Anserine

Other Names

(2S)-2-(3-aminopropanamido)-3-(1-methyl-1H-imidazol-5-yl)propanoic acid(2S)-2-(3-aminopropanoylamino)-3-(3-methylimidazol-4-yl)propanoic acid2-(3-aminopropanoylamino)-3-(3-methylimidazol-4-yl)propanoic acid3-Methyl-N,alpha-(beta-alanyl)-L-histidineAnserinbeta-Ala-3-methyl-Hisbeta-alanyl-1-methylhistidinebeta-Alanyl-3-methyl-L-histidinebeta-alanyl-3-methylhistidinebeta-Alanyl-N(pi)-methyl-L-histidinebeta-alanyl-N1-methylhistidinebeta-alanyl-Npi-methyl-L-histidineH-Beta-Ala-His(3-Me)-OHH-β-Ala-1-Methyl-L-HisH-β-Ala-His(3-Me)-OHL-AnserineL-Histidine, beta-alanyl-3-methyl-L-Histidine, N-(3-amino-1-hydroxypropylidene)-3-methyl-, (E)-L-Histidine, N-β-alanyl-3-methyl-L-N-b-alanyl-3-methyl-HistidineL-N-β-alanyl-3-methyl-HistidineN-beta-Alanyl-3-methyl-L-histidineN-β-alanyl-1-methyl-L-histidineN-β-Alanyl-3-methyl-L-histidineβ-Ala-3-methyl-Hisβ-Alanyl-3-methyl-L-histidineβ-alanyl-3-methylhistidineβ-Alanyl-N(Pi)-methyl-L-histidineβ-Alanyl-N-π-methyl-L-histidine

Synopsis

Anserine: A Comprehensive Encyclopedic Reference

1. Identity, Chemical Nature, and Physical Properties

Anserine is a naturally occurring dipeptide belonging to the family of histidine-containing dipeptides (HCDs), also referred to as imidazole dipeptides. Anserine (β-alanyl-N-π-methyl-L-histidine) is the main histidine dipeptide found in the skeletal muscle tissue of various animals. It is a dipeptide containing β-alanine and 3-methylhistidine, and is a derivative of carnosine, which has been methylated.

Nomenclature note: There is considerable confusion with regard to the nomenclature of the methylated nitrogen atoms, with older literature designating anserine (N^π-methylated) as β-alanyl-N1-methyl-histidine, whereas according to IUPAC this is β-alanyl-N3-methyl-histidine. The compound is registered under CAS number 584-85-0 and has a molecular weight of 240.26 g/mol. The pKa of the imidazole ring of histidine, when contained in anserine, is 7.04, making it an effective buffer at physiologic pH.

Anserine is structurally related to carnosine (β-alanyl-L-histidine) but differs by a single methyl group on the π-nitrogen of the histidine imidazole ring. The first enzymatic pathway of anserine synthesis is through carnosine N-methyltransferase (CMT), which catalyzes the transfer of a methyl group of S-adenosylmethionine (SAM) on carnosine to form anserine. Anserine can be synthesized either from carnosine via carnosine N-methyltransferase or from 1-methylhistidine via carnosine synthase.

Anserine has biological activities similar to those of carnosine, including buffering activity, antioxidant properties, metal ion chelation, and anti-aggregation effects. Because of its methylation, anserine is more stable in serum and resistant to degradation than carnosine, and compared with carnosine, anserine has a higher antioxidant capacity.

2. Natural Sources and Distribution

Anserine (beta-alanyl-N(Pi)-methyl-L-histidine) is an abundant constituent of skeletal muscles and brain of many vertebrates. Anserine was reported to be a major L-histidine-containing dipeptide in avian tissues, reaching up to 43 mM in chicken pectoral muscle. It has also been detected in muscle of fish (2.5 up to 41 mM), cats (8 mM), and rabbits (17 mM), but not in frogs and humans.

