Home Ingredients L-Carnosine (Beta-Alanyl-L-Histidine)
Metabolic Health

L-Carnosine (Beta-Alanyl-L-Histidine)

Evidence Level
Limited
5 Clinical Trials
6 Documented Benefits
2/5 Evidence Score

L-carnosine is a dipeptide made of beta-alanine and histidine that the body produces itself and stores mainly in muscle and brain. Supplement trials have used 1 to 2 g a day. Much of an oral dose is split apart in the blood by an enzyme called serum carnosinase, so blood levels rise only briefly. Its best-studied use is blood sugar: small placebo-controlled trials in adults with overweight, prediabetes or type 2 diabetes found lower post-glucose or fasting blood sugar, while blood pressure and thinking skills did not change in the trials that measured them, and cholesterol results were inconsistent. Other cognitive results are mixed, and in a large 12-week trial endurance tests mostly did not change. People who want more muscle carnosine for exercise usually take beta-alanine instead. Zinc-L-carnosine (polaprezinc) is a different product with its own page.

Studied Dose 2 g a day for 12 to 14 weeks in most trials; 1 g a day (500 mg twice daily) in one 12-week trial. Single doses up to 10 g were tolerated in a small safety study, while 15 g often caused headache or nausea.
Active Compound L-carnosine (beta-alanyl-L-histidine), a dipeptide of beta-alanine and L-histidine.

Benefits

Blood sugar response during a glucose tolerance test

In a 14-week trial of 43 adults with prediabetes or type 2 diabetes, 2 g a day of carnosine lowered blood sugar at 90 and 120 minutes of a glucose tolerance test compared with placebo, without changing insulin. A report on 49 similar adults from the same research group's 14-week trial found no change in blood pressure, blood vessel function or blood lipids.

Supported by Trial 1, Trial 2

Fasting glucose and HbA1c

In a 12-week trial of 54 adults with type 2 diabetes, 1 g a day of L-carnosine lowered fasting glucose by about 13 mg/dL and HbA1c (reported as 0.6%) compared with placebo, along with triglycerides. Fasting insulin and insulin-resistance scores did not change. It is one small single-center trial, and carnosine is not a substitute for diabetes care.

Supported by Trial 3

Insulin sensitivity markers in adults with overweight

In a 12-week pilot of 30 non-diabetic adults with overweight or obesity, fasting insulin and insulin resistance rose on placebo but not on 2 g a day of carnosine. Lower 2-hour glucose and insulin were seen only in the subgroup with impaired glucose tolerance. The trial was small, so these are early findings.

Supported by Trial 4

Glycemic markers in pooled trial data

Two meta-analyses pooled carnosine with its building block beta-alanine. One, with only 4 human studies, estimated lower HbA1c and insulin resistance; the other, with 8 trials in 377 people, found lower fasting glucose and HbA1c but no change in fasting insulin. Because the compounds were pooled and the trials were small, the effect of carnosine alone is uncertain.

Supported by Trial 4, Trial 3

Memory and thinking test scores

In a 12-week trial of 299 healthy adults, an after-the-fact analysis found 2 g a day improved overall cognitive speed and efficiency in people aged 23 to 35, with few or no gains in those aged 36 to 65. A 14-week trial in 49 adults found no change. A review rated the evidence low: gains in older adults came mainly from carnosine combined with anserine or antioxidants (see Anserine).

Supported by Trial 1, Trial 5

Muscle carnosine and exercise endurance

Four weeks of high-dose L-carnosine raised muscle carnosine about as much as 6.4 g a day of beta-alanine, most likely because it is broken down and releases beta-alanine. In a 12-week trial of 299 adults, 2 g a day did not change grip strength, gait speed or most endurance tests; only scattered subgroup gains were seen.

Supported by Trial 5

Mechanism of action

1

Broken down quickly by blood carnosinase

An enzyme in human blood, serum carnosinase, splits carnosine into beta-alanine and histidine. After a large single dose, only 8 of 25 healthy adults showed any rise in plasma carnosine, and they were the ones with less of the enzyme. In a dose study, plasma carnosine peaked within an hour and little remained after 4 hours.

