01/14/2026
Skin Absorption of Essential Oils
The integumentary system is the body's outermost layer, which comprises the skin, hair, nails, and glands. The skin is the body's largest organ, and its primary function is to provide a protective barrier between the body and the external environment, including microorganisms, ultraviolet (UV) radiation, chemicals, allergens, and water loss.
The epidermis (outer layer of the skin) consists of 4 to 5 layers depending on the area of the body: stratum corneum, stratum lucidum (palms and soles only), stratum granulosum, stratum spinosum, and stratum basale.
The dermis is the innermost layer of the skin, consisting of connective tissue, nerve endings, blood vessels, lymphatic vessels, sweat glands, sebaceous glands, and hair follicles.
The skin is permeable, meaning it absorbs substances applied to its surface; therefore, it offers an accessible and convenient site for administering medications by transdermal delivery. For transdermal absorption, the dermis provides minimal interference. The most significant barrier to transdermal absorption is the epidermis. When a transdermal agent passes through the epidermis and reaches the dermis, it gains easy access to blood vessels for systemic circulation.
Essential oil molecules are so minute; therefore, when applied to the skin, their constituents' lipophilic nature and smallness make it easy for them to be absorbed into the bloodstream via the dermis and capillaries. However, many factors affect how much and at what rate the oil is incorporated into the skin, such as the surface area of the application, location of the skin application, technique and exposure time, and temperature. Once in the bloodstream, essential oils deliver therapeutic benefits, like anti-inflammatory, anti-bacterial, antioxidant, anesthetic, and analgesic.
Please note essential oils should be mixed with a carrier oil like sweet almond before applying to the skin, and a skin patch test is advised to eliminate an allergic reaction.