At a glance
- STRIDE Phase 3b enrolled 792 adults with symptomatic Fontaine IIa PAD plus type 2 diabetes across 20 countries and 112 sites
- Primary endpoint: median maximum walking distance rose 13% more on semaglutide 1 mg than placebo at 52 weeks (estimated treatment ratio 1.13, 95% CI 1.06-1.21, p=0.0004)
- Absolute treadmill gain: median 26 m and mean ~40 m of walking distance over the placebo arm at 52 weeks
- Pain-free walking distance and VascuQol-6 quality of life both improved on semaglutide vs placebo; ABI also improved
- STRIDE results apply only to adults with type 2 diabetes plus symptomatic PAD. The trial did not test semaglutide in PAD without diabetes
The first new PAD walking drug in 25 years
Cilostazol was approved by the FDA for intermittent claudication in 1999. A quarter century later, no new medical therapy had moved the treadmill needle for peripheral artery disease in a placebo-controlled Phase 3 trial. The STRIDE trial changes that for the subset of patients who also have type 2 diabetes.
Semaglutide 1.0 mg once weekly, given on top of standard PAD care for 52 weeks, increased median maximum walking distance by 13 percent over placebo in symptomatic PAD with concomitant type 2 diabetes (Bonaca et al., Lancet 2025, DOI 10.1016/S0140-6736(25)00509-4; see also the STRIDE design paper, Bonaca et al., Eur Heart J Cardiovasc Pharmacother 2024, PMID 39424598). Pain-free walking distance, the VascuQol-6 quality-of-life score, and ankle-brachial index all improved alongside the primary endpoint.
Bottom line: STRIDE is the first positive Phase 3 functional trial in PAD in over two decades, but the result is narrow. The trial only enrolled adults with type 2 diabetes plus Fontaine IIa intermittent claudication. The 26-meter median absolute gain is modest in raw meters and meaningful in context: this population had run out of pharmacologic options.
This piece walks through what STRIDE actually measured, where the treatment effect lands against existing PAD therapies, where the data stop, and how to read the result honestly. For the broader semaglutide picture, our semaglutide compound guide covers the molecule, and our SELECT cardiovascular MACE evidence guide and FLOW kidney evidence guide cover the other landmark outcome trials.
What STRIDE was designed to answer
PAD with intermittent claudication produces a specific, measurable disability: walking pain that limits how far someone can move before stopping. The treadmill test is the standard surrogate. A constant-load treadmill runs at fixed speed and fixed incline, and the endpoints are pain-free walking distance (the distance before claudication symptoms begin) and maximum walking distance (the distance at which the patient must stop).
Cilostazol, a phosphodiesterase-3 inhibitor approved in 1999, is the only currently approved oral drug for intermittent claudication. Pooled trial data put cilostazol's treadmill effect at roughly 30 to 50 meters of added walking distance at 100 mg twice daily versus placebo (Thompson et al., Vasc Med 2002, PMID 12473004). Supervised exercise therapy beats cilostazol on raw meters in the head-to-head CLEVER trial (Murphy et al., Circulation 2012, PMID 22090168), but access to supervised exercise programs remains the limiting factor for most patients in real-world practice.
STRIDE asked a simple question: does semaglutide, already proven to reduce major adverse cardiovascular events in patients with overweight or established atherosclerosis, also improve functional capacity specifically in the legs of patients with symptomatic PAD?
The design (Bonaca et al., 2024 design paper, PMID 39424598; main results Lancet 2025):
- Phase 3b, double-blind, randomized, placebo-controlled
- 792 adults across 112 outpatient sites in 20 countries (North America, Asia, Europe)
- Inclusion: age 18+, type 2 diabetes, symptomatic PAD with Fontaine stage IIa intermittent claudication, ankle-brachial index 0.40 to 0.90 or toe-brachial index 0.30 to 0.70
- Intervention: semaglutide 1.0 mg subcutaneously once weekly versus placebo, on top of standard PAD care including antiplatelet, statin, and structured exercise advice
- Duration: 52 weeks of treatment, plus a 5-week off-drug observation window for the residual-effect endpoint
- Primary endpoint: ratio of maximum walking distance at week 52 to baseline, semaglutide versus placebo
- Secondary endpoints included pain-free walking distance, VascuQol-6 quality-of-life score, ankle-brachial index, and HbA1c
The trial population was specifically chosen to combine the two conditions that drive the highest amputation and cardiovascular event risk in modern vascular medicine: PAD and diabetes together.
