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The muscle dipeptide with an unusual β-alanine — real physiology, a supplement market, and a research literature of over 3,000 papers.
Also known as: beta-alanyl-L-histidine
Part of the Foundational & therapeutic peptides cluster
Overview
Carnosine (β-alanyl-L-histidine) is a dipeptide concentrated in skeletal muscle and brain. Its imidazole ring buffers protons during intense exercise, and it scavenges reactive carbonyls and chelates metals; muscle carnosine can be raised by β-alanine supplementation. It is sold as a dietary supplement and studied in exercise, kidney, brain and lung biology; no carnosine product is an approved drug in the US, Canada or the EU.
Source & context
Biological / chemical source: Synthesized in muscle and brain from beta-alanine and histidine
Primary research or clinical context: Endogenous dipeptide sold as a dietary supplement; not an approved drug in North America or the EU; a zinc–carnosine complex is studied for gastric conditions
What carnosine is
Carnosine is β-alanyl-L-histidine, a dipeptide first discovered in skeletal muscle, where it exists in larger amounts than in any other tissue (Artioli et al., European Journal of Sport Science 2019). Its N-terminal residue is β-alanine, whose amino group sits on the β-carbon rather than the α-carbon, which makes carnosine resistant to ordinary peptidases and gives it an unusual place in peptide chemistry. It is synthesised in muscle and brain, catalogued by IUPHAR as a metabolite, and sold over the counter as a supplement. With more than 3,000 PubMed entries it is by far the best-studied molecule on this site that is not a drug.
Physiology: buffering, carbonyls and metals
The histidine imidazole has a pKa near physiological pH, so carnosine acts as an intracellular proton buffer in fast-twitch muscle where acidity rises during intense activity. It also scavenges reactive carbonyl species and chelates transition metals, mechanisms invoked for its reported effects outside muscle (Artioli et al., 2019). Proposed anti-ageing mechanisms include inhibition of the mechanistic target of rapamycin (mTOR) and carbonyl scavenging (Hipkiss et al., Maturitas 2016). Muscle carnosine content can be increased by supplementation, which is why β-alanine is a common sports supplement and why a large ergogenic literature exists.
Beyond muscle: brain, kidney, lung, bone
More recent work points to effects in other tissues, including brain, heart, pancreas, kidney and cancer cells (Artioli et al., 2019). Reviews cover carnosine and diabetic nephropathy (Peters et al., Current Medicinal Chemistry 2020), kidney disease more broadly, where serum carnosinase activity and genetic variants matter (Kiliś-Pstrusińska, Current Medicinal Chemistry 2020), lung disease (Tanaka and Kawahara, Current Medicinal Chemistry 2020), zinc–carnosine in neurodegeneration (Kawahara et al., Nutrients 2018) and bone (Yang et al., Molecular Medicine Reports 2023). Anti-ischaemic activity was reviewed as early as 2000 (Stvolinsky and Dobrota, Biochemistry (Moscow)). In a 2024 mouse study, exercise-derived carnosine protected haematopoietic stem cells after radiation via a Slc15a2–p53 axis (Zeng et al., Cell Communication and Signaling).
| Area | Focus | Representative source |
|---|---|---|
| Exercise physiology | Muscle buffering; β-alanine raises muscle carnosine | Artioli et al., 2019 |
| Ageing | mTOR inhibition and carbonyl scavenging hypotheses | Hipkiss et al., 2016 |
| Kidney | Diabetic nephropathy; carnosinase genetics | Peters et al., 2020; Kiliś-Pstrusińska, 2020 |
| Brain / lung | Zinc–carnosine and neurodegeneration; lung disease | Kawahara et al., 2018; Tanaka & Kawahara, 2020 |
Human evidence
The human literature is large but uneven. The best-established effect is indirect: β-alanine supplementation raises muscle carnosine and has been studied extensively for exercise performance (Artioli et al., 2019). Fifty-three studies are registered on ClinicalTrials.gov, most involving zinc–carnosine complexes (polaprezinc, PepZinGI) for gastric and reflux conditions, or diet and muscle-fatigue studies in older adults. Reviews of kidney and metabolic outcomes describe promising but preliminary data (Peters et al., 2020; Kiliś-Pstrusińska, 2020). No large randomised trial establishes a disease-modifying effect of oral carnosine itself in the sources reviewed.
