C-Type Natriuretic Peptide
Also known as: CNP, CNP-22, CNP-53, NPPC gene product, natriuretic peptide C-type, vosoritide (BMN-111, synthetic analog), navepegritide (TransCon CNP, prodrug analog), C-natriuretic peptide
Endogenous natriuretic peptide; paracrine/autocrine vascular and skeletal regulatory peptide; guanylyl cyclase-B (GC-B / NPR2) agonist
What it is
C-type natriuretic peptide (CNP) is used in children with achondroplasia to improve bone growth, and is under investigation for heart failure with preserved ejection fraction, pulmonary arterial hypertension, and fertility applications. It is an endogenous vascular peptide that doctors and researchers are working to harness therapeutically through synthetic analogs.
The scientific side
C-type natriuretic peptide (CNP) is a 22- or 53-amino acid peptide encoded by the NPPC gene, predominantly produced by vascular endothelial cells and chondrocytes rather than the heart. Its primary signaling receptor is guanylyl cyclase-B (GC-B, also termed NPR2), a transmembrane receptor that upon CNP binding generates cyclic guanosine monophosphate (cGMP) intracellularly. This CNP–NPR2–cGMP axis drives downstream phosphorylation cascades through cGMP-dependent protein kinase I (cGKI), producing broad paracrine effects across multiple tissues. In the skeletal system, CNP acts as the principal endogenous inhibitor of fibroblast growth factor receptor 3 (FGFR3) gain-of-function signaling; the FGFR3 gain-of-function mutation responsible for achondroplasia suppresses chondrocyte proliferation and endochondral ossification, and exogenous CNP or its analogs restore growth plate activity by counteracting FGFR3-mediated ERK and STAT1 phosphorylation, thereby increasing annualized growth velocity in affected children (PMIDs: 42306228, 42028063, 42077444). In the cardiovascular system, endothelial CNP released locally suppresses vascular smooth muscle proliferation, reduces arterial stiffness, inhibits pro-inflammatory cytokines (IL-6, CCL2, TGF-β1, endothelin-1), and maintains SMAD2/3-to-SMAD1/5/9 signaling balance. Endothelial-specific conditional knockout studies demonstrate that loss of CNP or NPR2 in pulmonary endothelial cells accelerates the development of pulmonary arterial hypertension (PAH), and exogenous CNP administration prevents and partially reverses PAH in murine models including Sugen5416-hypoxia models. In the nervous system, the CNP–NPR2–cGMP–cGKI axis regulates axon bifurcation in dorsal root ganglion neurons by reducing growth cone stiffness via F-actin depolymerization and suppressing ATP-induced calcium transients, suggesting a role in peripheral sensory circuit formation. In reproduction, CNP secreted by mural granulosa cells into follicular fluid maintains oocyte meiotic arrest by sustaining cGMP levels within the oocyte via gap-junction transfer, a function exploited in capacitation in vitro maturation (CAPA-IVM) protocols (PMIDs: 42632963, 42419071). A clearance receptor, NPR-C, binds CNP and internalizes it for degradation; in metabolic syndrome, upregulation of NPR-C in adipose tissue creates a functional CNP deficiency that contributes to cardiometabolic disease progression.
Class: Endogenous natriuretic peptide; paracrine/autocrine vascular and skeletal regulatory peptide; guanylyl cyclase-B (GC-B / NPR2) agonist
Administration & storage
- Administration
- Subcutaneous injection of vosoritide into the abdomenthighor upper arm — site rotation at each daily injection is recommendedSubcutaneous injection of navepegritide once weekly into abdomenthighor upper armVosoritide can be self-administered by caregivers or older patients after appropriate trainingInjection site reactions (erythemapain) are the most commonly reported local adverse effect; low isoelectric point CNP analogs (navepegritide) were engineered specifically to reduce injection site reactions vs. high-pI analogs (PMID: 41378963)
- Storage
- Vosoritide: unreconstituted vials should be refrigerated at 2–8°C (36–46°F). After reconstitution, use within 8 hours; do not freeze reconstituted solution. Navepegritide: store per manufacturer prescribing information (refrigerated). Endogenous CNP peptide used in research: store lyophilized at -20°C; reconstituted solutions should be used immediately or aliquoted and stored at -80°C to prevent degradation by neutral endopeptidases.
