What are the benefits and drawbacks of taking oral bio identical progesterone relative to cream?

Oral progesterone. is metabolized by the liver to pregnenolone which helps with sleep. This is both a pro and a con- Sleep is very important ,and I think outweighs the negative effect of the liver metabolism.
Don't use it. Stop using it. Bioidentical 'natural progesterone' does not contain any Progesterone at all, and often contain plant extracts that are estrogenic in effect. In my clinical view there is no good use for these creams. Talk with your doctor about alternatives to accomplish what you need.