Anserine is the main histidine dipeptide found in the skeletal muscle tissue of various animals, including salmon, lions, kangaroos, tuna, and trout. In the daily diet, anserine is found in fish, beef, and chicken. The skipjack tuna, commonly known as bonito fish, is one of the main sources of anserine; bonito muscles serve as the raw material for producing fish extracts rich in anserine (referred to as SEAns).

Most animals, except humans, also possess a methylated variant of carnosine, either anserine or ophidine/balenine, collectively called the histidine-containing dipeptides. Anserine does not occur in human organs, but dietary uptake is common for non-vegetarians. Anserine is also found in human kidney, where it is thought to arrive through dietary intake and renal handling.

3. Commercial Forms and Preparations

Anserine is available in several distinct product forms:

Purified fish muscle extracts (SEAns): The membrane separation process applied to bonito meat increases the concentration of anserine from 1.38% to 10.6%; further purification processes can achieve anserine hydrochloride with a purity of 98%.
Chicken breast extract (CBEX): Chicken meat extracts contain high concentrations of carnosine (β-alanyl-L-histidine) and anserine (β-alanyl-π-methyl-histidine) in a 1:2 to 1:3 ratio.
Chicken essence (CE): Chicken essence (CE) is the cooked, concentrated, liquid extract from chicken, which is a popular traditional remedy amongst Asians. CE consists of major components of dipeptides and free amino acids, where carnosine and anserine are the most concentrated active ingredients.
Synthetic anserine: Chemically synthesized L-anserine has been used in human research, and it has been confirmed that nutritionally relevant doses are well absorbed and that its degradation by human serum carnosinase is less pronounced compared with carnosine.
Combined anserine/carnosine formulas: Several clinical trials have used standardized preparations combining anserine and carnosine, typically in a 3:1 ratio, as capsules or tablets.

4. Traditional and Historical Use

Chicken essence is a popular traditional remedy in Asia, which is believed to improve cognitive functions. In traditional South-Asian medicine, chicken extracts are used to alleviate stress or mild disease symptoms. Today, multiple brands produce chicken essence across Taiwan, Singapore, Malaysia, and other Asian markets, and it remains a common gift for new mothers, elderly relatives, students, and anyone recovering from surgery or illness.

The compound anserine itself was isolated and chemically characterized during the early twentieth century. Carnosine and its structural and functional relative, anserine, were found in skeletal muscles at the beginning of the century. Before its chemical identification, the health effects attributed to chicken and fish broths in various traditional systems were not understood at a molecular level. The key nutritional components of chicken essence are bioactive peptides and amino acids, particularly two compounds called carnosine and anserine that are naturally abundant in chicken meat; these small peptides are what set chicken essence apart from simply drinking protein powder mixed in water.

The dipeptide is contained abundantly in breast meat of birds flying long distances or in muscle of marine life making excursions of long distances, such as tuna, bonito, or whale. This observation aligns with traditional fishing communities in East and Southeast Asia, Japan, and coastal China who prepared concentrated fish broth and bird-meat tonics for endurance and recovery. Essence of chicken is a popular Asian nutritional supplement that is often taken to improve metabolism and general health.

5. Key Constituents, Biochemistry, and Mechanisms of Action

5.1 Molecular Structure and Biosynthesis

Anserine (β-alanyl-N-π-methyl-L-histidine) and balenine (β-alanyl-N-τ-methyl-L-histidine) are naturally occurring derivatives of carnosine (β-alanyl-L-histidine) that have been reported to be present in skeletal muscle and the central nervous system of vertebrates. The single methyl group differentiating anserine from carnosine is added by the enzyme carnosine N-methyltransferase, specifically by carnosine N-methyltransferase (CARNMT1).

The true carnosinase (CN1, EC 3.4.13.20) catalyzes hydrolysis of carnosine and anserine and is found in serum and brain. Interestingly, these two forms of carnosinases are characterized by a much higher activity toward carnosine compared with anserine, suggesting that anserine is a more metabolically stable derivative of carnosine.