- Cautions
- Hypotension: CNP and CNP analogs are vasodilatory; blood pressure should be monitored before and after initiation of therapy, particularly in children with pre-existing cardiovascular conditions. Transient decreases in blood pressure have been reported in clinical trials of vosoritide.,Injection site reactions: the most common adverse events in vosoritide phase 3 trials were injection site erythema, bruising, and pain, reported in the majority of treated patients. Modified peptide design (low pI, fatty acid derivatization) reduces but does not eliminate ISRs. Site rotation is essential.,Growth plate considerations: CNP analogs must only be used while epiphyses remain open. Use after growth plate closure would provide no skeletal benefit and the long-term systemic effects of sustained GC-B agonism in adults are not fully characterized.,Cardiovascular monitoring: given CNP's role in vascular tone, heart rate, and blood pressure regulation, patients with cardiac comorbidities initiating CNP analog therapy require cardiovascular monitoring. CNP analogs under investigation for HFpEF and PAH are in early clinical phases; safety profiles in those populations are not yet established.,Drug interactions: CNP analogs may potentiate the hypotensive effects of antihypertensive agents, phosphodiesterase-5 inhibitors, and nitric oxide donors through additive cGMP pathway activation. Co-administration requires caution.,Renal and hepatic function: CNP is cleared partly by NPR-C receptor-mediated internalization and partly by neutral endopeptidase (neprilysin) degradation. Neprilysin inhibitors (e.g., sacubitril) could theoretically prolong endogenous CNP half-life; interaction with exogenous CNP analogs has not been formally studied.
Legal & regulatory status
CNP itself has no FDA approval for human therapeutic use. However, the synthetic CNP analog vosoritide (Voxzogo; BioMarin Pharmaceutical) received FDA approval in November 2021 for increasing linear growth in pediatric…
CNP and its synthetic analogs (vosoritide, navepegritide) are not explicitly listed on the WADA Prohibited List as of the 2024 List. However, growth-promoting peptide hormones and related substances are regulated under…
CNP itself is not approved as a therapeutic agent in Canada. Vosoritide (Voxzogo) received Health Canada approval for achondroplasia, consistent with its FDA and EMA approvals for this rare skeletal dysplasia.…
What it's studied for
- Achondroplasia — increasing linear growth velocity in children (vosoritide, synthetic CNP analog) Phase III RCT
- Achondroplasia — improving spinal morphology and preventing spinal stenosis complications Phase II RCT
- Hypochondroplasia — linear growth improvement (vosoritide, phase 3 trial underway) Phase III RCT
- Heart failure with preserved ejection fraction (HFpEF) — CNP analog therapy (early clinical investigation) Translational / Early Clinical
- Pulmonary arterial hypertension (PAH) — endothelial CNP/GC-B signaling as therapeutic target Preclinical (Animal)
- Fertility and assisted reproduction — oocyte meiotic arrest maintenance in IVM protocols (CAPA-IVM) Human observational
- Aortic valve disease — endogenous CNP as a biomechanically regulated protective factor Mechanistic only
- Cardiometabolic disease, hypertension, and obesity — CNP deficiency and NPR-C pathway as therapeutic target Mechanistic only
- Brugada Syndrome — exosomal CNP as molecular biomarker Human observational
Safety signals
- Injection site reactions (erythema, pain, bruising)
- Transient hypotension and blood pressure decreases
- Potential for off-target growth stimulation if misused outside achondroplasia
- Exosomal and circulating CNP alterations in cardiac arrhythmia (Brugada Syndrome)
- Neutral endopeptidase (neprilysin) degradation and short endogenous half-life — relevant to dosing and drug interactions
- Reproductive biology effects — CNP alters oocyte maturation, follicular steroidogenesis, and embryo development
- CNP deficiency in cardiometabolic syndrome — risk of adverse remodeling
All studies (4)
Frequently asked
What is CNP and how is it different from BNP or ANP?
