 1-2 drops in my 12 oz. glass of water for an uplifting drink in the morning or midday.  This is a great change of pace from water all day long without any sugar!

Orange Oil (Citrus aurantium) is rich in the powerful antioxidant d-limonene. It also brings peace and happiness to the mind and body.  Properties include: uplifting, joy, generosity feeling, antioxidant, alleviate nervousness, cleansing, calming, and relaxing.

Lemon Oil (Citrus limon) has antiseptic-like properties when diffused. It contains 68 percent d-limonene, a powerful antioxidant. It may serve as an insect repellent and may be beneficial for the skin.  Properties include: uplifting, cheerful, refreshing, antioxidant, immune support, cleansing and antiseptic.