Oral Semaglutide vs Injectable Semaglutide: What the Heart Health Research Shows

By Katie Sorensen, NP-C | Weight Loss NP

GLP-1 medications are no longer just being discussed as just weight loss medications.

They are increasingly being studied for heart health, kidney health, inflammation, metabolic risk, and long-term prevention. For patients with obesity, prediabetes, type 2 diabetes, or cardiovascular disease, this matters.

A big question is whether oral semaglutide has the same impressive cardiovascular risk reduction prowess as injectable semaglutide. We took a look at the research.

“Is oral semaglutide as good as injectable semaglutide for the heart?”

No Surprise: The answer is more nuanced than a plain yes or no.

The research on oral semaglutide is encouraging, especially for people with type 2 diabetes and high cardiovascular risk. Injectable semaglutide also has strong cardiovascular outcomes data, including an FDA-approved cardiovascular risk reduction indication for Wegovy in certain adults with overweight or obesity and established cardiovascular disease.

But oral and injectable semaglutide have not been compared head-to-head in a large cardiovascular outcomes trial. So we aren’t able to directly know which is really better htan another but we do have some emerging data to go off of.

Here is what the research actually shows.

Why cardiovascular risk matters in medical weight loss

Weight loss is not just about the scale. It’s about metabolic health, and chronic disease risk reduction.

For many patients, the bigger goal is reducing long-term health risks, including:

• Heart attack
• Stroke
• High blood pressure
• Insulin resistance
• Type 2 diabetes
• Chronic kidney disease
• Fatty liver disease
• Sleep apnea
• Inflammation
• Loss of mobility and function

This is why medically supervised weight loss is different from a diet plan. At Weight Loss NP, we look at the whole metabolic picture: weight history, blood sugar risk, blood pressure, cholesterol, medications, hormones, nutrition, strength, and whether GLP-1 treatment is appropriate.

Learn more about our medical weight loss services.

What PIONEER 6 showed about oral semaglutide

The 2019 New England Journal of Medicine PIONEER 6 trial studied once-daily oral semaglutide in people with type 2 diabetes who were at high cardiovascular risk.

The purpose of the trial was mainly to show cardiovascular safety. In research terms, it was designed to prove that oral semaglutide was not worse than placebo by an unacceptable amount, rather than being primarily designed to prove superiority.

In PIONEER 6:

• 3,183 patients were randomized to oral semaglutide or placebo
• The mean age was 66
• Most participants had established cardiovascular disease, chronic kidney disease, or both
• Major adverse cardiovascular events occurred in 3.8% of the oral semaglutide group versus 4.8% of the placebo group
• The hazard ratio was 0.79, but the trial did not show statistically significant superiority for the primary cardiovascular outcome
• Cardiovascular death and death from any cause were lower in the oral semaglutide group
• Gastrointestinal side effects leading to discontinuation were more common with oral semaglutide

The practical takeaway: PIONEER 6 supported cardiovascular safety and suggested possible cardiovascular benefit, but it was not the final word on cardiovascular risk reduction.

What the newer SOUL data added

The newer SOUL trial gave us stronger evidence for oral semaglutide in high-risk patients with type 2 diabetes.

According to the American Diabetes Association press release on oral semaglutide cardiovascular outcomes, SOUL included 9,650 adults age 50 or older with type 2 diabetes and either known atherosclerotic cardiovascular disease, chronic kidney disease, or both.

Participants received once-daily oral semaglutide up to 14 mg or placebo, in addition to standard care.

The primary outcome was major adverse cardiovascular events, which includes cardiovascular death, nonfatal heart attack, or nonfatal stroke.

The results showed:

• 12.0% of patients in the oral semaglutide group had a primary outcome event
• 13.8% of patients in the placebo group had a primary outcome event
• Oral semaglutide was associated with a 14% lower risk of major adverse cardiovascular events
• The hazard ratio was 0.86
• Serious adverse events were not increased compared with placebo

The American College of Cardiology summary of SOUL also describes oral semaglutide as being associated with a lower risk of three-point MACE in people with type 2 diabetes and established cardiovascular disease, chronic kidney disease, or both.

The practical takeaway: oral semaglutide now has stronger cardiovascular outcomes data for people with type 2 diabetes and high cardiovascular risk.

What we know about injectable semaglutide and heart risk

Injectable semaglutide also has important cardiovascular data.

In SUSTAIN-6, injectable semaglutide was studied in people with type 2 diabetes at high cardiovascular risk. The primary outcome occurred in 6.6% of patients receiving semaglutide compared with 8.9% receiving placebo, with a hazard ratio of 0.74.

In the SELECT trial, weekly injectable semaglutide 2.4 mg was studied in adults with overweight or obesity and established cardiovascular disease, but without diabetes. A primary cardiovascular endpoint event occurred in 6.5% of the semaglutide group compared with 8.0% of the placebo group, with a hazard ratio of 0.80.

