Does injectable semaglutide have a higher glucose-lowering efficiency than oral semaglutide?  

There is a modestly lower average exposure from 14 mg of oral semaglutide than from 1 mg of injected semaglutide. But, the important issue is that the absorption of semaglutide from the stomach is exquisitely dependent on how it is administered, and probably that is the driver of greater variability...