GMS can be synthesized in two ways as mentioned in the manufacturing processes of mono- and diglycerides:

Transesterification process: glycerolysis reaction between fats/oils (hydrogenated oil included) and glycerol (3)
Direct esterification process: esterification between glycerol and the fatty acid – stearic acid
The above raw materials are from the edible sources: animal fats/oils or vegetable oils, especially from the latter, such as palm, rapeseed, soya bean and sunflower oil.

Specification
Other Names   
Glyceryl monostearate
Monostearin
Mono and diglycerides of fatty acids
CAS Number    123-94-4
Chemical formula    C21H42O4
Molecular Weight    358.56
Properties
Appearance
White powder, flake or bead with a slight acidic smell.

Solubility and HLB
GMS has a low HLB value 3-4, it is insoluble in water; soluble in hot oils, hot organic solvents.

As its low HLB property, it is lipophilic and forms water-in-oil emulsions (w/o).

Structure
There are two chemical structures of GMS due to the two places of OH-, and the first isomer takes large part in the final GMS product.