Alexander's research for hairstyles in the TV series included pre-Raphaelite artists, and painters like John William Waterhouse and Dante Gabriel Rossetti.
There are about 20-30 wigs used for major characters in the TV series. Some such as Daenerys Targaryen actually have three separate wigs on-call at any time (because her wig is white and gets dirty easily). Some of the wigs for main cast members can cost as much as $7,000 each (the longer ones cost more). The wigs are made of real human hair, sourced from India, Europe, and Russia. Cersei Lannister's wig, in particular, does not undergo any chemical processing at all: the wig maker sourced individual colors and strands of hair, which were then individually knotted onto a lace cap for her golden blonde blend. Other actors such as Kit Harington (Jon Snow) and Sophie Turner (Sansa Stark) do not wear wigs, but have their hair dyed.