2

Why beta-alanine is the usual route to muscle carnosine

Muscle builds its own carnosine from beta-alanine and histidine, and beta-alanine supply is the limiting step. Oral carnosine raises muscle carnosine mainly by releasing beta-alanine after breakdown. In one study the carnosine dose matched 6.4 g of beta-alanine molecule for molecule, which works out to roughly 16 g of carnosine a day, so beta-alanine is the more practical choice.

3

Builds up in red blood cells and binds reactive aldehydes

With 2 g a day for 12 weeks, red blood cell carnosine roughly doubled and urinary carnosine rose nearly sevenfold. Urine also showed more carnosine bound to propanal, a reactive product of fat oxidation, which fits laboratory evidence that carnosine traps such reactive compounds. Whether this changes health outcomes is not known.

Clinical trials

1
Carnosine and Glucose Tolerance in Prediabetes or Diabetes: 14-Week RCT
PubMed

Randomized, placebo-controlled trial of 2 g a day of carnosine for 14 weeks; the primary outcome was glucose metabolism on a 2-hour 75 g oral glucose tolerance test (Hariharan et al. 2024, Nutr Metab Cardiovasc Dis)

43 adults (30% women) with prediabetes or type 2 diabetes in Australia.

Compared with placebo, carnosine lowered blood glucose at 90 minutes (by 1.31 mmol/L) and 120 minutes (by 1.60 mmol/L) and lowered total glucose area under the curve. Insulin levels, body composition and calf muscle density did not change. The carnosine was donated by a manufacturer (Flamma Group) that had no role in the study.

2
Carnosine and Vascular Measures in Prediabetes or Diabetes: No Effect
PubMed

Double-blind randomized placebo-controlled trial of 2 g a day of carnosine for 14 weeks, reporting vascular and metabolic outcomes (Saadati et al. 2023, Nutrients)

49 adults with prediabetes or well-controlled type 2 diabetes.

No effect versus placebo on heart rate, blood pressure, endothelial function, arterial stiffness, blood lipids, liver scans, liver function tests or kidney measures. The authors concluded that carnosine is unlikely to be a useful way to lower cardiovascular risk in this group.

3
L-Carnosine 1 g a Day in Type 2 Diabetes: 12-Week RCT
PubMed

Double-blind, placebo-controlled randomized trial of two 500 mg L-carnosine capsules a day for 12 weeks (Houjeghani et al. 2018, Nutr Res)

54 adults with type 2 diabetes in Tabriz, Iran (27 per group).

Compared with placebo, fasting glucose fell by 13.1 mg/dL and HbA1c by a reported 0.6%, along with lower triglycerides, the glycation marker carboxymethyl lysine and TNF-alpha. Fasting insulin, HOMA insulin-resistance and secretion scores, cholesterol, blood pressure, IL-6 and IL-1 beta did not differ. Fat mass fell 1.5% and fat-free mass rose 1.7% versus placebo. A single-center trial.

4
Carnosine and Insulin in Adults With Overweight: 12-Week Pilot RCT
PubMed

Double-blind randomized pilot trial of 2 g a day of carnosine or placebo for 12 weeks, with oral glucose tolerance tests (de Courten et al. 2016, Obesity)

30 non-diabetic adults with overweight or obesity, average age 43 (15 per group).

Urinary carnosine rose with supplementation. Fasting insulin and insulin resistance rose on placebo, and that rise was blunted with carnosine (P = 0.02 and P = 0.04 after adjustment). Two-hour glucose and insulin were lower only in the subgroup with impaired glucose tolerance. A small pilot.

5
Carnosine and Physical Endurance in the NEAT Trial: Mostly No Effect
PubMed

Placebo-controlled randomized trial of 2 g a day of carnosine for about 12 weeks with repeated physical function tests (O'Toole et al. 2026, J Int Soc Sports Nutr)

299 adults randomized to carnosine or placebo.

Grip strength, gait speed and the other measures did not differ from placebo overall. In subgroup analyses, under-40s did more calf raises at 6 weeks (P = 0.018) and men over 40 took more steps on a 2-minute step test at 12 weeks (P = 0.010). These scattered subgroup results need confirmation.

Side effects and drug interactions

Common Potential side effects

In a 12-week trial of 2 g a day, no adverse reactions were reported and kidney, liver and heart function and blood electrolytes did not change.
Single doses up to 10 g were well tolerated in a small safety study, but at 15 g most participants (77%) had side effects, mainly headache, nausea and tingling of the skin.
Safety beyond about 14 weeks of daily use has not been studied in trials.
Pregnancy and breastfeeding: there are no safety data for supplemental doses, so ask a doctor before use.

