Amino Acid
L-Ornithine α-Ketoglutarate
Also known as: OKG, Ornithine alpha-ketoglutarate, Ornithine AKG, L-Ornithine AKG
L-Ornithine α-Ketoglutarate is a salt combining the amino acid L-ornithine with α-ketoglutarate, theoretically supporting protein synthesis and muscle recovery. Limited clinical evidence exists for its efficacy in healthy populations, with most data from small or older studies.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Common questions
How much L-Ornithine α-Ketoglutarate should I take?
The typical range is 5–10 g daily. Typically taken for 4–8 weeks during training phases; longer-term safety data is limited
When should I take L-Ornithine α-Ketoglutarate?
Post-workout or with meals. May be taken with or without food; taking with carbohydrate or protein may enhance amino acid utilization.
Which form of L-Ornithine α-Ketoglutarate is best?
Powder. Other forms in the catalog: Capsule.
Is L-Ornithine α-Ketoglutarate safe?
Commonly reported: Nausea or mild gastrointestinal upset, Generally well tolerated at recommended doses.
Which L-Ornithine α-Ketoglutarate supplement scores highest?
Pure Encapsulations Growth Hormone Support, at 77/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Primary uses
- Muscle protein synthesis
- Post-exercise recovery
- Wound healing support
- Nitrogen metabolism
How it works
- Provides ornithine precursor for polyamine synthesis and collagen formation
- Supplies α-ketoglutarate to support amino acid metabolism and TCA cycle function
- May enhance arginine synthesis through the urea cycle
Dosage
- Typical range
- 5–10 g daily
- Timing
- Post-workout or with meals
- With food
- May be taken with or without food; taking with carbohydrate or protein may enhance amino acid utilization
- Duration
- Typically taken for 4–8 weeks during training phases; longer-term safety data is limited
- Special populations
- Safety in pregnant/nursing women, children, and those with urea cycle disorders not well established
Forms
- Powder· 70/100
- Capsule· 70/100
Safety
Common side effects
- Nausea or mild gastrointestinal upset
- Generally well tolerated at recommended doses
Contraindications
- Urea cycle disorders or arginine/ornithine metabolism conditions
- Use with caution in individuals with liver dysfunction
Products containing L-Ornithine α-Ketoglutarate
Top-scoring supplements in our catalog that list L-Ornithine α-Ketoglutarate on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Some clinical studies show modest benefits for wound healing and post-surgery recovery in stressed populations, but evidence in healthy athletes is limited and inconsistent. Most studies are small, older, or conducted in surgical/hospitalized patients rather than healthy supplement users.
Grade C: Mostly observational or small trials; mechanism is plausible but unproven at scale.
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.