Does semaglutide as a pill work just as well as the injection?
For weight loss, the pill (25 mg daily) and the injection (2.4 mg weekly) are comparably effective. If you have diabetes there is more uncertainty; discuss with your doctor which form suits you best.
A direct comparison of two large randomised trials shows that the pill and the injection produce comparable weight loss. The injection (2.4 mg per week) scored numerically about 1 percentage point better than the pill (25 mg per day), but that difference is too small to be clinically relevant. The FDA applies a threshold of 5 percentage points for that.
For blood sugar treatment in diabetes the picture is slightly more mixed. Real-world data from 292 Italian patients show that the injection performed better than the pill on all measured outcomes (blood sugar, weight, waist circumference). But that comparison is skewed: the injection was more often given to younger patients with more excess weight. This makes it difficult to compare the outcomes fairly.
Why does the pill need such a high dose in the first place? The pill absorbs the medication through the intestines, which is inherently far less efficient than an injection. At low doses only a small amount reaches the bloodstream. Higher doses (25 mg) compensate for this: in most users blood levels are then comparable to those of the injection, as pharmacokinetic modelling shows.
Side effects are comparable with both forms and consist mainly of gastrointestinal complaints. With the 14 mg pill, 15 to 20 percent of users experienced nausea. These complaints appeared early and diminished over time. Between 5 and 8 percent discontinued because of these complaints.
Cost completes the picture: both forms are virtually equivalent in terms of price per cardiovascular event prevented. When the pill is compared with other injectable agents from the same class, the pill scores well on cost-effectiveness, although the analyses were partly conducted by researchers affiliated with the manufacturer.
The weight loss figure comes from a direct comparison of two randomised trials (OASIS 4 and STEP 1). The pharmacokinetic data were partly measured in healthy volunteers and partly simulated through modelling, not measured in a large patient group. The real-world data on diabetes treatment come from a single retrospective cohort of 292 patients, in which the distribution of patients across the two groups was unequal. The cost analyses were partly conducted by researchers with ties to the manufacturer, and work with prices and populations from 2019 and the United States.