Source Naturals Promilin(TM) Fenugreek Extract combines two potent extracts; one, a patent pending extract called Promilin(tm), is standardized to contain 20% 4-hydroxyisoleucine; the other is rich in galactomannan fibers. Research suggests that both 4-hydroxyisoleucine and galactomannan fibers help support healthy blood sugar and insulin levels when used as part of your diet.