Rybelsus and the SOUL Trial: An Oral GLP-1 Now Has a Heart Indication

A pill in the GLP-1 conversation finally has heart data behind it

For most of the GLP-1 era, the cardiovascular story belonged to the shots. SUSTAIN-6 put subcutaneous semaglutide on the map in 2016. LEADER did the same for liraglutide the same year. REWIND brought in dulaglutide in 2019. SELECT, in 2023, stretched the conversation into people without diabetes. FLOW added kidney protection in 2024. Every one of those trials used a needle.

SOUL is the first big trial that didn't.

The New England Journal of Medicine published the SOUL results on March 29, 2025. Two months earlier — on January 28, 2025, timed to the ACC.25 presentation — the FDA had already moved. Rybelsus, the oral form of semaglutide, picked up an indication "to reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes and established cardiovascular disease." It became the first oral GLP-1 to carry that language on its label. As of April 2026, it's still the only one.

The headline number: a 14% relative risk reduction in 3-point MACE. HR 0.86. 95% CI 0.77 to 0.96. p = 0.006. None of those are blockbuster figures. All of them are real.

SOUL in one frame

SOUL stands for Semaglutide cardiOvascular oUtcomes triaL. Novo Nordisk sponsored it. Darren K. McGuire, MD, at UT Southwestern, was the lead principal investigator. The protocol enrolled 9,650 adults with type 2 diabetes who already had established atherosclerotic cardiovascular disease, chronic kidney disease, or both. Everyone was 50 or older. Median follow-up ran about 47.5 months — close to four years.

Patients were randomized to oral semaglutide titrated 3 → 7 → 14 mg over roughly eight weeks, or to placebo. Both arms continued standard-of-care diabetes and cardiovascular medication. That second part matters. Nobody in SOUL was taking the GLP-1 instead of statins, ACE inhibitors, or SGLT2 inhibitors. The MACE reduction landed on top of contemporary care, not in place of it.

The primary endpoint was a composite cardiologists know in their sleep: cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke. 3-point MACE — the same yardstick used in SUSTAIN-6, LEADER, REWIND, and SELECT.

A pill, in 9,650 high-risk patients, beat placebo on hard cardiovascular endpoints. The shots had already shown this. Now the pill has too.

How big is a "14% relative risk reduction"?

This is where summaries usually go sideways, so it's worth slowing down.

A 14% relative risk reduction is meaningful in cardiovascular outcomes work. It is not the 20% that SELECT showed for subcutaneous semaglutide 2.4 mg in obesity without diabetes. It is not the 26% reduction in non-fatal MI that SOUL itself showed (HR ~0.74) as one of the components. It's the composite — heart attacks, strokes, and cardiovascular deaths combined.

The 95% confidence interval (0.77 to 0.96) does not cross 1.0, which is why p = 0.006. The lower bound says the true effect could be as large as a 23% reduction. The upper bound says it could be as modest as 4%. Both ends sit on the protective side of the line.

All-cause mortality, on its own, was not statistically significant in SOUL. Worth saying out loud, because press releases tend to bury it. Cardiovascular composites moved. Total deaths, in this trial, at this follow-up, did not move with statistical confidence.

The honest read: SOUL proved oral semaglutide can do what the injected GLP-1s have been doing — reduce major cardiovascular events in high-risk T2D patients. It did not prove the pill is better than the shot. It did not prove it saves lives outright.

That nuance is the difference between reading the trial and reading the headline.

Where SOUL sits in the GLP-1 cardiovascular timeline

Cardiovascular outcomes trials in this class have been arriving for almost a decade. SOUL is the newest entry, but it slots into a pattern.

The pattern is consistent. Across formulations, doses, and populations, semaglutide-class drugs reduce hard cardiovascular endpoints in patients with diabetes, established disease, or — in SELECT's case — obesity alone. SOUL extends that protection to the oral formulation.

What's deliberately missing from this table: tirzepatide. Mounjaro and Zepbound do not yet carry a cardiovascular indication. SURPASS-CVOT, the dedicated CV outcomes trial for tirzepatide in T2D, is still pending readout as of April 2026. The dual GIP/GLP-1 mechanism may turn out to confer comparable or larger CV benefit. We just don't have the trial to point at yet.

Why a pill matters when the shot already works

Three reasons show up in real prescribing.