The primary endpoint, in numbers
The headline number from STRIDE is a ratio, not an absolute distance. That matters for interpretation.
At week 52, the estimated treatment ratio for maximum walking distance was 1.13 (95% CI 1.06 to 1.21, p = 0.0004), meaning the semaglutide group's median maximum walking distance grew 13 percent more than the placebo group's. In absolute terms, the median treatment difference at 52 weeks was about 26 meters and the mean treatment difference was about 40 meters on a constant-load treadmill.
| Endpoint | Semaglutide 1.0 mg | Placebo | Effect estimate |
|---|---|---|---|
| Maximum walking distance (week 52, ratio to baseline) | +21% (median, approx.) | +8% (median, approx.) | ETR 1.13, p=0.0004 |
| Pain-free walking distance (week 52) | Improved vs placebo | Reference | p=0.0046 |
| VascuQol-6 quality of life | Improved vs placebo | Reference | p=0.011 |
| Ankle-brachial index | Improved vs placebo | Reference | Significant |
Source: Bonaca et al., Lancet 2025, DOI 10.1016/S0140-6736(25)00509-4; ACC.25 presentation summary in the editorial commentary by Brzezinski and Sanders, PMID 40466625.
Three details deserve attention beyond the ratio:
- The baseline median maximum walking distance in STRIDE was around 186 meters. A 26-meter median absolute gain is roughly a 14 percent absolute improvement at the median, which lines up with the 13 percent ratio result.
- The mean and median differ because the distribution of treadmill response is skewed. Most patients improved modestly. A subset improved substantially. The mean of 40 meters captures the long-tail responders that the median understates.
- The treatment ratio held at week 57, five weeks after the last dose, suggesting at least short-term durability of the effect after stopping the drug. Whether the effect persists past that window is not answered by STRIDE.
One number is worth holding in your head from STRIDE: 13 percent more walking distance at 52 weeks. Everything else is downstream of that.
How the result compares to existing PAD therapies
Cross-trial comparisons in PAD walking outcomes are directional, not definitive. Trial populations differ, treadmill protocols differ, and the placebo arms behave differently from study to study. With those caveats, the rough positioning of STRIDE against established PAD therapies:
| Therapy | Pivotal evidence | Approximate treadmill gain | Approval/access | Population |
|---|---|---|---|---|
| Cilostazol 100 mg BID | Meta-analysis of 8 RCTs (Thompson et al., Vasc Med 2002, PMID 12473004) | ~30-50 m absolute MWD gain | FDA-approved 1999 | Symptomatic PAD, broad |
| Supervised exercise therapy | CLEVER (Murphy et al., Circulation 2012, PMID 22090168) | Largest gain vs medical therapy at 6 mo | Guideline-recommended, access-limited | Symptomatic PAD, broad |
| Endovascular revascularization | CLEVER (Murphy et al., Circulation 2012) | Comparable to exercise at 6 mo, durable to 18 mo | Procedural, indication-dependent | Aortoiliac PAD |
| Semaglutide 1.0 mg weekly | STRIDE (Bonaca et al., Lancet 2025) | Median ~26 m, mean ~40 m at 52 wk | Approved for T2D/obesity; PAD use off-label | PAD + T2D only (per trial inclusion) |
Two patterns sit inside this table.
First, the raw treadmill gain in STRIDE lands in the same ballpark as cilostazol's pooled effect from the older meta-analytic data. That is not a dismissal of STRIDE. It is a calibration. Cilostazol's effect on walking distance has been the modern reference point for "the best a drug can do" in PAD, and STRIDE puts semaglutide in that same range on top of existing standard care, in patients who likely already had access to cilostazol if appropriate.
Second, supervised exercise programs remain the most effective non-procedural intervention for PAD walking capacity. The CLEVER trial put supervised exercise ahead of medical therapy at both 6 and 18 months for aortoiliac disease. Semaglutide is not a substitute for supervised exercise. It is an additional lever in a population that has historically had limited options to stack on top of exercise and antiplatelet care.
