A 369:

"Substituting blood for a costly material component requires drawing a greater amount of blood. A tainted sorcerer deals more damage to herself when drawing a large amount of blood, as shown on the table below. Also, when using blood to replace a costly component in this way, the tainted sorcerer must make a Concentration check (DC 10 + damage taken + spelllevel) to successfully cast the spell."

http://www.dandwiki.com/wiki/UA:Tainted_Sorcerer