{"id":"carnosine","name":"Carnosine","aliases":["L-carnosine","beta-alanyl-L-histidine","β-alanine (precursor)"],"url":"https://lyoresearch.com/compounds/carnosine","class":{"id":"supplement-peptides","name":"Peptides sold as supplements","url":"https://lyoresearch.com/classes/supplement-peptides"},"summary":"Carnosine is a dipeptide of beta-alanine and histidine concentrated in muscle and brain, sold as a supplement for glucose control, ageing and exercise. A 2025 meta-analysis of eight randomised trials in 377 people with prediabetes or type 2 diabetes found modest reductions in fasting glucose and HbA1c against placebo, with no effect on weight or insulin resistance. The trials are small and short, and oral carnosine is largely broken down in blood before it reaches tissue. It is a food supplement, not a medicine.","overall_grade":"C","overall_grade_meaning":"weak human evidence","human_trials":"8 small RCTs (n=377) in a meta-analysis","regulatory_status":"Food supplement","molecule":{"formula":"C9H14N4O3","molecular_weight":"226.23","cas":"305-84-0","pubchem_cid":439224,"note":null},"pharmacokinetics":{"basis":"none","route":"Oral","half_life":"No half-life figure recorded by LYO; carnosine is hydrolysed in blood by serum carnosinase, which is why plasma levels are hard to sustain","licensed_regimen":null,"product":null,"source":null},"outcomes":[{"outcome":"Blood glucose (fasting glucose and HbA1c) in prediabetes and type 2 diabetes","grade":"C","grade_meaning":"weak human evidence","effect_size":"small","adverse":false,"human_studies":"8 RCTs (n=377) pooled","evidence":"Standardised mean differences of about half a standard deviation for fasting glucose and a third for HbA1c against placebo. Trials of 12–14 weeks; several at high risk of bias.","references":[{"citation":"Li N, et al. Effect of carnosine or beta-alanine supplementation therapy for prediabetes or type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials.","where":"BMC Endocr Disord, 2025","url":"https://pubmed.ncbi.nlm.nih.gov/40999397/"}],"verbatim":{"text":"Our analysis indicated that supplementation significantly reduced fasting blood glucose (FBG) (SMD: -0.53; 95% CI: -0.75 to -0.31; p < 0.00001) and hemoglobin A1c (HbA1c) levels (SMD:-0.36; 95% CI:-0.59 to -0.12; p = 0.003) compared to placebo.","citation":"Li N, et al. Effect of carnosine or beta-alanine supplementation therapy for prediabetes or type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials.","url":"https://pubmed.ncbi.nlm.nih.gov/40999397/"}},{"outcome":"Body weight and insulin resistance","grade":"C","grade_meaning":"weak human evidence","effect_size":"not measurable","adverse":false,"human_studies":"Same meta-analysis","evidence":"No effect on BMI, fasting insulin or HOMA-IR; a small fall in total cholesterol.","references":[{"citation":"Li N, et al. Effect of carnosine or beta-alanine supplementation therapy for prediabetes or type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials.","where":"BMC Endocr Disord, 2025","url":"https://pubmed.ncbi.nlm.nih.gov/40999397/"}],"verbatim":{"text":"No significant effects were observed on body mass index (BMI), fasting insulin. low-density lipoprotein cholesterol (LDL-c) or high-density lipoprotein cholesterol (HDL-c), but a lowering effect was observed in total cholesterol (TC).","citation":"Li N, et al. Effect of carnosine or beta-alanine supplementation therapy for prediabetes or type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials.","url":"https://pubmed.ncbi.nlm.nih.gov/40999397/"}},{"outcome":"Cognition or ageing","grade":"D","grade_meaning":"no human evidence","effect_size":"not measurable","adverse":false,"human_studies":"No adequate trial","evidence":"The anti-ageing use rests on animal and cell work on glycation and oxidative stress; no controlled human trial of an ageing endpoint exists.","references":[{"citation":"PubMed search: carnosine supplementation randomized trial cognition OR aging — no adequately powered trial of an ageing endpoint identified.","where":"PubMed, searched 2026-09-23","url":"https://pubmed.ncbi.nlm.nih.gov/?term=carnosine+supplementation+randomized+cognition"}]}],"regions":[{"region":"European Union","status":"Food supplement","note":"Sold as food; no authorised health claim."},{"region":"United States","status":"Dietary supplement","note":"Sold under DSHEA."},{"region":"United Kingdom","status":"Food supplement","note":"Food law."},{"region":"Australia","status":"Listed complementary medicine or food","note":"Depending on presentation."},{"region":"Canada","status":"Natural health product","note":"NPN products exist."},{"region":"Sport (WADA)","status":"Not prohibited","note":"Not on the Prohibited List; beta-alanine is likewise permitted."}],"faq":[{"q":"Does carnosine lower blood sugar?","a":"Modestly, in eight small trials pooled together — about a third of a standard deviation in HbA1c. Not a treatment for diabetes; possibly a small adjunct, if larger trials agree."},{"q":"Is carnosine the same as carnitine?","a":"No. Carnitine is an amino-acid derivative involved in fat transport; carnosine is a dipeptide. The names get confused constantly."},{"q":"Is carnosine a peptide?","a":"Yes — the simplest kind, two amino acids: beta-alanine and histidine."}],"references":[{"cite":"Li N, et al. Effect of carnosine or beta-alanine supplementation therapy for prediabetes or type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials.","where":"BMC Endocr Disord, 2025","url":"https://pubmed.ncbi.nlm.nih.gov/40999397/","note":"8 trials, 377 participants."},{"cite":"PubMed search: carnosine supplementation randomized trial cognition OR aging — no adequately powered trial of an ageing endpoint identified.","where":"PubMed, searched 2026-09-23","url":"https://pubmed.ncbi.nlm.nih.gov/?term=carnosine+supplementation+randomized+cognition"}],"last_reviewed":"2026-09-23","literature_searched_to":"2026-09-23","changelog":[{"date":"2026-09-23","note":"Initial publication. Grade C on the 2025 meta-analysis."}],"license":"CC BY 4.0 — cite as “LYO Research” with a link.","methodology":"https://lyoresearch.com/methodology"}