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.
Every L-Histidine product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | BulkSupplements L-Histidine HCl Powder | 88 A | $0.05 |
| 2 | Thorne Amino Complex - Travel Packs - Berry | 85 A- | $1.20 |
| 3 | Thorne Amino Complex - Travel Packs - Lemon | 85 A- | $1.20 |
| 4 | Thorne Amino Complex - Berry | 84 A- | $1.47 |
| 5 | Thorne Amino Complex - Lemon | 84 A- | $1.47 |
| 6 | Pure Encapsulations Essential Aminos | 81 A- | $0.31 |
| 7 | Thorne Amino Complex | 80 A- | $1.20 |
| 8 | Pure Encapsulations Amino-NR | 79 B+ | $0.78 |
| 9 | Double Wood Essential Amino Acid Supplement | 77 B+ | $0.27 |
| 10 | Country Life Aller-Max | 74 B+ | $0.69 |
| 11 | Pure Encapsulations Amino Replete | 73 B+ | $0.88 |
| 12 | Integrative Therapeutics Detoxication Factors | 64 B- | $1.17 |
Scored on dose accuracy, form, label transparency and third-party testing. Per-serving cost is list price divided by servings per container. No brand pays to be listed or ranked.
Common questions
How much L-Histidine should I take?
The typical range is 500-2000 mg daily. Safe long-term
When should I take L-Histidine?
With meals. With or without.
Which form of L-Histidine is best?
Capsule — Common form. Other forms in the catalog: Powder, Hydrochloride salt (HCl).
Is L-Histidine safe?
Commonly reported: Well tolerated. Serious warnings: May increase histamine in sensitive individuals. Caution in kidney disease
Which L-Histidine supplement scores highest?
BulkSupplements L-Histidine HCl Powder, at 88/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Primary uses
- Histamine precursor
- Carnosine synthesis
- Immune support
- Antioxidant (via carnosine)
- Amino acid supplementation
- Histamine production
- Protein synthesis
- Immune function support
What systematic reviews concluded
Outcomes that systematic reviews of L-Histidine reached a verdict on: 1 with a benefit, 1 with no effect. Each is quoted from a review and linked to it on PubMed. How these were read.
Reviews found a benefit (1)
“This meta-analysis found that beta-alanine is ergogenic for Yo-Yo test performance in athletes when the supplementation protocol lasts between 6 and 12 weeks and when using the level 2 variants of the Yo-Yo test.” PMID 34024507
Reviews found no effect (1)
“Most of the studies did not show significant effects in a wide range of mood and depression outcome measures or health-related QOL (data cannot be meta-analyzed).” PMID 42123986
2 findings from reviews in specific patient groups (such as cancer, pregnancy or surgery) are not shown here.
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.
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.