Important Drug interactions

Diabetes medicines: carnosine lowered blood sugar in some small trials, so people taking glucose-lowering drugs should talk with their doctor and watch their readings. No interaction has been formally studied.
No drug interactions were reported in the studies cited on this page.

More Metabolic Health Ingredients

Metabolic Health
Psyllium Husk (Plantago ovata)
Psyllium husk is the seed coat of Plantago ovata, a gel-forming soluble fiber sold as a bu…
Metabolic Health
Thiamine
Thiamine, also known as vitamin B1, is a water-soluble vitamin essential for converting ca…
Metabolic Health
Magnesium
Magnesium is an essential mineral and a cofactor in more than 300 enzyme systems, includin…
Metabolic Health
Ginger (Zingiber officinale)
Ginger is a widely used culinary spice with a long history of traditional use. Its pungent…

Explore Other Ingredients

Athletic Performance
Senactiv®
Senactiv® (formerly ActiGin®) is a NuLiv Science ingredient made from purified fractions o…
Cardiovascular
Spirulina
Spirulina is a blue-green algae celebrated as a nutrient-dense superfood, packed with prot…
Athletic Performance
L-Carnitine
L-carnitine is a nutrient the body uses to carry long-chain fats into mitochondria, the ce…

Related articles from our blog

📝 Article
Supplements for Leaky Gut: What the Evidence Actually Shows
"Leaky gut" is one of the most marketed ideas in wellness, blamed for everything from bloating to brain fog to autoimmun…
July 5, 2026

Frequently asked questions about L-Carnosine (Beta-Alanyl-L-Histidine)

Is L-carnosine the same as zinc carnosine?

No. Zinc-L-carnosine (polaprezinc) is a chelate of zinc and carnosine that is studied for the stomach lining and is a prescription medicine in Japan. Plain L-carnosine contains no zinc and has been studied mainly for blood sugar, thinking skills and exercise. Each has its own page on this site.

Should I take L-carnosine or beta-alanine for exercise?

For raising muscle carnosine, beta-alanine is the usual choice. Carnosine taken by mouth is largely broken down in the blood to beta-alanine and histidine, so a much larger weight of carnosine is needed to supply the same beta-alanine. A 12-week trial of 2 g a day of carnosine found no change in most physical tests.

How much L-carnosine is used in studies?

Most trials used 2 g a day for 12 to 14 weeks, and one used 1 g a day. In a small safety study single doses up to 10 g were tolerated, while 15 g often caused headache and nausea.

Is L-carnosine safe?

In the trials that reported safety, 2 g a day for 12 to 14 weeks caused no reported adverse reactions and no changes in kidney or liver tests. Longer-term safety and use in pregnancy have not been studied. If you take medicine for blood sugar, check with your doctor first.

What is L-Carnosine?

L-carnosine is a dipeptide made of beta-alanine and histidine that the body produces itself and stores mainly in muscle and brain. Supplement trials have used 1 to 2 g a day. Much of an oral dose is split apart in the blood by an enzyme called serum carnosinase, so blood levels rise only briefly.

What is L-Carnosine used for?

L-Carnosine is researched primarily for Metabolic Health. In a 14-week trial of 43 adults with prediabetes or type 2 diabetes, 2 g a day of carnosine lowered blood sugar at 90 and 120 minutes of a glucose tolerance test compared with placebo, without changing insulin.

What is the recommended dosage of L-Carnosine?

The clinically studied dose is 2 g a day for 12 to 14 weeks in most trials; 1 g a day (500 mg twice daily) in one 12-week trial. Single doses up to 10 g were tolerated in a small safety study, while 15 g often caused headache or nausea. Always follow the product label and check with a healthcare provider for personal advice.

Is L-Carnosine safe, and does it have side effects?

For most healthy adults, L-Carnosine is well tolerated at studied doses. Reported effects can include: In a 12-week trial of 2 g a day, no adverse reactions were reported and kidney, liver and heart function and blood electrolytes did not change. It may also interact with some medications. L-Carnosine is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does L-Carnosine interact with any medications?

