What is the white substance inside a milia?

The white substance inside milia is a keratin buildup, primarily composed of dead skin cells, sebum, and lipid mixtures. It is a benign accumulation caused by abnormal skin metabolism and does not pose serious health risks. However, if milia suddenly increase in number, or are accompanied by redness, swelling, pain, or infection, medical attention is recommended.

When the skin's keratin layer fails to shed properly, accumulated dead skin cells can block hair follicle openings. Sebum produced by sebaceous glands cannot be discharged normally and mixes with these keratinocytes, gradually forming small, hard, white, semi-solid particles.

Microscopic dust from the environment or residue from skincare products may also enter clogged follicles, mixing further with metabolic waste and exacerbating the buildup, making the milia more visible and their texture harder.

In daily skincare, choose lightweight, easily absorbed products. Avoid heavy creams or eye creams, keep the skin clean without over-exfoliating, and use gentle moisturizers to support normal keratin turnover and reduce milia formation.