5.2 Intracellular pH Buffering

One of the most studied properties of anserine and the related dipeptides is their ability to buffer intracellular pH in rapidly contracting muscle. Originally, these dipeptides have been postulated to serve as buffers neutralizing lactic acid produced in working muscle due to their abundance and pKa which is close to physiological pH. Carnosine, as well as other beta-alanine-derived dipeptides including anserine, act as antioxidant buffers in muscle tissue, constituting up to 20% of the buffer capacity in type I and II muscle fibres; this buffering is important for maintaining tissue pH in muscle during the breakdown of glycogen to lactic acid. Anserine's buffering activity is superior to that of carnosine at neutral pH.

5.3 Antioxidant Activity

Anserine has a higher antioxidant capacity compared to carnosine. Roles of these histidine-related compounds include chelation of metal ions, quenching of singlet oxygen, and binding of hydroperoxides; the data suggest a role for these histidine-related compounds as endogenous antioxidants in brain and muscle. Both anserine and carnosine bind copper and other transition metals, and chelation of transition metals is one mechanism for their antioxidant activity.

A study of protective actions in diabetic conditions found that in tubular cells stressed with 25 mM glucose or 20–100 µM hydrogen peroxide, anserine but not carnosine, increased intracellular heat shock protein (Hsp70) mRNA and protein levels. In HK-2 cells stressed with glucose, co-incubation with anserine also increased hemeoxygenase (HO-1) protein and reduced total protein carbonylation.

5.4 Anti-Glycation Activity

Although it has long been proposed to serve as a proton buffer, radical scavenger, and transglycating agent, its physiological function remains not entirely explained. The anti-glycation property — the capacity to prevent the formation of advanced glycation end-products (AGEs) — is considered one of the most clinically relevant mechanisms of this dipeptide. According to numerous studies in rodents, supplementation of the histidine-containing dipeptides carnosine and anserine mitigates diabetic nephropathy, based on a broad range of protective actions, including anti-oxidative effects, 4-hydroxynonenal (4-HNE) quenching, methylglyoxal (MG) polymerization, and hydrogen sulfide formation.

5.5 Hypochlorous Acid (HClO) Scavenging

Neuroinflammation has been recognized as a promising target for strategies treating Alzheimer's disease. In particular, it has been shown that neutrophils and MPO-mediated neuroinflammatory responses with the production of HClO (hypochlorous acid) play a role in the progression of AD. Anserine has been studied as an efficient scavenger of HClO, which is a reactive oxygen species produced by activated neutrophils and associated with tissue damage in neurodegenerative disease.

5.6 Absorption, Transport, and Metabolism

The bioactive dipeptide derivative anserine (beta-alanyl-1-N-methyl-L-histidine) is absorbed from the human diet in intact form at the intestinal epithelium. Anserine and carnosine interact with the human intestinal peptide transporter and are transported by hPEPT1 in an active, electrogenic H+ symport. As PEPT1 is the predominant transport system for di- and tripeptides at the intestinal epithelium, this transporter is most probably responsible for the intestinal absorption of anserine after food intake.

Once absorbed, anserine undergoes partial hydrolysis by serum carnosinase (CN1). Anserine is a substrate of carnosinase, and 85–90% of dietary intakes in humans are degraded and excreted as 1-methyl-histidine. The elimination half-life of 1-methylhistidine is on the order of 17 hours whereas the elimination half-life of anserine is on the order of 4 hours. Critically, in several in vitro experiments, the hydrolysis rate of anserine is 30–50% of carnosine's, meaning that carnosine, anserine, and balenine are respectively good, intermediate, and poor substrates for the CN1 enzyme.

In human sera, carnosine but not anserine is rapidly cleaved by carnosinase, limiting its effectiveness. This differential resistance to degradation is a key pharmacological advantage of anserine over carnosine for supplementation purposes. Ingesting anserine elicited dose-dependent peak concentrations of 0.5–3.1 µM. Increasing plasma anserine appeared to pose less of a challenge compared to carnosine; nevertheless, up to a dose of 10 mg/kg, measurable plasma anserine was mainly observed in people with low CN1 enzyme activity.

