Amino Acid
L-Aspartic Acid
Also known as: Aspartic acid, L-Aspartate, Aspartate, DAA (when discussing D-aspartic acid context)
L-aspartic acid is a non-essential amino acid involved in protein synthesis, neurotransmitter function, and energy metabolism. Limited direct evidence supports supplementation for athletic performance or testosterone enhancement in healthy individuals.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every L-Aspartic Acid product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Nutricost D-Aspartic Acid Capsules | 86 A- | $0.38 |
| 2 | Nutricost Testosterone Complex Capsules | 84 A- | $0.57 |
| 3 | Pure Encapsulations Tribulus Formula | 84 A- | $1.47 |
| 4 | Country Life Thyro-Max Support | 79 B+ | $0.67 |
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-Aspartic Acid should I take?
The typical range is 500 mg - 3 g daily. Safe for long-term use as part of normal protein intake; no established protocol for supplemental dosing
When should I take L-Aspartic Acid?
Any time; often taken with meals or as part of amino acid blends. No specific requirement; can be taken with or without food.
Which form of L-Aspartic Acid is best?
Powder. Other forms in the catalog: Capsule, Tablet.
Is L-Aspartic Acid safe?
Commonly reported: Generally well-tolerated at typical doses, Minimal side effects reported in literature, High doses may cause gastrointestinal distress.
Which L-Aspartic Acid supplement scores highest?
Nutricost D-Aspartic Acid Capsules, at 86/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Primary uses
- Protein synthesis support
- Energy metabolism
- General amino acid supplementation
How it works
- Incorporated into proteins during translation
- Precursor for neurotransmitters (aspartate, glutamate)
- Substrate in energy-producing metabolic pathways
- Component of purines and pyrimidines for nucleotide synthesis
Dosage
- Typical range
- 500 mg - 3 g daily
- Timing
- Any time; often taken with meals or as part of amino acid blends
- With food
- No specific requirement; can be taken with or without food
- Duration
- Safe for long-term use as part of normal protein intake; no established protocol for supplemental dosing
- Special populations
- Generally safe for most populations; pregnant/nursing women should consult healthcare providers
Forms
- Powder· 70/100
- Capsule· 70/100
- Tablet· 70/100
Safety
Common side effects
- Generally well-tolerated at typical doses
- Minimal side effects reported in literature
- High doses may cause gastrointestinal distress
Contraindications
- Phenylketonuria (PKU) — use with medical supervision
- Individuals with kidney disease should consult healthcare provider before supplementing
Products containing L-Aspartic Acid
Top-scoring supplements in our catalog that list L-Aspartic Acid on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
L-aspartic acid is naturally occurring and essential for normal physiology, but direct supplementation evidence in healthy humans is limited. Most research conflates it with D-aspartic acid (DAA), which has been studied more heavily with mixed results for testosterone. Insufficient RCT data to support specific performance claims.
Grade C: Mostly observational or small trials; mechanism is plausible but unproven at scale.
Cited research for L-Aspartic Acid
Clinical studies referenced across Formulate guides that mention l-aspartic acid. Each links to the full study page with PubMed source + the guides that cite it.
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.