L-Histidine
L-Histidine
An essential amino acid that serves as a precursor to histamine and carnosine, supporting immune function, digestion, and antioxidant defense.
L-Histidine is an essential amino acid particularly important during growth periods. It's the precursor to histamine (involved in immune response, stomach acid, and neurotransmission) and combines with beta-alanine to form carnosine (an intracellular antioxidant). It plays roles in immune function, wound healing, tissue repair, and is a component of hemoglobin. Low histidine has been linked to rheumatoid arthritis and anemia.
Mechanisms of Action
Histamine Precursor
Converted to histamine
Carnosine Synthesis
Combines with beta-alanine to form carnosine
Hemoglobin Component
Important for oxygen transport
Recommended Dose
1-4g daily
Loading: Not required
Optimal Timing
- Between meals for better absorption
- Can divide into 2-3 doses
Can be taken without food
Best Form
L-Histidine powder or capsules
Pure L-histidine is standard. Often included in EAA blends.
Duration
Minimum: 4 weeks
Optimal: 12 weeks
Cycling: Not required
Note: Best absorbed on empty stomach. Those with histamine intolerance should be cautious.
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Immune Function
Supported immune response
Antioxidant Support
Enhanced carnosine levels
Tissue Repair
Support for wound healing
Some studies show low histidine levels; supplementation may help
Who Should NOT Take This
- Histamine intolerance (may worsen symptoms)
- Mast cell disorders
Drug Interactions
Histidine converts to histamine; may reduce antihistamine effectiveness
Folic acid deficiency can cause FIGLU buildup with histidine use
Possible Side Effects
Tip: Start low; avoid if histamine intolerant
Warnings
- May not be suitable for those with histamine intolerance
- High doses can increase histamine levels
Top studies from 39+ peer-reviewed papers
Maugeri S et al. • Cells (2023)
“Despite this evidence, more preclinical and clinical studies are needed to better understand carnosine's anti-tumoral activity, especially in the context of breast cancer.”
Key Findings:
- Among the different types of cancer, breast cancer represents the most common non-skin cancer among women, accounting for an estimated 15% of all cancer-related deaths in women.
- When tested in mice with induced breast cancer, carnosine proved to be non-toxic to healthy cells and exhibited chemopreventive activity by reducing tumor growth.
- Some evidence has also been reported at the clinical level.
- A randomized phase III prospective placebo-controlled trial showed the ability of Zn-carnosine to prevent dysphagia in breast cancer patients undergoing adjuvant radiotherapy.
Gong J et al. • Nutrients (2022)
“This study identified obesity microbial biomarkers, providing fertile targets for the management of obesity.”
Key Findings:
- The relative abundance of Lachnoclostridium and Faecalitalea were higher in people with simple obesity, while 23 genera, including Christensenellaceae_R-7_group, Akkermansia, Alistipes, and Butyricimonas, etc., were significantly lower.
- The random forest model achieved a high accuracy (AUC = 0.83).
- The adenine and adenosine salvage pathway (PWY-6609) and the L-histidine degradation I pathway (HISDEG-PWY) were clustered in obese patients, while amino acid biosynthesis and degradation pathways (HISDEG-PWY, DAPLYSINESYN-PWY) were decreased.
- This study identified obesity microbial biomarkers, providing fertile targets for the management of obesity.
Shulpekova YO et al. • Nutrients (2021)
“The purpose of this review is to build an extraordinarily specific method of histamine cycle assessment in regard to non-allergic intolerance and its possible dire consequences that can be suffered.”
Key Findings:
- Most cases of clinical manifestations of histamine intolerance are non-specific due to tissue-specific distribution of different histamine receptors and the lack of reproducible and reliable diagnostic markers.
- The diagnosis of histamine intolerance is fraught with difficulties, in addition to challenges related to the selection of a proper treatment strategy, the regular course of recovery, and reduced amelioration of chronic symptoms due to inappropriate treatment prescription.
- The purpose of this review is to build an extraordinarily specific method of histamine cycle assessment in regard to non-allergic intolerance and its possible dire consequences that can be suffered.
Holeček M • Nutrients (2020)
“Of concern should be findings of hepatic enlargement and increases in ammonia and glutamine and of decrease in branched-chain amino acids (valine, leucine, and isoleucine) in blood plasma indicating that HIS supplementation is inappropriate in patients with liver disease.”
Key Findings:
- Several decades of experience have confirmed the effectiveness of HIS as a component of solutions used for organ preservation and myocardial protection in cardiac surgery.
- Further studies are needed to elucidate the effects of HIS supplementation on neurological disorders, atopic dermatitis, metabolic syndrome, diabetes, uraemic anaemia, ulcers, inflammatory bowel diseases, malignancies, and muscle performance during strenuous exercise.
- Signs of toxicity, mutagenic activity, and allergic reactions or peptic ulcers have not been reported, although HIS is a histamine precursor.
- Of concern should be findings of hepatic enlargement and increases in ammonia and glutamine and of decrease in branched-chain amino acids (valine, leucine, and isoleucine) in blood plasma indicating that HIS supplementation is inappropriate in patients with liver disease.
Schön M et al. • Nutrients (2019)
“In this review, we aim to provide a comprehensive overview of the role of carnosine in neurological, neurodevelopmental, neurodegenerative, and psychiatric disorders, summarizing current evidence from cell, animal, and human cross-sectional, longitudinal studies, and randomized controlled trials.”
Key Findings:
- Neurological, neurodegenerative, and psychiatric disorders represent a serious burden because of their increasing prevalence, risk of disability, and the lack of effective causal/disease-modifying treatments.
- There is a growing body of evidence indicating potentially favourable effects of carnosine, which is an over-the-counter food supplement, in peripheral tissues.
- In this review, we aim to provide a comprehensive overview of the role of carnosine in neurological, neurodevelopmental, neurodegenerative, and psychiatric disorders, summarizing current evidence from cell, animal, and human cross-sectional, longitudinal studies, and randomized controlled trials.
Study Type Distribution
Goals This Supplement Supports
This information is for educational purposes only and is not intended as medical advice. Always consult a qualified healthcare provider before starting any supplement.