Answering the narrow version, because the broad one does not have a single answer. The OASIS programme put 50mg oral in the same territory as 2.4mg injectable — around 15% mean weight loss — but it needed a dose 20 times larger to get there because almost none of the tablet is absorbed. The dose numbers are not comparable across routes and quoting them side by side confuses people.
That is the short version; the long version is somebody else's post.