Yes, milk thistle can be used to support the treatment of fatty liver (steatosis hepatis). The main active ingredient in milk thistle, silymarin, has liver-protecting, antioxidant and anti-inflammatory properties, which can be particularly useful in liver diseases such as fatty liver. Several studies have shown that the regular intake of milk thistle preparations can improve liver function in people with fatty liver. Nevertheless, the treatment of fatty liver should always include a change in lifestyle, such as a healthy diet, weight loss and regular physical activity.