Oral vs. Injectable Semaglutide (GLP-1 Agonist): What Does Real World Research Show?
Oral Wegovy pill and Rybelsus, injectable Wegovy and Ozempic, they all have same active ingredient called Semaglutide which is a GLP-1 agonist, used for treatment of diabetes as well as weight loss. It’s important to understand that oral pills and injectables must not be used interchangeably for diabetes and weight loss as doses used to treat both are very different. Let’s understand it's effect on Diabetes and weight loss through one research. A 2024 study published in the Journal of Pharmacy Technology has provided real-world insights into how two formulations of semaglutide perform for managing type 2 diabetes. The research, conducted at the University of Rochester Medical Center, directly compared the effectiveness and safety of oral and injectable semaglutide over a 26-week period.[1]
Background on the Study
For context, semaglutide belongs to a class of medications known as glucagon-like peptide-1 receptor agonists (GLP-1 RAs). The injectable form has been available since 2014 and is commonly prescribed for type 2 diabetes due to its effectiveness and ease of use. The oral formulation, approved in 2019, represented the first oral option in this drug class. While both forms exist, there had been limited head-to-head real-world comparisons between them until now.[1]
What Researchers Examined
The study reviewed 105 patients with type 2 diabetes who received either oral semaglutide (7 mg or 14 mg daily) or injectable semaglutide (0.5 mg or 1 mg weekly) between late 2019 and mid-2022. Researchers tracked two primary measures: changes in hemoglobin A1C (HbA1C), a marker of blood sugar control over time, and changes in weight.[1]
The study population was fairly representative of real-world patients. About 54% were male, the median age was 60 years, and most patients were already taking other diabetes medications like metformin (76%) or insulin (52%). This design makes the findings relevant to how these medications actually work outside of controlled clinical trials.[1]
Key Findings on Blood Sugar Control
Both groups experienced meaningful reductions in HbA1C over the 26-week period. Patients on oral semaglutide saw an average decrease of 1.75%, while those on injectable semaglutide experienced a 1.35% decrease. When directly compared, the oral formulation showed a 0.4% greater numerical reduction in HbA1C, though this difference was not statistically significant.[1]
Looking at specific doses, patients on the 14 mg oral dose saw the largest HbA1C reduction at 2.43%, compared to 0.85% in the 7 mg group. For the injectable formulation, the 1 mg weekly dose produced a 1.70% reduction versus 0.95% for the 0.5 mg dose.[1]
By the end of the study, about 56% of patients on oral semaglutide and 55% on injectable semaglutide achieved the target HbA1C level of less than 7%. These percentages increased when researchers looked at any point during the study period, with about 74% and 77% reaching this goal for oral and injectable groups respectively.[1]
Weight Loss Outcomes
Injectable semaglutide showed a slight advantage for weight reduction. Patients on the injectable form lost an average of 5.26 kg, compared to 3.64 kg in the oral group. The injectable formulation demonstrated a 1.62 kg greater numerical weight loss, though again this difference was not statistically significant.[1]
Looking at clinically meaningful weight loss (defined as at least 5% of total body weight), just over 39% of oral semaglutide users achieved this during the study period, while about 55% of injectable users did. However, when researchers looked at any point during the study, these percentages increased to 48% and 66% respectively.[1]
Safety and Side Effects
An important distinction emerged in how the two formulations were tolerated. Adverse events occurred in 16.7% of the oral semaglutide group compared to only 4.9% of the injectable group. Nausea was the most common side effect in both groups, followed by diarrhea. Four patients discontinued therapy due to gastrointestinal side effects, with three of them in the injectable group and one in the oral group.[1]
This lower adverse event rate in the injectable group is noteworthy for patients concerned about tolerability. However, it's worth noting that these figures may be lower than clinical trial reports because the study relied on documented medical records rather than formal adverse event screening that typically occurs in controlled trials.[1]
What About Clinical Practice?
The study offers several practical observations. Patients who were not taking insulin alongside semaglutide were more likely to achieve HbA1C targets of less than 7%. Additionally, a lower baseline HbA1C (under 8.5%) was associated with better HbA1C goal achievement in both groups.[1]
Interestingly, the presence of a clinical pharmacist at the patient's primary care office didn't significantly impact outcomes in this study, though the authors acknowledge that roughly 23% of patients had access to this resource.[1]
How Do These Results Compare?
Researchers compared their findings to landmark clinical trials. The oral semaglutide results were slightly better than what appeared in the PIONEER trials (1.8% average reduction versus 1.1%), while the injectable results were comparable to the SUSTAIN trials (1.4% versus 1.56%).[1]
The weight loss results from this real-world study were somewhat better than clinical trials, which researchers attribute to the higher baseline weight in their patient population (average 106.9 kg versus 88-92 kg in trials) and concurrent use of other medications that contribute to weight loss.[1]
Study Strengths and Limitations
The study's main strength is that it reflects actual clinical practice. Patients were on additional diabetes medications and had varied baseline health metrics—representing the reality of diabetes care. The 26-week timeframe provides useful information for decisions typically made at 3- and 6-month clinic visits.[1]
However, there are limitations. This was a single-center, retrospective review, meaning researchers relied on existing medical records. The study period coincided with the COVID-19 pandemic, which affected follow-up appointment availability and limited the sample size. The researchers acknowledge that the relatively small number of patients, particularly in certain dose groups, may have contributed to some unexpected findings.[1]
What to take away from this study and way forward
This real-world comparison suggests that oral and injectable semaglutide are broadly comparable for HbA1C reduction, with oral semaglutide showing slightly better average HbA1C reduction and injectable semaglutide showing slightly better weight loss. Neither difference reached statistical significance. Injectable semaglutide demonstrated better tolerability with fewer reported adverse events and discontinuations due to side effects.[1]
For patients and providers, this data supports individualized treatment selection. Oral semaglutide might be preferable for someone focused on blood sugar control and comfortable with pill-based therapy, while injectable semaglutide might be better for someone prioritizing weight loss or concerned about gastrointestinal side effects.[1]
The authors conclude that more large-scale real-world studies are needed to confirm these findings and explore whether the newer 2 mg once-weekly injectable dose might offer additional benefits.[1]
Sources:
[1] Pinto M, Brennan L, Diehl K, Lin S, Heacock S. Real-World Comparison of Oral Versus Injectable Semaglutide for the Reduction of Hemoglobin A1C and Weight in Patients with Type 2 Diabetes. J Pharm Technol. 2025 Feb;41(1):22-31. doi: 10.1177/87551225241289959. Epub 2024 Nov 5. PMID: 39545243; PMCID: PMC11559783.
About the Author