The secondary endpoints that round out the picture
The maximum walking distance result was the regulatory primary, but STRIDE was powered to read the supporting secondaries cleanly, and the supporting endpoints moved in the same direction.
Pain-free walking distance improved significantly on semaglutide at 52 weeks compared to placebo (p = 0.0046). This is the symptom-driven endpoint that maps most directly onto patient experience: the distance before claudication pain starts, not the distance before they must stop. A patient who reaches half a mile pain-free has a meaningfully different daily life than one who reaches a tenth of a mile.
VascuQol-6, a six-item disease-specific quality-of-life instrument, also improved on semaglutide versus placebo (p = 0.011). The VascuQol-6 differs from generic QoL instruments because it captures vascular-symptom-specific items like leg pain interfering with daily activities and walking limitations affecting social activities. The improvement on this scale is consistent with the walking-distance gain rather than coming from generalized GLP-1 wellness effects.
Ankle-brachial index, the hemodynamic measure of lower-extremity perfusion, also improved significantly on semaglutide. ABI is not symptom-driven, it is anatomy- and flow-driven. An ABI improvement in a randomized trial with this duration suggests a real vascular effect beyond the metabolic effects on weight, HbA1c, and lipid panel that semaglutide is already known to produce.
A pre-specified sub-analysis published separately found that the treatment effect on maximum walking distance was directionally similar in both men and women, with no statistically significant sex difference in the primary outcome (STRIDE sex differences sub-analysis, JACC 2025, PMID 40892617).
The pattern across the secondaries is what gives the primary endpoint its weight. A 13 percent walking-distance ratio in isolation might be dismissed as treadmill-protocol artifact. A 13 percent walking-distance ratio that runs alongside concordant pain-free walking, vascular-specific quality of life, and ankle-brachial index gains is much harder to attribute to noise.
How semaglutide might be acting in PAD
The biology is genuinely uncertain. Semaglutide is a GLP-1 receptor agonist. GLP-1 receptors are expressed in vascular smooth muscle and endothelial cells, but the receptor density and signaling consequences in the peripheral vasculature have not been fully characterized in humans.
Three mechanistic candidates are plausible:
- Metabolic effects translated to vascular biology. Lower HbA1c, body weight, systolic blood pressure, and improved lipid profile all modify the underlying atherosclerotic disease that produces PAD.
- Direct vascular signaling. GLP-1 receptor agonism in animal models has been associated with reduced vascular inflammation, modestly increased nitric oxide bioavailability, and altered smooth muscle behavior.
- Microvascular and skeletal-muscle metabolic effects. Semaglutide may alter substrate utilization in the calf muscles that limit claudication walking distance. ABI improvement argues for a partly hemodynamic explanation, but muscle-level metabolic effects cannot be ruled out from STRIDE data alone.
STRIDE establishes the clinical fact (semaglutide improves walking capacity in this population) without establishing the mechanism. An accompanying editorial frames the result as having implications for how the broader GLP-1 receptor agonist class will be evaluated in vascular disease (editorial, PMID 40466625).
Safety profile in STRIDE
The adverse-event signal in STRIDE was class-typical for GLP-1 receptor agonism, with the usual gastrointestinal symptoms (nausea, decreased appetite, diarrhoea) dominating. The trial population was older (median age around 68), had a median diabetes duration of approximately 12 years, and was already on multiple cardiovascular medications, so tolerability in this specific population is a relevant safety read.
Two safety considerations carry particular weight in the PAD context:
- Sarcopenia and lean mass. GLP-1 receptor agonists drive a meaningful fraction of total weight loss from lean tissue. In a PAD population that depends on calf muscle for walking capacity, accelerated lean mass loss could plausibly counteract the vascular gains. Our GLP-1 muscle loss research roundup covers the preservation strategies that hold up across the class.
- Hypoglycemia. The trial enrolled patients with type 2 diabetes already on background therapy. Adding semaglutide to insulin or sulfonylureas raises hypoglycemia risk; STRIDE did not report severe hypoglycemia excess on semaglutide, but the management requirement applies in real-world use.
