Limonene: Found in high concentrations in citrus fruits, Limonene is known for its mood enhancing effects. It’s often associated with fruity, citrus aromas, and is found in many everyday items like fruit rinds, cosmetics, and cleaning products. It's believed to provide anxiety and stress relief. Studies have shown potential in elevating moods, relieving heartburn and gastric reflux and improving absorption of other terpenes by way of the skin, mucous membranes and digestive tract; and also may have anti-fungal and antibacterial properties. Additionally, in lab rodents, limonene inhibited growth of skin and mammary tumors. There have been many studies done which suggest limonene causes tumor cell death in various forms of cancer.