Mark Kristal, professor of psychology and a noted placentophagia expert (whose research has shown that placenta ingestion is beneficial to non-human mammals)
There is no valid scientific evidence yet that eating placenta has any health benefits for humans. All of the information so far is anecdotal and is spread primarily by doulas, midwives and placenta encapsulators. The anecdotes and surveys indicate that the method of preparation doesn’t matter, the amount ingested doesn’t matter, and the time it is eaten relative to delivery doesn’t matter. Furthermore, it appears from these reports to help a wide variety of problems and ailments. That puts it into the realm of a placebo, not a medical remedy.