Amino Acid
L-Threonine
Also known as: Threonine, Thr
Essential amino acid important for protein synthesis, immune function, and gut health. Precursor to glycine and plays role in collagen formation.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every L-Threonine product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Thorne Amino Complex - Travel Packs - Berry | 85 A- | $1.20 |
| 2 | Thorne Amino Complex - Travel Packs - Lemon | 85 A- | $1.20 |
| 3 | Thorne Amino Complex - Berry | 84 A- | $1.47 |
| 4 | Thorne Amino Complex - Lemon | 84 A- | $1.47 |
| 5 | Pure Encapsulations Essential Aminos | 81 A- | $0.31 |
| 6 | Thorne Amino Complex | 80 A- | $1.20 |
| 7 | Pure Encapsulations Amino-NR | 79 B+ | $0.78 |
| 8 | Double Wood Essential Amino Acid Supplement | 77 B+ | $0.27 |
| 9 | Pure Encapsulations Amino Replete | 73 B+ | $0.88 |
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-Threonine should I take?
The typical range is 500-2000 mg daily. Safe long-term
When should I take L-Threonine?
With meals. Best with food.
Which form of L-Threonine is best?
Capsule — Common form. Other forms in the catalog: Powder.
Is L-Threonine safe?
Commonly reported: Well tolerated. Serious warnings: None at normal doses. No significant concerns
Which L-Threonine supplement scores highest?
Thorne Amino Complex - Travel Packs - Berry, at 85/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Primary uses
- Protein synthesis
- Immune support
- Collagen formation
- Gut barrier function
How it works
- Converted to glycine for collagen synthesis
- Supports mucin production in gut
- Required for antibody production
- Component of tooth enamel
Dosage
- Typical range
- 500-2000 mg daily
- Timing
- With meals
- With food
- Best with food
- Duration
- Safe long-term
- Special populations
- Those with low protein intake
Forms
- Capsule
- Powder
Safety
Common side effects
- Well tolerated
Contraindications
- None known
Products containing L-Threonine
Top-scoring supplements in our catalog that list L-Threonine on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Essential amino acid with established physiological roles
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.