The cardiovascular safety question is settled separately by the SELECT and FLOW programs and now reinforced by the SOUL trial for oral semaglutide (Meeting summary, Heart Fail Rev 2025, PMID 41370018). STRIDE did not need to establish cardiovascular safety because the parent program already had.
Who STRIDE actually applies to
The trial population matters more than the headline number when deciding whether STRIDE changes a specific patient's options. The inclusion criteria define the boundary of the evidence.
| STRIDE inclusion | Outside STRIDE inclusion |
|---|---|
| Type 2 diabetes | Type 1 diabetes; non-diabetic adults with PAD |
| Symptomatic intermittent claudication (Fontaine IIa) | Asymptomatic PAD; critical limb ischemia (Fontaine III/IV) |
| ABI 0.40-0.90 or TBI 0.30-0.70 | ABI below 0.40 (severe) or above 0.90 (borderline) |
| Stable on antiplatelet, statin, BP therapy | Recent revascularization (<3 months) |
| Able to walk on a treadmill | Walking limitation primarily from non-vascular cause (e.g., spinal stenosis, severe arthritis) |
The strongest case for using the STRIDE evidence is an adult with type 2 diabetes and a stable claudication phenotype who is on guideline-directed medical therapy and who has walking limitation that is clearly vascular in origin. That is the patient who appeared on enrollment forms in STRIDE.
Evidence is weakest, and the data do not extend, to PAD patients without diabetes. Whether the result generalizes to that population is the open question for the next trial, and it is not safe to assume the answer is the same.
Note: The Endocrinology Advisor and ACC summaries of STRIDE emphasize that the trial design specifically required type 2 diabetes for enrollment. Generalizing the walking-distance benefit to non-diabetic PAD patients is not supported by the trial.
How STRIDE fits into the broader semaglutide indication map
STRIDE is the latest in a series of large outcome trials that have steadily widened semaglutide's evidence base beyond glycemic control.
| Trial | Population | Primary outcome | Status |
|---|---|---|---|
| SELECT | Overweight/obesity with prior CVD, no diabetes | -20% MACE | Approved (CV indication) |
| FLOW (Perkovic et al., NEJM 2024, PMID 38785209) | T2D + CKD | Major kidney events reduced | Approved (CKD indication) |
| STEP 9 | Obesity + knee osteoarthritis | Knee pain (WOMAC) improved | Pain indication evidence |
| SURMOUNT-OSA (tirzepatide) | Obesity + OSA | AHI reduced | Approved (OSA) |
| STRIDE (Bonaca et al., Lancet 2025) | T2D + symptomatic PAD | Walking capacity improved | Functional evidence, no specific PAD label yet |
| SOUL (oral sema) | T2D + ASCVD/CKD | 14% MACE reduction (review, PMID 41370018) | Approved CV-risk indication evidence |
The pattern across this set is that semaglutide effects are showing up wherever obesity, diabetes, and atherosclerosis intersect with a functional endpoint that can be cleanly measured. For deeper coverage of the parallel evidence pieces, our SELECT cardiovascular MACE evidence guide, FLOW CKD evidence guide, and STEP 9 knee osteoarthritis evidence guide cover the adjacent indications in detail.
A natural next question is whether tirzepatide produces the same walking-distance effect in PAD. There is no equivalent Phase 3 PAD trial for tirzepatide as of May 2026, and SURMOUNT-MMO (the cardiovascular outcomes trial) is not powered to read PAD function as a primary endpoint. Until a comparable trial reads out, STRIDE is the only Phase 3 PAD evidence in the dual-incretin and GLP-1 class.
What STRIDE does not prove
A clean read of STRIDE has to include what the trial did not test or did not show.
- Non-diabetic PAD. Every randomized patient had type 2 diabetes. STRIDE does not address PAD patients without diabetes.
- Critical limb ischemia. Patients with Fontaine III or IV (rest pain or tissue loss) were not enrolled.
- Amputation risk. Not powered as an endpoint. The trial reported on function, not on limb salvage.
- Long-term durability beyond 52 weeks. The 5-week off-drug window suggests short-term residual benefit; persistence at 2 or 3 years is an open question.
