ANP
The heart's own salt-excreting hormone, sold in Japan as carperitide and tested without success in US kidney trials
Atrial natriuretic peptide is a 28-amino-acid hormone the heart's atria release when they are stretched by volume or pressure. It makes the kidneys excrete salt and water, widens vessels and suppresses renin and aldosterone. Recombinant ANP, carperitide, has been sold in Japan for acute heart failure since 1995; it has never been approved in the US.
What is it?
The heart is an endocrine organ. Its atrial muscle stores a precursor that is released as active ANP, 28 amino acids long, when the atria are stretched by extra volume or pressure; levels also rise with lying down, exercise and age. Infused into people, ANP lowers blood pressure, shifts fluid out of the circulation, inhibits renin, aldosterone and cortisol, and increases salt and water excretion even at doses that keep levels in the natural range.
That profile made it a candidate for failing kidneys. In 504 critically ill patients with acute tubular necrosis, a 24-hour infusion of anaritide did not improve dialysis-free survival, 43% against 47% on placebo, though it seemed to help the 120 with low urine output. A follow-up trial in 222 such oliguric patients found no significant benefit, and a trial in 247 people to prevent contrast-dye kidney injury found none at any of three doses.
Later trials used much lower doses. Pooled, 18 small trials suggested low-dose ANP halves new kidney injury and reduces dialysis, but the authors judged them too small and biased to settle the question. A randomised trial in heart transplant recipients found no significant protection, and in critically ill patients overall mortality did not change.
Japan took a different path. Carperitide, recombinant human ANP, was launched there in 1995 for acute heart failure, and a Japanese trial in 367 high-risk heart bypass patients reported fewer major cardiovascular events and no new dialysis on low-dose carperitide. The heart failure evidence is mixed: registry data link low doses to lower one-year mortality, a trial of low-dose carperitide found no benefit, and a 2025 meta-analysis found higher in-hospital mortality overall but no difference in the randomised trials.
It has never been approved in the US. Its cousin BNP, made by the ventricles, has its own entry.
Mechanism of Action
ANP is a 28-amino-acid hormone released by stretched atria that promotes salt and water loss and lowers blood pressure.
Salt and water excretion
Increases sodium and water excretion by the kidneys, even at doses within the natural range.
Lower pressure, less volume
Lowers blood pressure and shifts fluid out of the circulation.
Hormone brake
Inhibits renin, aldosterone and cortisol.
Published Research
These are the studies that describe ANP as a treatment, read from their PubMed abstracts: four randomised trials and a review of its physiology in people.
Acute tubular necrosis
504 critically ill patients received a 24-hour anaritide infusion or placebo. Dialysis-free survival at 21 days was 43% against 47%; in 120 with low urine output it was 27% against 8%.
The follow-up in low urine output
222 patients with oliguric acute renal failure received anaritide or placebo. Dialysis-free survival was 21% against 15%, not significant, so the earlier subgroup finding was not confirmed.
Preventing contrast injury
247 people with chronic kidney disease received one of three anaritide doses or placebo around radiocontrast. Kidney injury rates were 19% on placebo and 23 to 25% on anaritide: no protection.
Carperitide in heart surgery
367 high-risk Japanese bypass patients received low-dose carperitide or placebo. Survival did not differ, but major cardiovascular events were fewer and no carperitide patient started dialysis, against 7 on placebo.
LASCAR-AHF: low-dose carperitide
In 247 Japanese patients with acute heart failure, low-dose carperitide for 72 hours did not reduce death or heart-failure admission over 2 years (29.5% against 28.0%).
Kidney injury after cardiac surgery
After cardiac surgery, low-dose ANP raised urine output in 77 patients with kidney injury but did not improve kidney function.
Heart transplantation
In 70 heart transplant recipients, an ANP infusion of 50 ng/kg/min for four days did not improve measured kidney function at day 4 or significantly reduce acute kidney injury (63.6% against 76.5%) or dialysis (9.1% against 21.6%).
Acute heart failure registry in Japan
Among 2,435 patients pooled from two Japanese registries, low-dose carperitide (0.02 µg/kg/min or more) was associated with lower one-year cardiovascular and all-cause mortality (hazard ratios 0.70 and 0.79) than no or very-low-dose carperitide.
Physiological doses and fat metabolism
In 10 healthy men, infusing ANP at levels seen during exercise did not change lipolysis, ketogenesis, glucose metabolism, blood volume or blood pressure.
ANP in people
Atrial stretch releases 28-amino-acid alpha-ANP; infused, it lowers blood pressure and plasma volume, inhibits renin, aldosterone and cortisol, and increases salt and water excretion at physiological doses.
Carperitide in acute heart failure: meta-analysis
Across four trials and five matched studies, in-hospital mortality was higher with carperitide overall (odds ratio 1.38) but not in the randomised trials alone; long-term mortality, rehospitalisation and hypotension did not differ.
Low-dose ANP for kidney injury
Across 18 trials, low-dose ANP halved new acute kidney injury in prevention trials (risk ratio 0.51) and reduced dialysis need, but the trials were too small and biased to be conclusive.