Needle aversion is real. A non-trivial share of patients who would benefit from a GLP-1 won't start one because of the injection. Cardiology clinics in particular see older patients who have managed chronic disease for decades and have a hard "no" on weekly self-injection. A daily oral carrying the same molecule, the same drug class, and now the same indication language for cardiovascular risk reduction changes the conversation.

Operational simplicity in CV practice. Cardiologists prescribe pills. Statins, ACE inhibitors, beta blockers, SGLT2 inhibitors, PCSK9-targeted oral agents — the workflow is built for tablets. Adding an oral GLP-1 to that workflow is a much smaller behavioral change than standing up a weekly injection clinic. Route of administration isn't a clinical footnote; it's a clinical adoption variable.

Coverage logistics. In the US, oral and injectable GLP-1s often sit on different formulary tiers and route through different specialty pharmacies. Neither is automatically cheaper. But the PA workflow for an oral diabetes drug with a CV indication is, in practice, more familiar to commercial plans than the workflow for a chronic-weight-management injectable. Rybelsus still isn't easy to get covered. The path is just more conventional.

The pill isn't a replacement for the shot. It's a parallel option — for the patients who want or need that route, and for the prescribers who think about cardiovascular risk before they think about chronic weight management.

How Rybelsus actually has to be taken

Oral semaglutide is unforgiving on this front. Bioavailability for a peptide drug taken by mouth is fragile. Novo Nordisk uses an absorption enhancer called SNAC (sodium N-(8-[2-hydroxybenzoyl] amino) caprylate) to get the molecule across the stomach lining. The dosing ritual exists to make that chemistry work.

Verbatim-adjacent from the label and the counseling sheets US pharmacists hand out:

• Take it on an empty stomach, first thing in the morning.
• Swallow the tablet whole with no more than 120 mL (about 4 oz) of plain water. Not coffee. Not juice. Not tea.
• Wait at least 30 minutes before eating, drinking anything else, or taking other oral medications.
• Titrate up. Start at 3 mg daily for 30 days, move to 7 mg for another 30 days, then settle at 14 mg as the maintenance dose. The 3 mg tier is for tolerability, not therapeutic effect.
• If you miss a dose, skip it. Don't double up.

Take it with breakfast and you lose most of the absorption. Wash it down with a full glass of water and you cut absorption too. The 30-minute fasting window isn't a suggestion — it's the difference between a working drug and an inert tablet. Cardiology and endocrinology teams who prescribe Rybelsus spend extra minutes on this counseling, because adherence to that morning routine is the single biggest predictor of whether the drug works at all.

Mechanism: how GLP-1s protect the heart in the first place

Cardioprotection from GLP-1s isn't one mechanism. It's at least four overlapping ones, and the contribution of each varies by population.

• Weight loss. SOUL participants on oral semaglutide lost weight versus placebo. Lower body weight reduces left ventricular workload, blood pressure, and inflammatory burden. In SELECT — obesity only, no diabetes — this pathway probably did most of the work.
• Glycemic control. Sustained reductions in HbA1c blunt microvascular damage over time. In a T2D population like SOUL's, that's a meaningful contributor to CV risk reduction over four years of follow-up.
• Blood pressure and lipid effects. Modest reductions in systolic BP and triglycerides accumulate. None of these effects are dramatic on their own. Together, over four years, they add up.
• Direct vascular and anti-inflammatory effects. GLP-1 receptors sit on vascular smooth muscle and on certain immune cells. Preclinical and translational work keeps stacking evidence for direct anti-inflammatory and endothelial effects independent of weight or glucose. This is where the mechanism story still has the most unknowns.

So patients whose weight loss is modest may still pick up cardiovascular benefit, because some of the protection isn't weight-mediated. SELECT showed about half the MACE benefit appearing in patients who lost relatively little weight on Wegovy. SOUL is consistent with that pattern.

Side effects in SOUL — boring, expected, on-label

Anyone who has read a GLP-1 trial in the past five years already knows the safety profile. SOUL didn't surprise.

GI events — nausea, diarrhea, constipation, vomiting — were the most common adverse events in the oral semaglutide arm and the most common reason for discontinuation. They cluster early, especially during the 3 → 7 → 14 mg titration window. For most patients they fade after the first 8–12 weeks.