Pharmacokinetics: the carnosinase problem
Orally ingested carnosine is largely hydrolysed by serum carnosinase (CNDP1) into β-alanine and histidine, which is why raising muscle carnosine is usually attempted with β-alanine rather than carnosine itself, and why individual carnosinase activity and genetic variants are a recurring theme in the kidney literature (Kiliś-Pstrusińska, 2020). A defined plasma half-life for intact carnosine is not stated in the abstracts reviewed; its persistence in muscle, where it is stored, is what matters physiologically.
Regulatory status as of September 2026
Carnosine is sold as a dietary supplement in the United States, Canada and the European Union and is not an approved drug in those markets. A zinc–carnosine complex appears in registered gastric trials. Carnosine also features in some grey-market “peptide” listings; unlike most of that market, the molecule itself is legal to sell as a supplement, so the question is evidence rather than legality.
Carnosine vs NAD+ and the longevity market
Carnosine is often sold next to NAD+ precursors and mitochondrial peptides on longevity menus. It is a genuine peptide — a dipeptide with a real peptide bond — whereas NAD+ is a coenzyme and MOTS-c is a mitochondrial-encoded peptide with a different biology. Its ageing hypotheses (mTOR, carbonyls) are mechanistic proposals reviewed in 2016, not trial results. The NAD+ explainer on this site covers the coenzyme; the MOTS-c and SS-31 profiles cover the mitochondrial peptides.
Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.
- Molecular form
- Dipeptide of β-alanine (amine on the β-carbon) and L-histidine; free termini
- Species
- Not established by this molecular identity audit
- Termini (N / C)
- Not specified / Not specified
Average reference mass
Reference policy updated: 2026-10-05
- IUPHAR/BPS source snapshot · 2026-10-01
- PubChem molecular record · 2026-10-01
- Molecular formula
- C9H14N4O3
- Average reference mass
- ≈ 226.23
- Receptors
- No receptor; acts as an intracellular proton buffer (imidazole pKa near physiological pH), carbonyl scavenger and metal chelator; hydrolysed by serum carnosinase (CNDP1)
- Backbone
- Dipeptide of β-alanine (amine on the β-carbon) and L-histidine; free termini
- Status
- Dietary supplement; endogenous metabolite (IUPHAR ligand 4559); 53 registered studies, mostly of zinc–carnosine or β-alanine (snapshot September 2026)
- PubChem CID: 439224
- IUPHAR ligand: 4559
- ChEMBL: CHEMBL242948
- CAS RN: 305-84-0
- UNII: 8HO6PVN24W
Chemistry values: curated profile, PubChem, IUPHAR/BPS Guide to Pharmacology · fetched 2026-10-01.
Clinical development snapshot
ClinicalTrials.gov lists 53 registered studies with “Carnosine” as an intervention (snapshot 2026-09-06). A registry footprint is not evidence of efficacy or approval.
| NCT | Title | Phase | Status | Updated |
|---|---|---|---|---|
| NCT07379645 | A Clinical Trial of PepZinGI® for Acute Heartburn Relief and Sleep Outcomes | Not applicable | completed | 2026-06-17 |
| NCT07590622 | EAT-ING: Enhancing Anticancer Treatment Safety Via Immunomodulatory Nutritional Support in Advanced Gastrointe | Not applicable | not yet recruiting | 2026-05-15 |
| NCT06678997 | Polaprezinc (Zinc L-carnosine) in Infants With Gastroesophageal Reflux | Not applicable | completed | 2026-05-05 |
| NCT05860088 | The Impact of Beef on Muscle Fatigue in Older Adults | Not applicable | completed | 2026-05-01 |
| NCT07475546 | Combination Gerotherapeutic Interventions for Healthspan Improvement | Phase 3 | active not recruiting | 2026-03-16 |
| NCT03314987 | Nucleophilic Defense Against PM Toxicity (NEAT Trial) | Not applicable | completed | 2026-01-06 |
Carnosine — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Dipeptide of β-alanine (amine on the β-carbon) and L-histidine; free terminiAverage reference mass: 226.23 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
Change log
Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.
