Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library

Carnosine (L-carnosine, β-alanyl-L-histidine): what the evidence says

Name: Carnosine (L-carnosine, β-alanyl-L-histidine)
Published: 2026-10-27

At a glance

What it is: a two-amino-acid peptide (beta-alanine + histidine) made in the body and concentrated in muscle and brain; sold as a dietary supplement. ^{R1, R2}

What the evidence says: 🟨 pooled small trials suggest modest drops in HbA1c and fasting glucose, but individual RCTs are mixed. ^{R3, R4, R5} Memory benefits are seen mainly with carnosine-anserine blends, and the evidence is rated low-strength. ^R6 A Cochrane review found no convincing evidence that N-acetylcarnosine eye drops reverse cataract. ^R7

Biggest risks: no serious harms reported in short trials, but long-term safety data are thin. Taken by mouth, carnosine is broken down quickly by a blood enzyme (serum carnosinase), so how much reaches tissues is unclear. ^R8

Rating


Human Human evidence	Limited: small RCTs and meta-analyses ^{R3, R4, R5, R6}
Animal Animal / lab evidence	Not reviewed
Regulatory	Not FDA-approved as a drug · L-carnosine in Category 3 on FDA's 503A and 503B bulk lists ^{R9, R10} · not on FDA's safety-risk page ^R11 · not named by WADA ^R12
Established human dose	No (supplement amounts vary by study; see Study details)

Evidence verdict: Blood sugar and metabolic health: Limited (small RCTs, mixed results) · Cognition: Very limited (mainly carnosine-anserine blends) · Cataract eye drops (N-acetylcarnosine): No convincing evidence

This page reports what studies used. It is not dosing advice.

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

About the evidence: the trials are small and short, used different products and mixes (some with anserine or beta-alanine), and measured mostly lab markers rather than health outcomes.

What is it?

Related pages: acetyl-tetrapeptide-5.

Does it work?

🟨 Blood sugar: a meta-analysis of 30 studies (23 pooled) linked higher carnosine intake to lower waist size and HbA1c. ^R3 A 2025 pooled analysis of 8 RCTs (377 people) found lower fasting glucose and HbA1c with carnosine or beta-alanine. ^R4
Human But a 14-week RCT in 49 adults with prediabetes or type 2 diabetes found no effect on blood vessel or metabolic measures. ^R5
🟨 Memory and thinking: a 2026 review of 13 studies rated the evidence low-strength; benefits appeared mainly with carnosine-anserine blends. ^{R6, R13}
Human Cataract: Cochrane found no convincing evidence for N-acetylcarnosine eye drops. ^R7

Is it safe?

Short trials reported no serious safety signals, but they were small. ^{R5, R13}
Oral carnosine is rapidly degraded by serum carnosinase. ^R8
Supplement products are not reviewed by FDA for purity or content before sale.

Gray-market vials: extra risks

A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.

Is it legal?

US: not an FDA-approved drug; no Drugs@FDA application found (openFDA searched Oct 27, 2026). It is sold as a dietary supplement.
Compounding: L-carnosine is listed in Category 3 (nominated without adequate support) on both FDA's 503A and 503B bulk-substance lists, and is not on FDA's compounding safety-risk page. ^{R9, R10, R11}
Sport: not named on WADA's 2026 Prohibited List. ^R12

Study details

These are amounts researchers used, not recommendations.

Study	People / model	Route	Amount used	Follow-up	Reported	Citation
Saadati 2023	49 adults, prediabetes or T2DM	Oral	2 g/day	14 weeks	No change in vascular or metabolic measures vs placebo	PMID 38004228
Hisatsune 2016	39 older adults	Oral	Anserine/carnosine blend, per study	3 months	Better delayed recall vs placebo	PMID 26682691
Menon 2020 meta-analysis	30 studies (23 pooled)	Oral (diet or supplement)	Varied	Varied	Waist −3.53 cm; HbA1c −0.76%	PMID 31828942
Li 2025 meta-analysis	8 RCTs, n = 377	Oral (carnosine or beta-alanine)	Varied	Varied	Lower fasting glucose and HbA1c	PMID 40999397
Cochrane 2017	N-acetylcarnosine eye drops	Eye drops	Per study	Varied	No convincing evidence on cataract	PMID 28245346

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)

^R1 PubChem CID 439224, Carnosine (C9H14N4O3), checked Oct 27, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/439224
^R2 Cesak O, et al. Nutrients. 2023. PMID 37049610
^R3 Menon K, et al. Obes Rev. 2020. PMID 31828942
^R4 Li N, et al. BMC Endocr Disord. 2025. PMID 40999397
^R5 Saadati S, et al. Nutrients. 2023. PMID 38004228
^R6 Hsiao YF, et al. Nutrients. 2026. PMID 42123986
^R7 Dubois VD, et al. Cochrane Database Syst Rev. 2017. PMID 28245346
^R8 Oppermann H, et al. Int J Mol Sci. 2021. PMID 34884603
^R9 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download L-Carnosine appears in Category 3.
^R10 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download L-Carnosine appears in Category 3.
^R11 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
^R12 WADA. The 2026 Prohibited List, full list checked; compound not named. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
^R13 Hisatsune T, et al. J Alzheimers Dis. 2016. PMID 26682691

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use Carnosine (L-carnosine, β-alanyl-L-histidine). This compound is not FDA-approved. Any product sold under this name in the US is unregulated. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).