No new safety signal emerged. No excess pancreatitis. No excess in thyroid C-cell tumors at trial-relevant exposure — though the boxed warning for medullary thyroid carcinoma in patients with personal or family history of MTC or MEN 2 syndrome stays on the label. No retinopathy increase at the magnitude SUSTAIN-6 flagged a decade earlier, an effect later analyses largely attributed to the speed of glycemic improvement rather than the molecule itself.

The quiet safety profile is, in its own way, part of the story. A drug class in widespread clinical use since 2017 (subcutaneous semaglutide) and 2019 (oral) isn't springing fresh surprises in CVOT data nearly a decade in.

What this means in the US specifically

US context matters because access patterns and prescriber dynamics aren't the same as anywhere else in the world.

Coverage and cash price. Rybelsus list price in the US runs roughly $1,000/month for the 14 mg maintenance dose, depending on pharmacy and contract. Novo Nordisk's manufacturer savings card can bring out-of-pocket cost down to as low as $25/month for eligible commercially insured patients, with an annual cap. Cash-pay through alternative channels exists, but the savings card is usually the cleanest route for insured patients. Medicare Part D covers Rybelsus for type 2 diabetes; the new MACE indication should, over time, expand the PA criteria some plans use, though formulary updates lag.

Prior authorization mechanics. Express Scripts, CVS Caremark, and OptumRx — the three biggest US PBMs — each handle Rybelsus PA differently. Most plans require documented type 2 diabetes plus an A1c above plan thresholds (typically 7.0% to 7.5%) and a prior trial of metformin. The SOUL-driven CV indication gives prescribers a second pathway: documented established cardiovascular disease in a T2D patient. Whether plans uniformly accept that pathway is still moving in 2026. Endocrinologists and cardiology teams in commercial-payer-heavy regions report the most variation.

Oral versus injectable, in real US prescribing. A 2026 patient choosing between Rybelsus and Ozempic for type 2 diabetes with established CV disease is choosing between a daily morning ritual with strict fasting requirements and a once-weekly injection that demands no behavioral change beyond Sunday morning. Both molecules are semaglutide. Both now carry CV indications. The clinical trade-off is real but small; the lifestyle trade-off is large and personal. Cardiologists historically tilt toward oral when given the choice. Endocrinologists, who manage GLP-1s daily, often tilt toward subcutaneous because the once-weekly cadence improves adherence in their experience. Both perspectives are defensible — and both are worth raising at the visit where the decision gets made.

Foundayo and the broader oral GLP-1 landscape. Eli Lilly's orforglipron — brand name Foundayo — cleared the FDA on April 1, 2026, as the second oral GLP-1 in the US. Foundayo doesn't require fasting and doesn't carry a cardiovascular indication. It's approved for type 2 diabetes and for chronic weight management, at $149/month cash through LillyDirect. So the gap between the two pills is now a clinical decision worth naming: Foundayo brings the convenience, Rybelsus brings the SOUL data and the CV indication. Patients with established ASCVD and T2D who want an oral GLP-1 specifically for cardioprotection still default to Rybelsus in 2026.

Questions to bring to your cardiologist or endocrinologist

If you're reading this because you have type 2 diabetes and existing heart or kidney disease — or because your cardiologist mentioned Rybelsus and you want to walk in informed — these prompts move the conversation forward.

• I have type 2 diabetes and (a prior MI / a stent / known CKD / known peripheral artery disease). Does the SOUL trial change what you'd consider for me?
• I'm already on a statin, an ACE inhibitor or ARB, and (an SGLT2 inhibitor / metformin / insulin). Is adding an oral GLP-1 redundant or additive for my CV risk?
• If we go with Rybelsus, can you walk me through the morning routine — and what happens on days I have early appointments or travel?
• Would I get more cardiovascular benefit from a higher-dose subcutaneous semaglutide than from oral semaglutide at 14 mg, given my profile?
• What's the PA pathway with my plan, and which indication are we coding to — diabetes management or cardiovascular risk reduction?
• If I tolerate Rybelsus poorly during titration, what's the realistic plan B — slower titration, switch to injectable, or step out of the GLP-1 class entirely?
• How will we monitor whether it's working for my CV risk, given that we won't see day-to-day evidence the way we would for blood pressure?

These aren't gotcha questions. Any internist, cardiologist, or endocrinologist worth their salt will be glad you asked — they signal you've read the trial and want to participate in the decision instead of just receiving it.

