Which skin layer is primarily affected during facials?

The epidermis is the outermost layer of the skin and is primarily what is affected during facials. Facials are designed to cleanse, exfoliate, and treat this layer, promoting a healthy appearance and function. Treatments often target the epidermis to remove dead skin cells, improve texture, and hydrate the skin.

While the dermis also plays a critical role in overall skin health and various procedures may indirectly benefit the dermis, facials primarily focus on the epidermis to achieve visible results such as improved skin tone and reduced blemishes. The hypodermis, which is the deepest layer of skin, is not directly involved in most facial treatments as it is primarily composed of fat and connective tissues that provide insulation and cushioning rather than participating in aesthetic improvements.

Additionally, the stratum corneum, which is the outermost sub-layer of the epidermis, is influenced during facials because it's where exfoliation occurs, but since the question asks about the skin layer as a whole, the epidermis is the correct choice as it encompasses the stratum corneum along with other components of the upper skin layer.