A two-amino-acid peptide stored in muscle and brain, sold as a supplement and studied for blood sugar, memory and aging.
Also called L-carnosine, beta-alanyl-L-histidine, Zinc carnosine (related chelate), Polaprezinc (zinc-carnosine drug), N-acetylcarnosine (eye-drop form), Anserine/carnosine, Histidine-containing dipeptide
When Carnosine's status or evidence changes, it's in the next morning's email.
Carnosine is a dipeptide of beta-alanine and histidine. Your body makes it, mostly in skeletal muscle, and you also get it from meat. Inside muscle it soaks up acid during hard exercise. In the lab it also mops up reactive oxygen, binds metals and blocks sugars from sticking to proteins (glycation), which is why it is sold as an anti-aging supplement and appears in skin creams.
Swallowed carnosine is absorbed partly intact, but an enzyme in the blood, serum carnosinase, breaks it down within hours. In a 2025 study of 16 healthy volunteers, plasma levels peaked within an hour and little was left after 4 hours. Athletes who want more muscle carnosine usually take its building block, beta-alanine, instead: In a 24-week trial in 25 active men, 6.4 g of beta-alanine a day raised muscle carnosine compared with placebo.
The best human data are a handful of small trials in people with prediabetes or type 2 diabetes. In a 14-week trial in 43 adults, 2 g a day lowered blood sugar after a glucose drink, and an 8-trial meta-analysis that pooled carnosine and beta-alanine trials found modest drops in fasting glucose and HbA1c. None of these trials was large or long enough to show fewer cases of diabetes. Memory trials are mixed: in the same 14-week trial, carnosine alone did not change any cognitive score, while a carnosine plus anserine supplement helped on some scores in trials from one Japanese team. Carnosine itself is not an approved drug anywhere; a zinc-carnosine chelate, polaprezinc, is an ulcer drug in Japan.
What it binds to, and what happens inside the body after that, step by step.
Carnosine's histidine ring soaks up hydrogen ions, so muscle carnosine buffers the acid that builds up during intense exercise. In lab studies it also scavenges reactive oxygen, binds copper and zinc, and reacts with reactive sugars and aldehydes before they can damage proteins, which is the basis for the anti-glycation and anti-aging claims. Serum carnosinase splits circulating carnosine back into beta-alanine and histidine, so oral doses act briefly unless they are large.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
The A grade reflects the number of placebo-controlled trials, not strong proof of benefit: carnosine is not an approved drug, its trials are small (mostly 30 to 60 people for 8 to 14 weeks), and the results are mixed. The glucose results are modest, come largely from one Australian group, and a meta-analysis that found them pooled carnosine with beta-alanine. Carnosine alone did not improve cognition in a 2025 trial; the memory benefits come from a carnosine plus anserine supplement tested by one Japanese team.
8 placebo-controlled trials of carnosine or beta-alanine, 377 people with prediabetes or type 2 diabetes
Carnosine or beta-alanine lowered fasting glucose (standardized mean difference -0.53) and HbA1c (-0.36) versus placebo, with no change in BMI, fasting insulin or LDL cholesterol.
Read the study43 adults with prediabetes or type 2 diabetes, 2 g carnosine or placebo daily for 14 weeks
Blood glucose 2 hours into a glucose tolerance test was 1.60 mmol/L lower with carnosine; insulin levels and body composition did not change.
Read the study30 non-diabetic adults with overweight or obesity, 2 g carnosine or placebo daily for 12 weeks
Carnosine prevented the rise in fasting insulin and insulin resistance seen with placebo, and lowered 2-hour glucose in those with impaired glucose tolerance.
Read the study49 adults with prediabetes or early type 2 diabetes, 2 g carnosine or placebo daily for 14 weeks (a secondary analysis of the same trial as the 2024 glucose paper)
No difference from placebo on any cognitive test.
Read the study54 people with mild cognitive impairment in Japan, 750 mg anserine plus 250 mg carnosine or placebo daily for 12 weeks
Global Clinical Dementia Rating improved more than placebo (P=0.023), but MMSE, memory and ADAS scores did not, except in APOE4 carriers.
Read the study16 healthy volunteers, single doses escalating to 15 g; 4 took 5 g twice daily for 4 weeks
Doses up to 10 g were well tolerated; at 15 g, 77% had side effects, mostly headache, nausea and tingling. Plasma levels peaked within an hour and brain levels returned to baseline by 5 hours.
Read the study31 children with autism spectrum disorder, 800 mg a day or placebo for 8 weeks
Children on carnosine improved from their own baseline on the Gilliam Autism Rating Scale and a receptive vocabulary test while the placebo group did not; the abstract reports within-group changes, not a direct comparison with placebo, and the result has not been replicated at scale.
Read the studyNo preclinical studies are listed as key studies here. The human data above carries the evidence.
When a new Carnosine study in people is published, the daily email covers it.
These are questions the published research has not answered.
No product containing Carnosine is approved as a medicine by the FDA.
Carnosine is sold in the US as a dietary supplement and used in cosmetics; no regulator has approved carnosine itself as a drug. Polaprezinc (zinc L-carnosine, Promac), a chelate of zinc and carnosine developed by Hamari Chemicals and Zeria Pharmaceutical, was approved in Japan in 1994 as an anti-ulcer drug; it is a different compound from carnosine. N-acetylcarnosine eye drops are sold for cataracts, but a 2017 Cochrane review found no convincing evidence they work. Carnosine is not named on the WADA Prohibited List.
When the FDA or WADA changes Carnosine's status, it's in the next morning's email.
No human half-life has been published for Carnosine, so we do not draw a clearance curve. Half-lives quoted online for it are usually estimates from animal data.
This table records the doses that trials and approved labels used, with the source for each row. It is a record of research, not a recommendation, and it is open to free members.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
Lab and animal studies show anti-glycation and antioxidant effects, but no human trial has measured aging outcomes or lifespan.
Swallowed carnosine is broken down in the blood within hours. Athletes raise muscle carnosine with beta-alanine, which increased it in a 24-week trial in 25 active men.
A 2017 Cochrane review found no convincing evidence that N-acetylcarnosine drops reverse or slow cataract.
Small trials and a meta-analysis that pooled carnosine with beta-alanine show modest drops in fasting glucose and post-meal glucose in prediabetes and type 2 diabetes, but the trials are short and small.
Carnosine alone did not help cognition in a 49-person trial. A carnosine plus anserine supplement helped some memory scores in Japanese trials, all from one research team, and a 2026 meta-analysis rated that evidence low strength.
These pairings come up often. Almost none have been tested together in a trial, and the evidence note on each says so plainly.
Anserine is a methylated relative of carnosine found in chicken and fish; Japanese supplements combine them for memory in older adults.
EvidenceThree small RCTs from one Japanese team found benefits on some memory scores; a 2026 meta-analysis rated the evidence low strength.
Carnosine is added to creams as an antioxidant and anti-glycation ingredient, sometimes with eye-area peptides such as acetyl tetrapeptide-5.
EvidenceOnly cell studies support this pairing; a 2021 fibroblast study tested a mix including both. No human trial exists.
Supplement powders and capsules are stored dry at room temperature per the package.
Not applicable for oral supplements. Follow the package for cosmetic products.
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