6. Scientific Evidence by Area of Use

6.1 Cognitive Function and Neuroprotection

Overview: The most robustly studied clinical application of anserine (typically as an anserine/carnosine combination) is the preservation of cognitive function in elderly individuals and those with mild cognitive impairment (MCI).

Verbal Memory in Healthy Elderly (RCT, 2016): The goal of the study was to determine whether anserine/carnosine supplementation (ACS) is capable of preserving cognitive function of elderly people. In a double-blind randomized controlled trial, volunteers were randomly assigned to an ACS or placebo group at a 1:1 ratio; the ACS group took 1.0 g of an anserine/carnosine (3:1) formula daily for 3 months. Thirty-nine healthy elderly volunteers (60–78 years old) completed the follow-up tests. Among the tests, delayed recall verbal memory assessed by the Wechsler Memory Scale-Logical Memory showed significant preservation in the ACS group compared to the placebo group (p = 0.0128). Blood analysis revealed a decreased secretion of inflammatory cytokines, including CCL-2 and IL-8, in the ACS group.

Cognitive Function and Physical Capacity in Elderly (RCT, 2014): The aim of this study was to investigate the potential beneficial effects of dietary anserine and carnosine (CRC) supplementation on cognitive functioning and physical activity of the elderly. Fifty-six subjects (65+) were allocated to the CRC group or placebo group at a 1:1 ratio, using a double-blind procedure; data were collected at the baseline and after 13-weeks of supplementation. Chicken meat extract (CME) containing 40% of CRC components (2:1 ratio of anserine to carnosine) was administered 2.5 g per day, which allowed reaching the level of 1 g CRC in dipeptide supplement. The mean values of the Short Test of Mental Status (STMS) scores showed a significant (p < 0.04) increase only in the CRC group, in the subscores of construction/copying, abstraction, and recall.

MCI with APOE4 Subanalysis (RCT, 2019): A randomized, double-blind, placebo-controlled 12-week trial was performed; 54 subjects with MCI were randomized to an active group ingesting 750 mg of anserine and 250 mg of carnosine per day or a placebo (1:1). The score improvement in the global Clinical Dementia Rating (gloCDR) was superior in the active group than placebo (p = 0.023). No beneficial effect in the active group was detected in the other psychometric tests including the MMSE, the Wechsler Memory Scale, and the ADAS. When APOE4 positive subjects were separately analyzed, beneficial change was observed in MMSE (p = 0.025) as well as in gloCDR (p = 0.026).

Anserine Alone in MCI (RCT, 2021): In a study evaluating the effects of anserine as a scavenger of HClO on the protection of cognitive declines in persons with MCI, 36 MCI individuals were assigned either to an active arm, who received 500 mg anserine per day, or a placebo arm, for 12 weeks. To assess cognitive function, MMSE was performed at baseline and after ingestion. The data for 30 subjects who completed the follow-up tests were analyzed. A significant difference was detected in the change score of MMSE between the active arm (1.9 ± 2.0; n = 15) and the placebo arm (0 ± 2.8; n = 15) (p = 0.036).

Systematic Review and Meta-Analysis (2021): A systematic review and meta-analysis found five studies matching selection criteria; carnosine/anserine was administered for 12 weeks at a dose of 1 g/day and improved global cognitive function, whereas no effects were detected on depressive symptoms.

Evidence strength: The evidence for cognitive benefits from anserine-containing supplements in elderly/MCI populations is promising, being derived from multiple small randomized, double-blind, placebo-controlled trials. However, most trials are of short duration (12–13 weeks), involve small sample sizes, and use combination formulas (anserine + carnosine), making it difficult to isolate the contribution of anserine alone. The systematic review was limited to five qualifying trials. This area warrants larger and longer confirmatory trials.

