Lemon oil is extracted from the peel of the Citrus limon plant. It is used in aromatherapy, the lemon essential oil has the number of health benefits. Lemon oil is typically used to ease stress, fight fatigue and insomnia, and address conditions such as acne, athlete's foot, depression, warts, and varicose veins. lemon oil also stimulates the immune system, alleviates pain, and promotes weight loss.