HerbalFactors® Milk Thistle by Natural Factors $23.09 60 Capsules - $23.09 90 Capsules - $29.69 Size 60 Capsules 90 Capsules 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart Natural Factors Milk Thistle extract contains standardized silymarin and is considered to be one of the highest quality milk thistle extracts in the world. Research has shown that milk thistle extract promotes healthy liver function.*