6.2 Animal/Preclinical Evidence for Neurovascular Protection in Alzheimer's Disease

One study examined the effects of anserine on AβPPswe/PSEN1dE9 Alzheimer's disease model mice over 18 months old, at which these mice exhibit detectable memory deficits. It was speculated that anserine might reverse the AD-related degeneration of brain pericytes through a mechanism similar to the compensation of skeletal-muscle tissue, via its strong buffering activity. Anserine might protect neurovascular-unit function by improving pericyte function, thereby suppressing neuroinflammation and restoring cognitive function in AD-model mice. Anserine treatment ameliorated pericyte degeneration and glial neuroinflammation in the AD mouse brain; anserine treatment increased the rate of pericyte coverage by reversing the pericyte shrinkage observed in aged AD-model mice.

Evidence strength: This evidence is preclinical (animal model only) and cannot be directly applied to human clinical outcomes. It provides a mechanistic rationale for cognitive benefit observed in human trials.

6.3 Exercise Performance and Anti-Fatigue

Overview: Anserine has been examined both as part of food extracts (chicken broth, bonito extract) and as a purified supplement for its potential to improve exercise performance and reduce fatigue.

Wingate Sprint Performance (Human Crossover RCTs, 2022): Studies reveal that acute ingestion of 30 mg/kg⁻¹ of both carnosine and anserine, 60 minutes before high-intensity exercise, can potentially improve performance, such as short cycling sprints or maximal muscle contractions. Subjects with lower carnosinase activity, and thus a slower breakdown of circulating dipeptides, appear to benefit more from this ergogenic effect. Neither the involvement of a direct effect on neuromuscular function, nor an indirect effect on recovery through increased muscle perfusion could be confirmed as potential mechanism of action; the ergogenic mechanism therefore remains elusive.

30-Day Supplementation Protocol: A 30-day supplementation protocol with a dose of 4 g of anserine and carnosine per day reduces blood lactate concentrations and the level of fatigue perceived after performing high-intensity endurance exercise.

Salmon Muscle Extract (SEAns) in Physically Normal Men: Exercise tolerance testing on physically normal men was conducted to evaluate the anti-fatigue effect of salmon muscle extract containing anserine (SEAns) in a clinical test. SEAns inhibited creatine phosphokinase activity, suppressed elevation of the cortisol level in blood, and improved exercise endurance. The conclusion was that SEAns reduces physical fatigue and mental stress.

Narrative Review Summary: The findings of the broader literature indicate that anserine may improve physical performance and reduce fatigue, particularly in quick, repetitive activities. Several studies support the benefits of combining anserine with carnosine in humans, with some papers indicating that acute supplementation with a dosage of 25–30 mg/kg body weight of anserine and carnosine has beneficial effects on power increases, maximal muscle contractions, ergogenic potential, and performance during short cycling sprints.

Evidence strength: The evidence for exercise performance benefit is preliminary to moderate. Most human studies are of short duration or use combination products containing both anserine and carnosine, making attribution to anserine alone difficult. Individual variability in serum carnosinase (CN1) activity significantly influences outcomes. The diversity of the presented studies and their limitations do not provide an opportunity to confirm the ergogenic properties of the histidine-containing compounds studied definitively.

6.4 Kidney (Renal) Protection and Diabetic Nephropathy

Overview: Anserine has been investigated for its potential to protect the kidney under conditions of hyperglycemia and oxidative stress, primarily in preclinical models with some mechanistic human cell data.

In vitro and Animal Data: Anserine has a higher antioxidant capacity compared to carnosine (p < 0.001). In tubular cells stressed with 25 mM glucose or 20–100 µM hydrogen peroxide, anserine but not carnosine, increased intracellular heat shock protein (Hsp70) mRNA and protein levels. Three intravenous anserine injections every 48 h in 12-week-old db/db diabetic mice improved blood glucose by one fifth, vascular permeability by one third, and halved proteinuria (all p < 0.05). Anserine is a potent antioxidant and activates the intracellular Hsp70/HO-1 defense system under oxidative and glycative stress; short-term anserine treatment in diabetic mice improves glucose homeostasis and nephropathy.

Anserine exerts higher antioxidative action than carnosine and activates the intracellular Hsp70/HO-1 defense system under oxidative and glycative stress. It is unclear how far the nephroprotective actions of carnosine and anserine are exerted via direct protective effects or indirectly via improving glucose homeostasis. The promising experimental studies in rodents have stimulated first clinical trials, which suggest a significant protective potential of carnosine in humans, even though carnosine and anserine are both rapidly metabolized by human serum carnosinase 1 (CN1).

