Skin supplements are an increasingly popular way to enhance the skin’s health and appearance. These supplements are safe, natural, and can be taken used both orally and topically. On this glossary page, we are going to cover the key terms relevant to skin health and supplementation.
Epidermis
The outer layer of the skin which serves as a physical barrier from the outside environment. The epidermis consists mostly of cells called keratinocytes, and has a total of 5 layers. The bottom-most layer is called the stratum basale, where new keratinocytes are produced to replace the dead ones being shed at the surface of the skin.
Extracellular matrix
The non-cellular components of tissues that provide the biological “scaffolding” for cells and serve other roles. In the skin, the matrix is mainly composed of collagen and hyaluronic acid.
Fibroblast
A type of cell found in the skin and other connective tissue. Fibroblasts are most notable for producing collagen and other key structural components of the skin, such as glycoaminoglycans. Certain skin supplements can stimulate fibroblasts.
Horny layer (stratum corneum)
The topmost layer of the epidermis that consists of dead skin cells (corneocytes). The stratum corneum functions as a physical barrier to infection, water loss, and skin damage. It is made up of multiple cell layers held together with a lipid matrix made out of ceramides, cholesterol, and fatty acids.
Keratin
A structural protein found in the skin, as well as hair, nails, horns, and other tough structures in mammals. Keratin is the key component responsible for the protective properties of the skin’s epidermis, where it is found in keratinocyte cells.
Keratinocyte
The main type of cell found in the skin’s epidermis. Keratinocytes are composed primarily of keratin, and help form a protective barrier against the outside environment.
Oxidative stress
A state in which the body’s antioxidant defenses are unable to effectively neutralize reactive oxygen species (ROS) – compounds that can cause damage to cells. In the context of skin health, oxidative stress plays a central role in both natural and sun-induced skin aging.
Photoprotection
Protection against the sun’s ultraviolet radiation. Photoprotection is key for preventing UV-induced skin aging.The skin’s outer epidermis layer has natural photoprotective properties, and sunscreen also provides photoprotection.
Reactive oxygen species (ROS)
Compounds formed as a normal byproduct of the body’s use of oxygen. ROS can cause damage to cells, and this damage plays a central role in the aging of skin. Most notably, ROS levels in the skin are increased after sun exposure.
Transepidermal water loss (TEWL)
The loss of water from inside the body through the skin’s topmost epidermis layer. TEWL increases as we age and due to certain skin conditions, and is frequently used in skin studies to measure how effectively a supplement improves the skin’s ability to retain water.
Ultraviolet (UV) light
A type of radiation emitted from the sun. Exposure to ultraviolet light is the main preventable cause of skin aging. Many skin supplements (and sunscreens) help protect the skin from damage caused by UV radiation.
