Tallow (specifically grass-fed tallow) just happens to be the best thing to use on human skin because:

of it's similarity to sebum (because it's compatible, it can soak deeper into the skin's layers)
it has high levels of vitamins, minerals, and antioxidants
it's the highest source of a VERY essential fatty acid called CLA (more on this below)
it's great for every skin type: dry, oily, combination, mature, sensitive, super-duper sensitive