That SELECT data led to an important regulatory milestone. In March 2024, the FDA approved Wegovy injection to reduce the risk of cardiovascular death, heart attack, and stroke in adults with cardiovascular disease and either obesity or overweight.

The practical takeaway: injectable semaglutide has strong cardiovascular risk reduction data, including data in patients without diabetes who have overweight or obesity and established cardiovascular disease.

Oral semaglutide vs injectable semaglutide: which is better at reducing risk of cardiovascular disease?

Both oral and injectable semaglutide have cardiovascular outcomes data, but the findings come from different trials.

For oral semaglutide, the PIONEER 6 trial showed a 21% relative reduction in major adverse cardiovascular events compared with placebo, with a hazard ratio of 0.79. However, this trial was designed primarily to prove cardiovascular safety, or noninferiority, and did not show statistically significant superiority for the primary cardiovascular outcome.

The newer SOUL trial provided stronger evidence for oral semaglutide in high-risk patients with type 2 diabetes. In SOUL, oral semaglutide showed a 14% relative reduction in major adverse cardiovascular events compared with placebo, with a hazard ratio of 0.86.

For injectable semaglutide, the SUSTAIN-6 trial in high-risk patients with type 2 diabetes showed a 26% relative reduction in major adverse cardiovascular events compared with placebo, with a hazard ratio of 0.74.

In the SELECT trial, weekly injectable semaglutide 2.4 mg, marketed as Wegovy, showed a 20% relative reduction in cardiovascular death, nonfatal heart attack, or nonfatal stroke in adults with overweight or obesity and established cardiovascular disease, but without diabetes.

The important caveat is that these trials studied different populations, doses, formulations, and endpoints. They were not designed as direct oral-versus-injectable comparisons. So while we can describe the risk reductions seen in each trial, we should not interpret them as proving that oral semaglutide is better, worse, or equal to injectable semaglutide for every patient.

The better takeaway is this: oral semaglutide now has meaningful cardiovascular outcomes data in people with type 2 diabetes and high cardiovascular risk. Injectable semaglutide has meaningful cardiovascular outcomes data in both type 2 diabetes and in people with overweight or obesity and established cardiovascular disease, including an FDA-approved cardiovascular risk reduction indication for Wegovy injection.

When oral semaglutide may make sense

Oral semaglutide may be appealing for patients who:

• Strongly prefer pills over injections
• Have type 2 diabetes and need help with blood sugar and cardiometabolic risk
• Have high cardiovascular risk and are appropriate candidates
• Struggle with injection fear or injection fatigue
• Need a medication plan that fits their daily routine

However, oral semaglutide has specific administration rules. It usually needs to be taken on an empty stomach with a small amount of water, and patients need to wait before eating, drinking, or taking other medications. That can make consistency harder for some people.

When injectable semaglutide may make sense

Injectable semaglutide may be a better fit for some patients because:

• It is once weekly rather than daily
• It may be easier to remember
• Wegovy injection has an FDA-approved cardiovascular risk reduction indication for certain patients with overweight or obesity and established cardiovascular disease
• It has robust weight loss and cardiovascular outcomes data
• It may be more practical for patients who struggle with the strict oral dosing instructions

For patients using semaglutide primarily for weight loss, injectable semaglutide has historically been the more established option. Oral semaglutide use depends on diagnosis, dose availability, coverage, medical history, and the specific clinical goal.

Learn more about our GLP-1 weight loss program.

What this means for patients in Denver, Colorado, Utah, and Florida

At Weight Loss NP, we help patients in Colorado, Utah, and Florida understand their options for medical weight loss, GLP-1 medications, diabetes risk reduction, and long-term metabolic health.

For some patients, the priority is weight loss. For others, it is blood sugar, heart risk, kidney risk, blood pressure, mobility, sleep apnea, or long-term maintenance.

The best medication choice depends on:

• Your diagnosis
• Your cardiovascular history
• Your blood sugar and A1C
• Your kidney function
• Your insurance coverage
• Your medication tolerance
• Your ability to follow dosing instructions
• Your weight loss goals
• Your long-term maintenance plan
• Whether you need weight loss medication, diabetes medication, cardiovascular risk reduction, or a combination

This is why GLP-1 care should be medically guided, not based only on ads, social media, or whether a medication is a pill or a shot.

The bottom line

Oral semaglutide is becoming a solid option in cardiometabolic care.

The PIONEER 6 trial showed cardiovascular safety and suggested possible benefit. The newer SOUL trial showed a significant reduction in major adverse cardiovascular events in high-risk people with type 2 diabetes.

Injectable semaglutide also has strong cardiovascular outcomes data, including the FDA-approved Wegovy indication for reducing cardiovascular death, heart attack, and stroke in adults with cardiovascular disease and overweight or obesity.

The most important question is not simply “oral or injectable?”

The better question is:

“What medication, dose, monitoring, nutrition plan, and long-term strategy best fits my health history and goals?”

At Weight Loss NP, we help patients answer that question with medical guidance, practical support, and a plan built for real life.