in pictures and a few words
What it is and why it matters
Finerenone is a prescription pill. It slows kidney failure in type 2 diabetes and lowers the risk to the heart.
- It is not a hormone, not a water pill and not a pill for blood sugar
- It is added to the blood pressure pills that protect the kidneys, not used instead of them
- It does not replace control of blood sugar and blood pressure
Why kidneys tire in diabetes
Years of high blood sugar damage the kidney’s filters. First protein appears in the urine, then the kidney filters worse and worse.
- At the same time, an adrenal hormone triggers inflammation in the kidney
- The kidney’s working tissue is gradually replaced by scar
How it works
Finerenone intercepts this hormone’s signal. The signal does not get through — there is less inflammation and scarring in the kidney.
- Blood pressure pills that protect the kidneys block this pathway only partly
- Over time the hormone rises again — finerenone closes this gap
What the studies showed
Two large studies in thousands of people with type 2 diabetes and kidney disease.
- Kidneys: kidney disease got worse less often
- Heart: fewer heart and blood vessel complications
- You won’t feel the benefit: it shows only in test results
Tested in people. Tested in people: finerenone was compared with a dummy pill in people with type 2 diabetes and kidney disease.
How it differs from spironolactone
Spironolactone also acts on this hormone, but it affects sex hormones as well. Finerenone is built differently.
- With spironolactone, men’s breasts may grow and hurt, and women’s cycles may be disrupted
- Finerenone does not cause these effects
- It holds on to potassium less, but checking potassium is still a must
Who it is prescribed for
Adults with kidney disease due to type 2 diabetes. Usually when there is protein in the urine and kidney function is reduced or falling. In the US it is also prescribed for one type of heart failure.
- On top of blood pressure pills that protect the kidneys, at the highest dose you tolerate
- Alongside diabetes pills that also protect the kidneys — not instead of them
- Not for prevention if your kidneys are healthy, and not for swelling
The dose depends on the kidneys
The dose is chosen by how well the kidneys filter the blood. This value is calculated from a blood test.
- Filtration of 60 mL/min/1.73 m² or higher — 20 mg a day from the start
- From 25 to 60 — start with 10 mg, then 20 mg if tolerated and potassium is fine
- Below 25 — starting is not recommended
Keeping potassium in check
The main risk is high blood potassium: it disturbs the heart rhythm. A routine blood test catches it in time.
- Potassium above 5.0 mmol/L — treatment is not started
- Potassium rising — the dose is lowered or paused, and restarted once it is normal
- The risk is higher if you already take other medicines that hold on to potassium
Important. Don’t skip potassium tests: they are a required part of treatment.
Who should see a doctor first
Finerenone is prescription-only: a doctor prescribes it after tests. Three things are checked before starting.
- Blood potassium and creatinine — it is used to calculate how well the kidneys work
- A urine test: is there protein in it, and how much
- Tell your doctor about all your medicines, especially those that hold on to potassium; avoid grapefruit
Important. It is not started if potassium is above 5.0 mmol/L, kidney filtration is below 25, the adrenal glands are underactive, or you take certain medicines for fungal and other infections.
In one sentence
Finerenone is added to your usual medicines so that, in type 2 diabetes, kidney disease progresses more slowly and the risk to the heart is lower. Potassium is kept in check with blood tests.
In brief
Why kidneys fail in diabetes
Years of high glucose damage the glomeruli, the kidney's filters. Protein begins to leak through them (albuminuria), and filtration then declines slowly. In parallel a second, less obvious mechanism switches on: aldosterone, the adrenal hormone, acts on the mineralocorticoid receptor in kidney tissue and drives inflammation and fibrosis — the replacement of working tissue with scar.
ACE inhibitors and ARBs partly suppress that path, but over time an escape phenomenon appears: aldosterone rises again. That is precisely the gap finerenone closes.
How it differs from spironolactone
| Spironolactone | Finerenone | |
|---|---|---|
| Structure | Steroidal | Non-steroidal |
| Hormonal side effects | Gynaecomastia, breast tenderness, cycle disturbance | Not characteristic |
| Distribution | More in the kidney | More even between kidney and heart |
| Potassium retention | Marked | Weaker, but monitoring required |
| Evidence in diabetic nephropathy | Limited | Two large outcome trials |
What the trials showed
▸FIDELIO-DKD (NEJM, 2020; n=5,734) — kidney outcomes. Reduced risk of disease progression: sustained decline in filtration, progression to end-stage disease and renal death [1]. ▸FIGARO-DKD (NEJM, 2021; n=7,437) — cardiovascular outcomes. Reduced event rates in the same patient category [2]. ▸An individual-participant meta-analysis (Lancet, 2026) confirms the effect across both lines [3].
For nephrology this is an unusual situation: a drug that improves outcomes for both kidney and heart.
