Phosphatidylserine is an important phospholipid membrane component which plays a key role in cell signalling. It is very wide spread in animal products because it is the part of the structural component that each cell membrane of every animal cell is made of. If you are regularly eating meat and eggs in your diet, there is really no need to supplement with it. If you are a vegan, the supplement might have some merit but for someone eating meat at least once per day, I highly doubt you will notice anything at all from supplementing with it.
That being said, it will do NOTHING for liver function. If you want a liver aid supplement, look for a supplement based on TUDCA, NAC and milk thistle. I recommend the product N2guard from n2bm.com.