Histidine-containing dipeptides like carnosine and anserine have protective functions in both health and disease; animal studies suggest that carnosine can be metabolized within the kidney. CNDP1 expression was correlated with the degradation of carnosine and anserine (r = 0.88 and 0.81, respectively).

Evidence strength: Renal protection data are predominantly from animal models (rodents) and in vitro human cell lines (HK-2 cells). No large randomized human clinical trials of anserine for kidney disease have been identified. Evidence is considered preliminary and mechanistic.

6.5 Anti-Glycation and Metabolic Health

Optimization of carnosine and anserine extraction from chicken breast was performed to obtain maximized physiological activities for anti-glycation and anti-oxidation. Extracts prepared from laying hens under optimum conditions showed 57% inhibition of advanced glycated end-product formation, 64% inhibition of lipid peroxidation, and 61% DPPH radical scavenging effects.

High concentrations of anserine reduced interstitial inflammation and alleviated kidney fibrosis in type-1 diabetic mice with carnosinase-1 knock-out on high-fat diet. In another high-fat diet model, anserine treatment exhibited hypolipidemic and anti-obesity effects by inhibiting p-NF-κB p65 expression.

Evidence strength: These findings are derived primarily from animal models and in vitro assays. Human evidence in this specific domain is currently absent.

6.6 Hyperuricemia and Uric Acid Metabolism

The therapeutic ability of anserine as a bioactive peptide was validated through a comprehensive multiomics analysis of a rat model of hyperuricemia. Anserine was observed to improve liver and kidney function and modulate urate-related transporter expressions in the kidneys. Additionally, anserine regularly changed the gut microbiota, thereby ameliorating purine metabolism abnormalities and alleviating inflammatory responses.

Evidence strength: This evidence is restricted to a rat model; no human clinical trials on anserine for hyperuricemia have been identified in the reviewed literature.

6.7 Chicken Essence for Cognitive Enhancement: Asian Traditional Preparation Evidence

A systematic review was conducted to determine the cognitive-enhancing effects of chicken essence. Databases were systematically searched for randomized controlled trials with human subjects consuming chicken essence with cognitive test outcomes. An animal study found that oral administration of chicken essence to rats increased the concentration of carnosine and anserine in the brain; however, there was no clear indication of how this affects cognitive functions in human beings.

7. Body Systems and Health Areas Associated with Anserine

Nervous system / Brain: Cognitive function preservation, neuroprotection via HClO scavenging, pericyte function support, anti-neuroinflammatory effects. Explored in the context of MCI and Alzheimer's disease.
Skeletal muscle: Intramuscular pH buffering during high-intensity exercise, anti-fatigue, ergogenic potential, antioxidant protection from exercise-induced damage.
Kidney: Antioxidant and anti-glycation protection of tubular cells, potential amelioration of diabetic nephropathy, modulation of urate transport.
Metabolic system: Evidence suggests the potential therapeutic role that carnosine and related dipeptides could exert against type 2 diabetes, being antioxidant, anti-glycation, and anti-nitrating compounds, also able to affect glycemic control and prevent diabetic complications.
Immune system: Effects on muscle working capacity, the stability of membrane-bound enzymes, as well as immunomodulating properties, could not be explained by pH-buffering capacity or the formation of secondary metabolites histidine and beta-alanine alone.

8. Dosages Reported in Human Studies

The following dosages are reported directly from published human clinical studies and should not be interpreted as recommended doses:

1.0 g/day of an anserine/carnosine (3:1) formula (equivalent to approximately 750 mg anserine) taken daily for 3 months in healthy elderly volunteers.
750 mg anserine and 250 mg carnosine per day in a 12-week randomized double-blind trial in subjects with MCI.
500 mg anserine per day in a 12-week randomized study in persons with MCI.
2.5 g/day of chicken meat extract containing 40% CRC components (2:1 ratio anserine to carnosine), yielding 1 g of combined dipeptides, over 13 weeks in elderly subjects.
30 mg/kg body weight of both carnosine and anserine taken acutely 60 minutes before high-intensity exercise in performance studies.
4 g/day of anserine and carnosine over a 30-day supplementation protocol in exercise studies assessing blood lactate and perceived fatigue.
In the systematic review meta-analysis of five studies, administration was generally 1 g/day for 12 weeks for cognitive function outcomes.