Who it is for
▸adults with chronic kidney disease in type 2 diabetes; ▸typically with albuminuria and reduced or declining filtration; ▸on top of an ACE inhibitor or ARB at the maximally tolerated dose; ▸per the FDA label (rev. 09/2026), also adults with heart failure with LVEF ≥40% (FINEARTS-HF, NEJM 2024 PMID 39225278); separate dosing, target up to 40 mg.
Who it is not for: patients with potassium above 5.0 mmol/L at baseline, an estimated GFR below 25 mL/min/1.73 m², adrenal insufficiency, concomitant strong CYP3A4 inhibitors (e.g., itraconazole, clarithromycin), or anyone seeking "kidney prevention" without documented renal involvement. Avoid grapefruit and grapefruit juice.
Dosing and monitoring in diabetic kidney disease
| Estimated GFR, mL/min/1.73 m² | Starting dose | Target |
|---|---|---|
| 60 and above | 20 mg/day | 20 mg/day |
| 25–60 | 10 mg/day | 20 mg/day if tolerated |
| Below 25 | Initiation not recommended | — |
Potassium monitoring is part of the therapy, not an optional extra:
▸before starting — potassium, creatinine with eGFR, urine albumin-to-creatinine ratio; ▸at 4 weeks — potassium and eGFR; the uptitration decision follows from these; ▸at every dose change — repeat check; ▸if potassium rises — reduce the dose or pause, resuming after it normalises.
How it fits with everything else
Modern management of diabetic kidney disease rests on several pillars, and they are not interchangeable:
| Class | What it works through |
|---|---|
| ACE inhibitors and ARBs | Glomerular pressure, reduction of urinary protein |
| SGLT2 inhibitors | Intraglomerular haemodynamics, metabolic effects |
| Finerenone | Suppression of inflammation and fibrosis in kidney tissue |
| GLP-1 receptor agonists | Metabolic control, weight, cardiovascular protection |
Finerenone is added to that structure rather than displacing parts of it.
What matters in practice
▸The effect is not felt. The drug relieves no symptoms — it changes the trajectory of a disease visible only in laboratory results. Hence the familiar adherence problem. ▸Potassium is not a formality. It is the one genuinely demanding element of this therapy, and an ordinary blood test settles it. ▸It does not replace glucose and blood-pressure control. Without those, any nephroprotective drug works at half strength. ▸It is prescription-only, started by a clinician after assessing filtration, albuminuria and potassium.
Prescribing can be discussed at a consultation; the product can be ordered here.
References
1. Bakris GL, et al. Effect of finerenone on chronic kidney disease outcomes in type 2 diabetes (FIDELIO-DKD). N Engl J Med. 2020;383(23):2219–2229. PMID 33264825
2. Pitt B, et al. Cardiovascular events with finerenone in kidney disease and type 2 diabetes (FIGARO-DKD). N Engl J Med. 2021;385(24):2252–2263. PMID 34449181
3. Neuen BL, et al. Efficacy and safety of finerenone in patients with chronic kidney disease: an individual participant data meta-analysis. Lancet. 2026. PMID 42248158
4. KERENDIA (finerenone) US Prescribing Information, Bayer HealthCare Pharmaceuticals.
Key facts
- Finerenone (brand name Kerendia, Bayer) is a non-steroidal mineralocorticoid receptor antagonist. It is neither a hormone nor a diuretic: it intercepts the aldosterone signal that drives inflammation and scarring in the kidney.
- The difference from spironolactone is fundamental. Spironolactone is steroidal and also binds sex-hormone receptors, hence gynaecomastia in men and menstrual disturbance in women. Finerenone is built differently and does not produce those effects.
- Indication: chronic kidney disease associated with type 2 diabetes. It works on top of standard therapy — an ACE inhibitor or ARB at the maximally tolerated dose — not instead of it.
- FIDELIO-DKD (NEJM, 2020): reduced risk of kidney disease progression — sustained decline in filtration, end-stage disease and renal death — versus placebo in 5,734 patients.
- FIGARO-DKD (NEJM, 2021): reduced cardiovascular events in 7,437 patients with diabetic kidney disease. The drug protects the heart as well as the kidney.
- The principal manageable risk is hyperkalaemia. Serum potassium is checked before initiation, four weeks after starting and at every dose change; treatment is paused if potassium runs high.
- Dosing depends on estimated GFR: with eGFR 25–60 mL/min/1.73 m² start at 10 mg daily, with eGFR 60 or above start at 20 mg; the target dose is 20 mg where potassium and tolerance allow.
- Do not start if potassium exceeds 5.0 mmol/L. Initiation is not recommended below an eGFR of 25 mL/min.
- Finerenone, SGLT2 inhibitors and renin-angiotensin blockers act through different mechanisms and complement each other in modern regimens rather than substituting for one another.
- This is not a general "kidney supplement": the indications are kidney disease in diabetes and, per the FDA label, heart failure with LVEF ≥40%; prescribing requires a confirmed diagnosis with assessment of albuminuria and filtration.
