Excessive oiliness in the skin, termed seborrhoea , is predominantly caused by the hyperactivity of sebaceous glands, responsible for sebum production, the lipid-rich, oily substance that serves to moisturise and safeguard the skin.

The sebaceous glands can be stimulated by a variety of factors, including diet, hormonal changes and stress, as well as environmental factors, over washing and the use of skin care products that are too harsh or drying to the skin.

Overstimulation of the sebaceous glands can lead to excessive sebum production, which may result in the appearance of oiliness on the skin, trigger inflammation and contribute to the development of acne lesions.

Blue light has been clinically demonstrated to regulate sebum production within the skin by influencing the proliferation of human sebocytes and thus down-regulating lipid production.