Possible interactions include: Diabetes medicines: carnosine lowered blood sugar in some small trials, so people taking glucose-lowering drugs should talk with their doctor and watch their readings. No interaction has been formally studied. No drug interactions were reported in the studies cited on this page. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for L-Carnosine?

NutraSmarts rates the evidence for L-Carnosine as Limited (2 out of 5). It is backed by 5 clinical trials and 16 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(16 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Hariharan R, Cameron J, Menon K, Mesinovic J, Jansons P, Scott D, Lu ZX, de Courten M, Feehan J, de Courten B. Carnosine supplementation improves glucose control in adults with pre-diabetes and type 2 diabetes: A randomised controlled trial. Nutr Metab Cardiovasc Dis. 2024;34(2):485-496. doi: 10.1016/j.numecd.2023.10.012.PubMedUsed to support: 14-week randomized placebo-controlled trial in 43 adults with prediabetes or type 2 diabetes. 2 g a day of carnosine lowered blood glucose at 90 minutes (by 1.31 mmol/L) and 120 minutes (by 1.60 mmol/L) of an oral glucose tolerance test and lowered total glucose area under the curve, with no change in insulin levels, body composition or calf muscle density. The carnosine was donated by Flamma Group, which had no role in the study.
  2. Saadati S, Cameron J, Menon K, Hodge A, Lu ZX, de Courten M, Feehan J, de Courten B. Carnosine Did Not Affect Vascular and Metabolic Outcomes in Patients with Prediabetes and Type 2 Diabetes: A 14-Week Randomized Controlled Trial. Nutrients. 2023;15(22):4835. doi: 10.3390/nu15224835.PubMedUsed to support: Double-blind randomized trial in 49 adults with prediabetes or well-controlled type 2 diabetes. 2 g a day of carnosine for 14 weeks had no effect versus placebo on heart rate, blood pressure, endothelial function, arterial stiffness, blood lipids, liver measures or kidney measures.
  3. Houjeghani S, Kheirouri S, Faraji E, Jafarabadi MA. l-Carnosine supplementation attenuated fasting glucose, triglycerides, advanced glycation end products, and tumor necrosis factor-α levels in patients with type 2 diabetes: a double-blind placebo-controlled randomized clinical trial. Nutr Res. 2018;49:96-106. doi: 10.1016/j.nutres.2017.11.003.PubMedUsed to support: Double-blind randomized trial in 54 adults with type 2 diabetes in Iran. 1 g a day of L-carnosine (two 500 mg capsules) for 12 weeks lowered fasting blood glucose (by 13.1 mg/dL), HbA1c (reported as 0.6%), triglycerides, the glycation marker carboxymethyl lysine and TNF-alpha versus placebo. Fat mass fell (by 1.5%) and fat-free mass rose (by 1.7%) versus placebo, and the glycation marker pentosidine fell within the carnosine group compared with baseline. Fasting insulin, HOMA insulin-resistance scores, cholesterol, blood pressure, IL-6 and IL-1 beta did not differ between groups.
  4. de Courten B, Jakubova M, de Courten MP, Kukurova IJ, Vallova S, Krumpolec P, Valkovic L, Kurdiova T, Garzon D, Barbaresi S, Teede HJ, Derave W, Krssak M, Aldini G, Ukropec J, Ukropcova B. Effects of carnosine supplementation on glucose metabolism: Pilot clinical trial. Obesity (Silver Spring). 2016;24(5):1027-34. doi: 10.1002/oby.21434.PubMedUsed to support: Double-blind randomized pilot trial in 30 non-diabetic adults with overweight or obesity (15 per group). 2 g a day of carnosine for 12 weeks raised urinary carnosine; the rise in fasting insulin and insulin resistance seen on placebo was blunted with carnosine, and in the subgroup with impaired glucose tolerance 2-hour glucose and insulin were lower than on placebo.