9. Safety Considerations and Pharmacological Interactions

9.1 Reported Safety in Clinical Trials

There were no reported or observed adverse events, severe or otherwise, during a randomized double-blind 12-week anserine/carnosine supplementation trial in MCI subjects. Data abnormalities that were thought to be associated with the test supplement administration were not found in the blood analysis at follow-up.

Essence of chicken, rich in anserine and carnosine, has been sold commercially for over 40 years with no detrimental side effects.

9.2 Degradation to 1-Methylhistidine

Anserine is a substrate of carnosinase, and 85–90% of dietary intakes in humans are degraded and excreted as 1-methyl-histidine. This metabolite, 1-methylhistidine, is considered a biomarker of dietary meat intake and has not been associated with clinically significant adverse effects at levels arising from dietary or supplemental anserine intake.

9.3 Carnosinase Activity and Inter-Individual Variability

A notable pharmacological interaction involves individual variation in serum carnosinase (CN1) activity. Subjects with lower carnosinase activity, and thus a slower breakdown of circulating dipeptides, appear to benefit more from ergogenic effects of anserine supplementation. An association between the CNDP1 Mannheim allele and reduced serum CN1 activity exists for all three dipeptides, but there is no simple correlation to serum dipeptide concentrations, though anserine and homocarnosine inhibit carnosinase activity.

9.4 Liver Disease and Altered CN1 Levels

Patients with liver cirrhosis have low CN1 activity and low CN1 concentrations compared to the normal range, suggesting that pharmacokinetics of anserine may be substantially altered in individuals with liver disease, as reduced carnosinase activity would result in reduced degradation and potentially higher circulating anserine levels after supplementation.

9.5 Anserinuria and Underlying Metabolic Conditions

Elevated anserine may result from dietary overload of protein and may be temporary or episodic with no clinical consequence. However, zinc deficiency can be a cause of peptidase weakness; also, pancreatic dysfunction or digestive disorder can result in increased uptake and excretion of anserine. Elevated anserine together with subnormal levels of essential or semi-essential amino acids is consistent with incomplete digestive proteolysis and malabsorption.

9.6 Note on Carnosine Safety as a Comparator

Specific safety data for high-dose purified anserine supplementation in humans is limited. For comparison, formal dose-escalation data exist for carnosine, to which anserine is structurally related: carnosine at an oral dose of up to 10 g is safe and well tolerated, in a single dose and in divided doses as a long-term dosing strategy, in the majority of individuals. No equivalent formal toxicology dose-escalation study was identified for purified anserine.

10. Evidence Summary and Research Gaps

The current body of evidence suggests that anserine, as a naturally occurring imidazole dipeptide from fish and poultry, is a bioactive compound with mechanistically plausible and clinically relevant properties. Human clinical trial evidence is strongest — though still preliminary — for cognitive function preservation in elderly individuals and those with MCI, where multiple small RCTs have been conducted. Evidence for exercise ergogenicity is supported by a rationale grounded in intramuscular pH buffering and carnosinase-resistance pharmacokinetics, with mixed results in human performance studies. Evidence for renal protection and metabolic benefits is currently preclinical.

Significant research gaps include: the absence of large-scale, long-term RCTs for any indication; the need to isolate the effects of anserine from carnosine in combination trials; the need for formal pharmacokinetic and safety profiling of purified anserine at supplemental doses; and the need to assess how CN1 genotype or activity influences clinical outcomes across different populations.

References

Health Conditions

Health conditions that Anserine may help support.

No conditions available.

Body Systems

Body systems that Anserine may help support.

No body systems available.