Critically ill patients
Pooled studies found no effect of ANP on mortality (risk ratio 1.03) but shorter hospital stays and better creatinine, with high heterogeneity.
Dosing Data
It is not approved in the US. In Japan carperitide is given as a continuous intravenous infusion; registries and recent trials used low doses, around 0.02 µg/kg/min.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
Side Effects & Contraindications
Reported Side Effects
From the infusion studies and trials above.
Contraindications & Cautions
Not a US medicine.
Legal Status
ANP is approved in Japan and not in the US.
Frequently Asked Questions
?What is ANP?
A 28-amino-acid hormone released by stretched heart atria that makes the kidneys excrete salt and water and widens vessels.
?Is it a medicine?
In Japan, as carperitide for acute heart failure since 1995. Not in the US.
?Does it protect the kidneys?
US trials of anaritide in acute kidney failure and contrast injury found no benefit.
?How is it different from BNP?
ANP comes mainly from the atria and BNP from the ventricles; both act on the same receptor family.
?Does carperitide help acute heart failure?
The evidence is mixed. Japanese registry data link low doses to lower one-year mortality, but a randomised trial of low-dose carperitide found no benefit, and a 2025 meta-analysis found higher in-hospital mortality overall with no difference in the randomised trials alone.
References
- [pubmed] Allgren RL, et al. "Anaritide in acute tubular necrosis. Auriculin Anaritide Acute Renal Failure Study Group." N Engl J Med, 1997;336(12):828-34. PMID: 9062091.
- [pubmed] Lewis J, et al. "Atrial natriuretic factor in oliguric acute renal failure. Anaritide Acute Renal Failure Study Group." Am J Kidney Dis, 2000;36(4):767-74. PMID: 11007679.
- [pubmed] Kurnik BR, et al. "Prospective study of atrial natriuretic peptide for the prevention of radiocontrast-induced nephropathy." Am J Kidney Dis, 1998;31(4):674-80. PMID: 9531185.
- [pubmed] Sezai A, et al. "Results of low-dose carperitide infusion in high-risk patients undergoing coronary artery bypass grafting." Ann Thorac Surg, 2013;96(1):119-26. PMID: 23702231.
- [pubmed] Weidmann P, et al. "Atrial natriuretic peptide in man." J Steroid Biochem, 1989;32(1B):229-41. PMID: 2521524.
- [pubmed] de Bold AJ, et al. "A rapid and potent natriuretic response to intravenous injection of atrial myocardial extract in rats." Life Sci, 1981;28(1):89-94. PMID: 7219045.
- [pubmed] Potter LR, et al. "Natriuretic peptides, their receptors, and cyclic guanosine monophosphate-dependent signaling functions." Endocr Rev, 2006;27(1):47-72. PMID: 16291870.
- [other] The Pharma Letter. Zeria Pharmaceuticals launches Hanp Injection (carperitide) in Japan for acute heart failure. May 28, 1995. Read September 30, 2026.
- [other] US FDA, Drugs@FDA (openFDA): no application for ANP, anaritide or carperitide. Read September 30, 2026.
- [clinical-trial] Honda S, et al. "Effect of low-dose administration of carperitide for acute heart failure: the LASCAR-AHF trial." Eur Heart J Acute Cardiovasc Care, 2025;14(2):83-92. PMID: 39656827.
- [clinical-trial] Mitaka C, et al. "Effects of low-dose atrial natriuretic peptide infusion on cardiac surgery-associated acute kidney injury: A multicenter randomized controlled trial." J Crit Care, 2017;38:253-258. PMID: 27997877.
- [pubmed] Tholén M, et al. "Atrial natriuretic peptide in the prevention of acute renal dysfunction after heart transplantation-a randomized placebo-controlled double-blind trial." Acta Anaesthesiol Scand, 2023;67(6):738-745. PMID: 36941798.
- [pubmed] Nogi K, et al. "Effect of carperitide on the 1 year prognosis of patients with acute decompensated heart failure." ESC Heart Fail, 2022;9(2):1061-1070. PMID: 35118813.
- [pubmed] Larsen EL, et al. "Effects of physiological doses of atrial natriuretic peptide on lipolysis, ketogenesis, and glucose metabolism in men." Am J Physiol Endocrinol Metab, 2025;329(4):E512-E521. PMID: 40857129.
- [pubmed] Shiga T, et al. "Effect of carperitide on clinical outcomes among patients with acute heart failure: a meta-analysis of randomized and propensity‑matched studies." BMC Cardiovasc Disord, 2025;25(1):896. PMID: 41310450.
- [pubmed] Yamada H, et al. "Low-dose atrial natriuretic peptide for prevention or treatment of acute kidney injury: a systematic review and meta-analysis." Crit Care, 2019;23(1):41. PMID: 30744687.
- [pubmed] Odutola PO, et al. "Effectiveness of Atrial Natriuretic Peptide in the Treatment of Critically Ill Patients: A Systematic Review and Meta-Analysis." J Clin Med, 2025;14(10). PMID: 40429263.
Sources & Citations
Studies were read from their PubMed abstracts; no US label exists. Read October 6, 2026.
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