- EditorialProfile content reviewed and updated by the editorial team.
FAQ about Carnosine
What is Carnosine?+
Carnosine (β-alanyl-L-histidine) is a dipeptide concentrated in skeletal muscle and brain. Its imidazole ring buffers protons during intense exercise, and it scavenges reactive carbonyls and chelates metals; muscle carnosine can be raised by β-alanine supplementation. It is sold as a dietary supplement and studied in exercise, kidney, brain and lung biology; no carnosine product is an approved drug in the US, Canada or the EU.
What Canadian product status is recorded for Carnosine?+
Canadian product status for Carnosine has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the typical length of Carnosine?+
Carnosine is commonly described as approximately 2 amino acids (Dipeptide).
What is carnosine?+
A dipeptide of β-alanine and L-histidine concentrated in skeletal muscle and brain. It buffers acid during intense exercise and scavenges reactive carbonyls and metals.
Is carnosine a peptide?+
Yes — a dipeptide with one peptide bond, although its β-alanine residue makes it resistant to ordinary peptidases.
Why do people take β-alanine instead of carnosine?+
Oral carnosine is largely broken down by serum carnosinase; β-alanine is the limiting precursor and raises muscle carnosine more efficiently.
Is carnosine approved as a drug?+
No. It is sold as a dietary supplement. A zinc–carnosine complex is studied in gastric conditions.
Does carnosine slow ageing?+
Mechanisms have been proposed (mTOR inhibition, carbonyl scavenging), but no human trial demonstrates an anti-ageing effect.
What is zinc carnosine?+
A chelate of zinc with carnosine (polaprezinc) studied for gastric and reflux conditions; it is a different product from carnosine alone.
Further reading
- PK conceptsWhy Peptides Have Short Half-Lives (And How Engineers Fix It)Proteases, renal clearance, DPP-4, PEGylation, lipidation, cyclization—educational guide to peptide pharmacokinetics concepts.
- Not a peptideIs NAD+ a Peptide? No — It Is a Coenzyme. What NAD+, NMN and NR Actually Are and What the Evidence Shows“NAD+ peptide” is a search term with no molecule behind it: NAD+ is a nucleotide coenzyme, not a peptide. This guide explains what NAD+ is, why it appears in peptide catalogues, what the precursors NMN and NR do, what human trials have and have not shown, and the regulatory status of each.
- FoundationsWhat Are Research Peptides? A Clear Educational GuideLearn what “research peptides” means, how they differ from approved peptide drugs, quality markers (COA, purity), and how to study them responsibly.
Related peptides
References & further reading
- 1.Boldyrev et al. (2013). Physiology and pathophysiology of carnosine. Physiol Rev
- 2.Yang et al. (2023). Carnosine and bone (Review). Mol Med Rep
- 3.Peters et al. (2020). Carnosine and Diabetic Nephropathy. Curr Med Chem
- 4.Greene et al. (1984). Enhanced carnosine (beta-alanyl-L-histidine) breakdown and histamine metabolism following treatment with compound 48/80. Eur J Pharmacol
- 5.Artioli et al. (2019). Carnosine in health and disease. Eur J Sport Sci
- 6.Margolis et al. (1977). Axoplasmic transport of carnosine (β-alanyl-L-histidine) in the mouse olfactory pathway. Neurochem Res
- 7.Tanaka et al. (2020). Carnosine and Lung Disease. Curr Med Chem
- 8.Blancquaert et al. (2017). Effects of Histidine and β-alanine Supplementation on Human Muscle Carnosine Storage. Med Sci Sports Exerc
- 9.Hipkiss et al. (2016). Carnosine and the processes of ageing. Maturitas
- 10.Kiliś-Pstrusińska (2020). Carnosine and kidney diseases: what we currently know? Current Medicinal Chemistry
- 11.Kawahara et al. (2018). Zinc, carnosine, and neurodegenerative diseases. Nutrients
- 12.PubChem — Carnosine, CID 439224