Semaglutide and Kidney Disease: What the FLOW Trial Found

Kidney disease is a major concern for many people with type 2 diabetes. The FLOW trial tested semaglutide in adults with type 2 diabetes and chronic kidney disease (CKD), asking whether treatment changed the risk of serious kidney and cardiovascular outcomes. Its results helped move the GLP-1 conversation beyond blood sugar and weight.

Who was in FLOW?

FLOW enrolled 3,533 adults with type 2 diabetes and CKD, defined by both reduced kidney filtration (eGFR) and protein in the urine (albuminuria) within set ranges. Participants were randomly assigned to weekly semaglutide 1.0 mg (an Ozempic dose) or placebo, on top of their usual care.

What did FLOW find?

The primary outcome was a composite of kidney failure (dialysis, transplant or very low eGFR), a drop in eGFR of at least 50%, or death from kidney-related or cardiovascular causes.

• The trial was stopped early for efficacy after a planned interim analysis, with a median follow-up of 3.4 years.
• A primary-outcome event occurred in 331 people on semaglutide versus 410 on placebo, a 24% lower relative risk (hazard ratio 0.76).
• Kidney function declined more slowly with semaglutide, and the risks of major cardiovascular events and of death from any cause were also lower.
• Serious adverse events were reported slightly less often with semaglutide (49.6%) than placebo (53.8%).

FLOW was funded by Novo Nordisk, the manufacturer.

What did the FDA approve?

In January 2025, the US FDA added a kidney indication to Ozempic. As of October 2026, the US label says Ozempic is indicated to reduce the risk of sustained eGFR decline, end-stage kidney disease and cardiovascular death in adults with type 2 diabetes and chronic kidney disease. That indication belongs to Ozempic specifically; Wegovy, Rybelsus and other GLP-1 products have their own labels. Approvals can also differ outside the US.

Does that mean every GLP-1 drug is a kidney medicine?

No. Evidence varies by molecule, dose, indication and population. A result for semaglutide in people with type 2 diabetes and established CKD shouldn't be rewritten as a claim that every GLP-1 product treats every kidney condition, or that people without diabetes would see the same effect. For a broader look at how complication evidence differs from drug to drug, see GLP-1 medicines and diabetes complications.

Kidney health and dehydration

GLP-1 medicines can cause gastrointestinal symptoms such as vomiting or diarrhea. Significant fluid loss can lead to dehydration and, in some cases, acute kidney injury, which is a different issue from the long-term benefit seen in FLOW. Contact your care team if you can't keep fluids down, are urinating much less than usual, or feel very dizzy or weak. If you have kidney disease, a fluid restriction or medicines that affect kidney function, ask your clinician for individualized advice. Our guide to GLP-1 medicines and dehydration covers this in more detail.

What to ask at a visit

• Does the FLOW evidence apply to my type of kidney disease?
• Which kidney measures (like eGFR and urine albumin) will we track, and how often?
• How would this fit with my current diabetes and blood-pressure plan?

Please don't adjust other prescriptions or your fluid intake based on a blog post.

The main lesson is that kidney outcomes are now part of the GLP-1 evidence conversation, but the exact drug and population are crucial. A strong trial result is not a substitute for your kidney team's individualized plan.