  5. Matthews JJ, Dolan E, Swinton PA, Santos L, Artioli GG, Turner MD, Elliott-Sale KJ, Sale C. Effect of Carnosine or β-Alanine Supplementation on Markers of Glycemic Control and Insulin Resistance in Humans and Animals: A Systematic Review and Meta-analysis. Adv Nutr. 2021;12(6):2216-2231. doi: 10.1093/advances/nmab087.PubMedUsed to support: Bayesian meta-analysis of 20 studies, only 4 of them in humans, pooling carnosine and beta-alanine. In humans supplementation was estimated to lower HbA1c (mean difference -0.91%, 90% credible interval -1.46 to -0.39), HOMA-IR and fasting insulin; the human fasting glucose estimate (-0.95 mmol/L) had an interval that crossed zero. Certainty for the human outcomes was rated moderate.
  6. Li N, Yan X, Lin J, Wu M, He X, Yang J, Li H, Wei W, Zhang Y, Zhong Y, Xu G, Fan Z, Hu X, Wang Y, Shi Z. 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. BMC Endocr Disord. 2025;25(1):210. doi: 10.1186/s12902-025-02016-w.PubMedUsed to support: Meta-analysis of 8 placebo-controlled trials (377 participants with prediabetes or type 2 diabetes) of carnosine or beta-alanine. Supplementation lowered fasting blood glucose (SMD -0.53), HbA1c (SMD -0.36) and total cholesterol (SMD -0.23, p = 0.04), and improved HOMA-beta, with no significant effect on BMI, fasting insulin, LDL or HDL cholesterol; HOMA-IR did not reach significance. The authors call for more rigorous trials.
  7. O'Toole TE, Amraotkar AR, Gao H, Sears CG, Rai SN, Basner M, Bhatnagar A. Carnosine supplementation improves cognitive outcomes in younger participants of the NEAT trial. Neurotherapeutics. 2025;22(2):e00541. doi: 10.1016/j.neurot.2025.e00541.PubMedUsed to support: Post-hoc secondary analysis of a placebo-controlled trial in which 299 adults were randomized to 2 g a day of carnosine or placebo for up to 12 weeks (231 to 242 analyzed). On a 10-test cognitive battery, participants aged 23 to 35 improved overall speed and efficiency at both follow-ups; the 36 to 50 and 51 to 65 age groups showed few or no significant improvements.
  8. Hariharan R, Mousa A, Menon K, Feehan J, Ukropcová B, Ukropec J, Schön M, Majid A, Aldini G, de Courten M, Cameron J, Bell SM, de Courten B. Effects of Carnosine Supplementation on Cognitive Outcomes in Prediabetes and Well-Controlled Type 2 Diabetes: A Randomised Placebo-Controlled Clinical Trial. Pharmaceuticals (Basel). 2025;18(5):630. doi: 10.3390/ph18050630.PubMedUsed to support: Secondary analysis of a double-blind randomized trial in 49 adults with prediabetes or well-controlled type 2 diabetes. 2 g a day of carnosine for 14 weeks did not change any cognitive measure (Digit Symbol Substitution, Stroop, Trail Making A and B, CANTAB) versus placebo.
  9. Hsiao YF, Fan Z, Fan YY, Chung M. The Effects of Carnosine on Cognitive Function and Mental Health-A Systematic Review and Meta-Analysis. Nutrients. 2026;18(9):1385. doi: 10.3390/nu18091385.PubMedUsed to support: Systematic review of 13 studies (12 randomized trials). Five trials found no significant difference between L-carnosine and placebo on most cognitive measures. Pooled results from three trials by one research team found anserine plus carnosine improved delayed verbal recall but not immediate recall, and carnosine combined with anserine or antioxidants slightly improved MMSE scores. Strength of evidence was rated low; most mood and quality-of-life measures did not change.
  10. O'Toole TE, Wingard CJ, Bariess SK, Crandell CE, Amraotkar AR, Gao H, Bhatnagar A. Effects of carnosine supplementation on physical endurance: a placebo-controlled randomized clinical trial. J Int Soc Sports Nutr. 2026;23(1):2679716. doi: 10.1080/15502783.2026.2679716.PubMedUsed to support: Placebo-controlled randomized trial in 299 adults given 2 g a day of carnosine or placebo for about 12 weeks. Grip strength, gait speed and the other physical measures did not differ from placebo overall. Subgroup analyses found more calf raises in under-40s at 6 weeks and more steps on a 2-minute step test in men over 40 at 12 weeks.
