Planetary Herbals Full Spectrum Silymarin 80 is a highly concentrated extract of milk thistle seeds (Silybum marianum), which modern research has shown supports many aspects of a healthy liver. This extract delivers a total of 168 mg of silymarin, which is a mixture of flavanolignans including silybin, silydianin and silychristin, and matches the constituent profile of extracts used in human research studies. Extra milk thistle seeds are added to ensure the presence of important secondary compounds.