What to check before starting (or staying on) oral semaglutide

The pre-flight checklist is shorter than for some cardiac drugs, but more behavioral.

• A confirmed type 2 diabetes diagnosis and a documented baseline A1c. Even when Rybelsus is being prescribed primarily for the CV indication, the diabetes documentation has to be in your chart.
• A personal and family history check for medullary thyroid carcinoma and MEN 2 syndrome. The boxed warning is the boxed warning regardless of route.
• A pancreatitis history check. A prior episode isn't an absolute contraindication, but it changes the risk calculus.
• A medication reconciliation. Any other oral medications you take in the morning will need to shift out of that 30-minute fasting window.
• An honest look at your morning routine. Work travel, overnight shifts, and inconsistent breakfast timing all chew through adherence. That isn't a moral failing — it's a practical reason a once-weekly injection might fit better.
• A baseline weight, blood pressure, and lipid panel. Monitoring these over 6–12 months is part of standard GLP-1 care, and watching the numbers move (or not) is how you and your prescriber assess whether the drug is doing its job.
• A frank GI tolerance check if you've been on a GLP-1 before. If subcutaneous semaglutide gave you persistent nausea at 0.5 mg, oral semaglutide at 14 mg has a high chance of doing the same. Class effects don't change with route.

Adherence is the single largest determinant of outcome with oral semaglutide. The trial showed what the drug can do. The morning routine determines whether you get that benefit — every weekday, for years.

What SOUL doesn't settle

The news cycle compresses these out, so they're worth naming directly.

• SOUL studied a T2D population with established ASCVD or CKD. It did not study patients with diabetes alone and no established disease. Cardiovascular benefit in primary prevention with oral semaglutide isn't yet established by trial.
• SOUL did not compare oral semaglutide head-to-head against injectable semaglutide on cardiovascular endpoints. No such trial exists. Cross-trial comparison between SOUL (HR 0.86) and SUSTAIN-6 (HR 0.74) is suggestive but not definitive.
• SOUL did not show a statistically significant all-cause mortality reduction. Larger or longer trials might. This one didn't.
• SOUL did not establish whether oral semaglutide protects the heart in patients without type 2 diabetes. SELECT did that for subcutaneous semaglutide 2.4 mg in obesity. No equivalent trial exists for an oral GLP-1 in that population.
• SOUL did not directly compare against tirzepatide in any form. SURPASS-CVOT will partially answer that question for the dual-agonist class. Until then, the cardiovascular evidence base rests almost entirely on semaglutide and liraglutide.

These caveats aren't reasons to dismiss the trial. They're the borders of what the trial established.

The bottom-line read in April 2026

SOUL did three things that matter.

It proved oral semaglutide reduces hard cardiovascular events in high-risk T2D patients. It gave Rybelsus the first FDA cardiovascular indication ever granted to an oral GLP-1. And it handed cardiology and endocrinology teams a credible non-injectable option for patients who would otherwise refuse a needle.

It didn't prove the pill is better than the shot. It didn't establish CV protection outside the studied population. It didn't move all-cause mortality on its own. The 14% relative risk reduction is real. It's also smaller than the SELECT and SUSTAIN-6 numbers in different populations. The shape of the data is consistent with a class that protects the heart, with some variation across formulations and risk profiles.

If you and your cardiologist or endocrinologist are weighing whether oral semaglutide fits your situation, SOUL gives that conversation a sturdier floor than it had a year ago. Bring the questions above to your next visit. Read the prescribing information. Ask honestly whether your morning routine can carry the 30-minute fasting window five mornings out of seven, every week, for years.

The drug now has the data. The next part is whether it fits your life.

Sources

• McGuire, D.K., et al. Oral Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes. New England Journal of Medicine, March 29, 2025.
• US FDA — Rybelsus label expansion announcement, January 28, 2025.
• American College of Cardiology — ACC.25 Scientific Sessions, SOUL primary results presentation.
• Novo Nordisk — Rybelsus prescribing information (current US label).
• Marso, S.P., et al. Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes (SUSTAIN-6). NEJM, 2016.
• Lincoff, A.M., et al. Semaglutide and Cardiovascular Outcomes in Obesity Without Diabetes (SELECT). NEJM, 2023.
• Perkovic, V., et al. Effects of Semaglutide on Chronic Kidney Disease in Patients with Type 2 Diabetes (FLOW). NEJM, 2024.

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