Semaglutide started as a diabetes drug, then became known for weight loss. In 2024, a trial called FLOW showed it does something else too: it slows the progression of chronic kidney disease. Here's what the trial found, and who the finding actually applies to.
FLOW was a phase 3, double-blind, placebo-controlled trial that enrolled 3,533 adults who had both type 2 diabetes and chronic kidney disease — defined by a reduced eGFR, significant albuminuria, or both. Participants were randomized to weekly subcutaneous semaglutide at 1.0 mg (the standard Ozempic dose) or placebo, on top of their usual care.
The primary outcome was a composite of major kidney events: onset of kidney failure requiring dialysis or transplant, an eGFR that fell below 15, at least a 50% drop in eGFR from baseline, or death from kidney-related or cardiovascular causes. Median follow-up was 3.4 years.
FLOW was halted ahead of schedule after an interim analysis showed a clear benefit — a step trial monitoring boards only take when continuing would mean withholding a working treatment from the placebo group. The semaglutide group had 331 primary-outcome events versus 410 in the placebo group, a 24% relative risk reduction (hazard ratio 0.76, 95% CI 0.66–0.88, P = 0.0003).
Secondary findings tracked the same direction: cardiovascular death was lower by about 18%, all-cause mortality by about 20%, and the average yearly decline in eGFR was slower by 1.16 mL/min/1.73m² in the semaglutide group — a meaningful difference in a disease where the whole game is slowing decline.
On January 28, 2025, the FDA expanded Ozempic's label based on FLOW, making it the first and only GLP-1 approved specifically to reduce the risk of worsening kidney disease and cardiovascular death in adults with type 2 diabetes and chronic kidney disease.
Sources: Perkovic V, et al. "Effects of Semaglutide on Chronic Kidney Disease in Patients with Type 2 Diabetes." N Engl J Med 2024. pubmed.ncbi.nlm.nih.gov/38785209. FDA approval: National Kidney Foundation, "FDA Approves Ozempic for Type 2 Diabetes and Chronic Kidney Disease," Jan 2025.
The finding is specific. FLOW enrolled people who already had both type 2 diabetes and diagnosed chronic kidney disease, dosed at semaglutide 1.0 mg weekly — the Ozempic regimen, not the higher 2.4 mg Wegovy dose used for weight management. It does not establish a kidney-protective effect for people without diabetes, or for people taking semaglutide purely for weight loss without an existing CKD diagnosis. Those are open questions, not settled ones.
What FLOW does reinforce is something adjacent to the point of this app: the benefit was measured over a median of 3.4 years of consistent, uninterrupted weekly dosing. Trials like this only work — and outcomes like a slower eGFR decline only show up — when the shot actually happens on schedule, week after week, for years. A missed dose here or there in real-world use isn't captured in a trial protocol, but it's the difference between the treatment you're prescribed and the treatment you actually get.
This article summarizes findings from a specific published trial. It does not establish that semaglutide benefits kidney function in people without type 2 diabetes and CKD, and it is not a substitute for guidance from your prescriber about your own kidney function or medication regimen.