  11. Harris RC, Tallon MJ, Dunnett M, Boobis L, Coakley J, Kim HJ, Fallowfield JL, Hill CA, Sale C, Wise JA. The absorption of orally supplied beta-alanine and its effect on muscle carnosine synthesis in human vastus lateralis. Amino Acids. 2006;30(3):279-89. doi: 10.1007/s00726-006-0299-9.PubMedUsed to support: Absorption and muscle-loading study. After histidine dipeptides given in chicken broth, carnosine was not detected in plasma while beta-alanine rose. Four weeks of L-carnosine in an amount isomolar to 6.4 g a day of beta-alanine raised muscle carnosine by about 66%, similar to the 64% seen with 6.4 g a day of beta-alanine.
  12. Everaert I, Taes Y, De Heer E, Baelde H, Zutinic A, Yard B, Sauerhöfer S, Vanhee L, Delanghe J, Aldini G, Derave W. Low plasma carnosinase activity promotes carnosinemia after carnosine ingestion in humans. Am J Physiol Renal Physiol. 2012;302(12):F1537-44. doi: 10.1152/ajprenal.00084.2012.PubMedUsed to support: In 25 healthy adults given a single 60 mg/kg dose of carnosine, only 8 showed a measurable rise in plasma carnosine (lasting up to 1 hour). Those with no rise had about twice the plasma carnosinase protein and about 1.5 times the enzyme activity, showing that this blood enzyme breaks down most ingested carnosine.
  13. Blancquaert L, Everaert I, Baguet A, Bex T, Barbaresi S, de Jager S, Lievens E, Stautemas J, De Smet S, Baron G, Gilardoni E, Regazzoni L, Aldini G, Derave W. Acute preexercise supplementation of combined carnosine and anserine enhances initial maximal power of Wingate tests in humans. J Appl Physiol (1985). 2021;130(6):1868-1878. doi: 10.1152/japplphysiol.00602.2020.PubMedUsed to support: Laboratory and small crossover studies. Carnosine is readily degraded by serum carnosinase-1; anserine is degraded more slowly, and adding carnosine slowed it further. Taking anserine plus carnosine (20 mg/kg each) before exercise raised power in the first 5 seconds of a Wingate sprint by about 6% in one study, and a second study reported about 3% higher peak power across three repeated Wingate tests.
  14. de Jager S, Blancquaert L, Van der Stede T, Lievens E, De Baere S, Croubels S, Gilardoni E, Regazzoni LG, Aldini G, Bourgois JG, Derave W. The ergogenic effect of acute carnosine and anserine supplementation: dosing, timing, and underlying mechanism. J Int Soc Sports Nutr. 2022;19(1):70-91. doi: 10.1080/15502783.2022.2053300.PubMedUsed to support: Three small studies in men. 30 mg/kg each of carnosine and anserine taken 60 minutes before exercise improved repeated-sprint peak power by 3% and peak torque by 4.5% in 11 men, but a second study of 15 men found no group-level improvement; people with lower carnosinase activity tended to benefit more.
  15. Ali AN, Su L, Newton J, Grayson AK, Taggart D, Bell SM, Baig S, Gardner I, de Courten B, Majid A. Dietary Carnosine Supplementation in Healthy Human Volunteers: A Safety, Tolerability, Plasma and Brain Concentration Study. Nutrients. 2025;17(13):2130. doi: 10.3390/nu17132130.PubMedUsed to support: Dose-escalation study in 16 healthy volunteers. Single oral doses up to 10 g were well tolerated; at 15 g, 77% had side effects, most often headache, nausea and tingling. Plasma carnosine peaked within the first hour and little remained after 4 hours; brain carnosine (5 people, MR spectroscopy) rose at 1 hour and returned to baseline by 5 hours. 5 g twice daily for 4 weeks (4 people) caused no adverse events. Funded by Hestia Investments.
  16. Baba SP, Amraotkar AR, Hoetker D, Gao H, Gomes D, Zhao J, Wempe MF, Rice PJ, DeFilippis AP, Rai SN, Pope CA 3rd, Bhatnagar A, O'Toole TE. Evaluation of supplementary carnosine accumulation and distribution: an initial analysis of participants in the Nucleophilic Defense Against PM Toxicity (NEAT) clinical trial. Amino Acids. 2024;56(1):55. doi: 10.1007/s00726-024-03414-5.PubMedUsed to support: Randomized placebo-controlled trial of 2 g a day of carnosine for 12 weeks. Red blood cell carnosine roughly doubled and urinary carnosine rose nearly sevenfold, and a urinary conjugate of carnosine with propanal, a lipid-oxidation product, nearly doubled. No adverse reactions were reported, and kidney, liver and heart function and blood electrolytes did not change.