Amino Acid
L-Histidine
Also known as: Histidine, His, L-Histidine HCl, L-Histidine Hydrochloride
L-Histidine is an essential amino acid precursor to histamine and carnosine, involved in immune function, wound healing, and neurotransmission. Evidence for isolated supplementation in healthy adults is limited, though histidine is necessary for normal physiological function.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Primary uses
- Histamine precursor
- Carnosine synthesis
- Immune support
- Antioxidant (via carnosine)
- Amino acid supplementation
- Histamine production
- Protein synthesis
- Immune function support
How it works
- Decarboxylated to histamine
- Combines with beta-alanine to form carnosine
- Metal ion chelation
- Important for hemoglobin structure
Dosage
- Typical range
- 500-2000 mg daily
- Timing
- With meals
- With food
- With or without
- Duration
- Safe long-term
- Special populations
- Those with histamine issues use caution
Forms
- Capsule
- Powder
- Hydrochloride salt (HCl)· 70/100
Safety
Common side effects
- Well tolerated
Contraindications
- Severe histamine intolerance
Products containing L-Histidine
Top-scoring supplements in our catalog that list L-Histidine on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
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Evidence notes
Established physiological roles in multiple systems
Grade B: Some human trials support key claims; further confirmation needed.
Related in Amino Acid
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.