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approvedCardiovascular

B-type Natriuretic Peptide (BNP)

Also known as: Brain Natriuretic Peptide, BNP, BNP-32, Natriuretic Peptide B

B-type Natriuretic Peptide (BNP) is a 32-amino acid endogenous cardiac hormone secreted primarily by ventricular cardiomyocytes in response to myocardial wall stress from volume overload or pressure overload. BNP promotes natriuresis, diuresis, and vasodilation while inhibiting the renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system. It is one of the most important biomarkers in modern cardiology, with plasma BNP and NT-proBNP levels used globally to diagnose and monitor heart failure.

4 cited references·5 researched benefits

Quick Answer

B-type Natriuretic Peptide (BNP) is a 32-amino acid cardiac hormone released by ventricular heart muscle cells under stress. It promotes salt and water excretion, relaxes blood vessels, and counteracts the renin-angiotensin system. Clinically, BNP blood levels serve as a critical biomarker for diagnosing and monitoring heart failure severity, with FDA-approved assays used in emergency departments worldwide.

Key Facts

Mechanism
BNP is synthesized as a 134-amino acid preprohormone (preproBNP) in ventricular cardiomyocytes. Cleavage produces the biologically active 32-amino acid BNP and the inactive 76-amino acid N-terminal fragment (NT-proBNP). BNP binds the natriuretic peptide receptor A (NPR-A), activating membrane-bound guanylate cyclase to increase intracellular cyclic GMP (cGMP). This triggers vasodilation, natriuresis, diuresis, suppression of renin and aldosterone secretion, inhibition of cardiac fibrosis, and reduction of sympathetic tone. BNP is cleared by NPR-C receptor-mediated internalization and neutral endopeptidase (neprilysin) degradation.
Research Status
approved
Half-Life
~20 minutes
Molecular Formula
C₁₄₃H₂₄₄N₅₀O₄₂S₄
Primary Use
Cardiovascular
Table of Contents

Benefits

  • Gold-standard biomarker for heart failure diagnosis — BNP >100 pg/mL highly sensitive for acute decompensated heart failurestrong
  • Prognostic value — serial BNP measurements predict heart failure outcomes and guide treatment intensitystrong
  • Differentiates cardiac from pulmonary causes of dyspnea in emergency settingsstrong
  • Natriuretic and diuretic effects reduce fluid overload and cardiac preloadstrong
  • Anti-fibrotic and anti-hypertrophic effects on cardiac tissue in preclinical modelsmoderate

Dosage Protocols

RouteDosage RangeFrequencyNotes
Diagnostic (blood test)BNP <100 pg/mL: heart failure unlikely; 100-400 pg/mL: possible heart failure; >400 pg/mL: heart failure likelyAs clinically indicatedCut-off values vary by assay. NT-proBNP uses higher thresholds (age-adjusted). Obesity lowers BNP levels; renal impairment raises them.
Intravenous infusion (as nesiritide/Natrecor)2 mcg/kg bolus followed by 0.01 mcg/kg/min continuous infusionContinuous IV infusion for up to 48 hoursRecombinant human BNP (nesiritide) FDA-approved for acute decompensated heart failure. See nesiritide profile for details.

Medical disclaimer

Dosage information is provided for educational reference only. Always follow your prescriber's instructions and consult a qualified healthcare provider before starting any peptide protocol.

Side Effects

  • Hypotension when administered exogenously (as nesiritide)common
  • Headache during exogenous infusioncommon
  • Renal impairment at high exogenous dosesserious
  • Nausea during intravenous administrationcommon

Frequently Asked Questions

What is the difference between BNP and NT-proBNP?
BNP and NT-proBNP are both released when proBNP is cleaved in cardiomyocytes. BNP is the biologically active 32-amino acid hormone with a half-life of about 20 minutes, while NT-proBNP is the inactive 76-amino acid N-terminal fragment with a longer half-life of approximately 120 minutes. Both are used as heart failure biomarkers, but they use different assays and cut-off values. NT-proBNP levels are generally higher and more affected by renal function and age. Your cardiologist will interpret results based on the specific assay used.
What BNP level indicates heart failure?
For BNP, levels below 100 pg/mL make heart failure unlikely (negative predictive value >90%). Levels between 100 and 400 pg/mL suggest possible heart failure requiring further evaluation. Levels above 400 pg/mL strongly suggest acute decompensated heart failure. For NT-proBNP, age-stratified cut-offs apply: <300 pg/mL rules out acute HF; >450 pg/mL (age <50), >900 pg/mL (age 50-75), or >1800 pg/mL (age >75) indicate likely HF. Always interpret in clinical context with your physician.
Can BNP levels be affected by factors other than heart failure?
Yes. BNP levels are influenced by several non-cardiac factors. Obesity lowers BNP levels (adipose tissue expresses more neprilysin, which degrades BNP), potentially causing false negatives. Renal impairment raises BNP due to reduced clearance. Atrial fibrillation, pulmonary embolism, sepsis, advanced age, and female sex all increase BNP independent of heart failure. Flash pulmonary edema may present with transiently low BNP if blood is drawn before levels peak (which takes several hours).
Is BNP used as a treatment or only as a diagnostic?
BNP serves primarily as a diagnostic biomarker. However, recombinant human BNP (nesiritide, brand name Natrecor) was FDA-approved in 2001 for intravenous treatment of acute decompensated heart failure. Nesiritide reduces pulmonary capillary wedge pressure and improves dyspnea but did not reduce mortality in the large ASCEND-HF trial. Its therapeutic use has declined substantially. Additionally, the drug sacubitril/valsartan (Entresto) works by inhibiting neprilysin to raise endogenous BNP levels in chronic heart failure.
How does the drug Entresto relate to BNP?
Entresto (sacubitril/valsartan) is a combination drug containing an angiotensin receptor blocker (valsartan) and a neprilysin inhibitor (sacubitril). Neprilysin is the enzyme that degrades endogenous BNP and ANP. By blocking neprilysin, sacubitril raises circulating levels of these natriuretic peptides, enhancing their beneficial vasodilatory, natriuretic, and anti-fibrotic effects. The PARADIGM-HF trial demonstrated 20% mortality reduction versus enalapril in heart failure with reduced ejection fraction, making Entresto a first-line treatment.

References

  1. 1
    Rapid measurement of B-type natriuretic peptide in the emergency diagnosis of heart failure(2002)PubMed ↗
  2. 2
    Intravenous nesiritide vs nitroglycerin for treatment of decompensated congestive heart failure (VMAC trial)(2002)PubMed ↗
  3. 3
    N-terminal pro-B-type natriuretic peptide in the emergency department: the ICON study(2006)PubMed ↗
  4. 4
    Angiotensin–neprilysin inhibition versus enalapril in heart failure (PARADIGM-HF)(2014)PubMed ↗

Latest Research

Last updated: 2026-02-19