Table 1.

Chemical composition of normal human meibum and sebum

Component	Human meibum (Butovich et al., 2016)	Human sebum (Nakahara et al., 2015; Picardo et al., 2009; Thiboutot, 2004)
	Percentage of total lipids, % (w/w)
(O)-Acylated ω-hydroxy fatty acids (OAHFA)	1–5	none reported
Cholesteryl esters	30–40	3–6
Ceramides	traces	none reported
Free cholesterol	<0.5	1–3
Cholesteryl esters of OAHFA	3	none reported
Diacylated diols	Reported, not quantitated	none reported
Free fatty acids	~0.1–1	6–40
Phospholipids and sphingomyelins	<<0.1	none reported
Squalene	traces	10–20
Glycerides	1 (mostly, triolein)	20–80
Wax esters	30–48	20–30