- Head-to-head vs cilostazol or supervised exercise. STRIDE was placebo-controlled. No comparative trial exists in this population.
These boundaries are not weaknesses of the trial. STRIDE answered the question it was designed to answer. They matter because that question is narrower than the way the result is being summarized in general medical press.
Warning: STRIDE does not authorize self-administration of semaglutide for PAD. The trial was conducted in patients with type 2 diabetes already on guideline-directed medical therapy under specialist supervision. Adapting STRIDE to your own situation requires individual clinical assessment, particularly because PAD often coexists with conditions (severe hypoglycemia risk, advanced CKD, gastroparesis history) that change the risk profile.
What this means in practice
If you are a clinician or researcher reading STRIDE, the realistic mental model is:
- For adults with type 2 diabetes and stable, symptomatic Fontaine IIa PAD on standard medical therapy, semaglutide 1.0 mg weekly is now an evidence-supported adjunct. The walking-distance gain is modest in absolute meters but consistent across primary and supporting endpoints, and the underlying cardiovascular benefit is already established by SELECT and SOUL.
- Semaglutide does not replace cilostazol, supervised exercise, antiplatelet therapy, statin therapy, or smoking cessation. It stacks on top of standard PAD care.
- For PAD without diabetes, the evidence does not yet exist. Off-label semaglutide use for non-diabetic PAD is extrapolation from a trial that did not enroll the population in question.
- For dose, STRIDE used the 1.0 mg once-weekly dose, not the 2.4 mg obesity dose. The diabetes-aligned dose was the trial dose, and that is the dose with PAD functional evidence.
- For monitoring, the same baseline considerations that apply to any GLP-1 initiation apply here: pancreatitis history, medullary thyroid carcinoma history, gastroparesis history, and concurrent insulin or sulfonylurea use.
For practical reconstitution math for any GLP-1 class peptide, our reconstitution calculator handles the unit conversions, and our GLP-1 dosing comparison guide covers the dose-equivalency math across the class.
Where to source semaglutide
Approved semaglutide for type 2 diabetes (Ozempic) and obesity (Wegovy) is available through prescription channels and remains the safest path for any patient who fits a labeled indication. Compounded semaglutide remains available in some jurisdictions under specific FDA enforcement guidance. See our compounded tirzepatide legal access guide and the generic semaglutide patent expiry timeline.
For research-grade semaglutide with verified per-batch certificates of analysis, our partner Ascension Peptides carries the injectable format. Code ENHANCED takes 50 percent off the catalog. Third-party purity testing, public COAs, and source-to-vial traceability are non-negotiable for any research compound used in patients with pre-existing vascular disease. The same vendor framework applies that we cover in best legit peptide vendors 2026.
STRIDE used Novo Nordisk's commercial semaglutide product. Research-grade material is not bioequivalent to the trial product by default and should not be assumed to reproduce STRIDE outcomes outside a study setting.
Honest evidence summary
- Efficacy: 13 percent relative gain in maximum walking distance at 52 weeks (ETR 1.13, 95% CI 1.06-1.21, p=0.0004), median 26 m and mean ~40 m absolute, with concordant gains in pain-free walking, VascuQol-6, and ABI.
- Safety: GI-dominant adverse-event profile consistent with the rest of the GLP-1 class. No new safety signal specific to PAD.
- Generalizability: Restricted to adults with type 2 diabetes and symptomatic Fontaine IIa PAD on standard care. Non-diabetic, severe, and asymptomatic PAD were not studied.
- Bottom line: STRIDE is the first positive Phase 3 functional trial in PAD in over 25 years. The result is real, the magnitude is modest, the population is specific, and broader GLP-1 class implications wait on future trials.
This article is for educational and informational purposes only. It is not medical advice. The STRIDE trial established functional walking-capacity improvement in adults with type 2 diabetes and symptomatic peripheral artery disease, but does not authorize self-administration of semaglutide for PAD or any other indication. Semaglutide carries known risks including gastrointestinal adverse events, pancreatitis, contraindications in medullary thyroid carcinoma, and hypoglycemia when combined with insulin or sulfonylureas. Decisions about PAD management require individual assessment by a qualified clinician familiar with vascular disease, diabetes management, and current treatment guidelines.