CNP (C-type natriuretic peptide) is one of three related natriuretic peptides, but it works differently from its relatives ANP (atrial natriuretic peptide) and BNP (B-type natriuretic peptide). While ANP and BNP are released by the heart in response to pressure or volume overload and act systemically to lower blood pressure and promote salt excretion, CNP is produced primarily by vascular endothelial cells and chondrocytes (cartilage cells). CNP acts locally — in the blood vessel wall, growth plate, nervous system, and reproductive organs — through a different receptor called GC-B (NPR2), rather than the NPR1 receptor used by ANP and BNP. This distinct localization and receptor specificity means CNP can be targeted therapeutically without disrupting the cardiac natriuretic peptide system.
Is vosoritide the same thing as CNP?
Vosoritide (brand name Voxzogo) is a synthetic analog of CNP — it is engineered to mimic CNP's actions at the GC-B receptor but with a longer half-life suitable for once-daily subcutaneous injection. Native CNP has a plasma half-life of only about 2–3 minutes because it is rapidly broken down by an enzyme called neprilysin. Vosoritide includes structural modifications (a C-terminal glycine extension and a Pro-Gly linker) that resist neprilysin degradation while preserving receptor binding. Similarly, navepegritide (YUVIWEL) is a longer-acting prodrug of CNP designed for once-weekly dosing. Neither vosoritide nor navepegritide is the same as naturally occurring CNP, but both act through the same CNP receptor pathway.
Can CNP or vosoritide be used by adults to grow taller?
No. Vosoritide and CNP analogs work specifically by counteracting overactive FGFR3 signaling at the growth plate. They are approved only for children with achondroplasia or related FGFR3 gain-of-function conditions who still have open growth plates. Once the growth plates close — which happens naturally by the end of adolescence — CNP analogs cannot stimulate further height growth, and using them in adults without a specific medical indication would carry cardiovascular risks (hypotension, blood pressure effects) without benefit. There is no published evidence supporting off-label CNP analog use for height augmentation in adults without achondroplasia or related conditions.
Is CNP being studied for heart failure?
Yes, CNP is an active area of research for heart failure — specifically heart failure with preserved ejection fraction (HFpEF) and pulmonary arterial hypertension (PAH). CNP's unique ability to reduce vascular stiffness, suppress inflammatory signaling, and improve endothelial function through the GC-B receptor makes it attractive for these conditions where existing therapies have limited efficacy. A once-weekly CNP analog has entered Phase 1 clinical trials for HFpEF, and animal studies show CNP prevents and partially reverses PAH. However, these indications remain investigational as of late 2026 and no CNP therapy is yet approved for any cardiovascular condition in adults.
What are the side effects of vosoritide treatment?
The most commonly reported side effects of vosoritide in clinical trials are at the injection site — redness, pain, bruising, and swelling — which affect the majority of treated children but are generally mild and manageable with injection site rotation. Transient decreases in blood pressure have also been observed, so blood pressure monitoring is standard at initiation. There is no evidence of serious cardiovascular events at therapeutic doses in pediatric achondroplasia trials. Because vosoritide must only be used while growth plates are open, long-term effects beyond the pediatric growth period are not fully characterized. Consulting a specialist prescriber familiar with achondroplasia management is essential.
Is CNP used in IVF or fertility treatments?
CNP is used in a specialized fertility technique called CAPA-IVM (capacitation in vitro maturation), which is an alternative to conventional IVF that avoids or reduces the need for ovarian hyperstimulation. In CAPA-IVM, immature eggs (oocytes) retrieved from unstimulated or minimally stimulated ovaries are briefly exposed to CNP during a pre-maturation phase. CNP maintains the oocyte in meiotic arrest — pausing its development — while the surrounding cumulus cells undergo important preparatory maturation steps. The oocyte is then moved to a standard maturation medium, improving the proportion that reach the correct stage for fertilization. CAPA-IVM is an emerging technique and is not yet the standard of care worldwide, but clinical use is expanding in specialist centers.