L-Ornithine
Endogenous non-protein amino acid and urea-cycle intermediate produced from arginine. Supplemental L-ornithine is metabolized into citrulline, glutamate-family amino acids, and polyamine precursors; a plasma curve is therefore an effective amino-acid-pool estimate, not a conventional drug concentration. Human efficacy evidence for fatigue, stress, or sleep is limited and often industry-sponsored. Long-lasting hyperornithinemia can injure the retina in susceptible metabolic disease.
Projected serum levels — 1k mg, once daily
Maintenance schedule: 1k mg once daily (oral).
Modeled steady state after ~1 days: peak ≈ 332 mg, trough ≈ 0.014 mg body load. Population-based estimate over 15 days for a 1k mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.
Key facts
- Category
- Amino Acid
- Route modeled
- Oral
- Model confidence
- inferred
- Half-life
- 1.5 h
- Common dose
- 1k mg
- Suggested maximum
- 12k mg/day
- Reference dose range
- 400–12k mg (single dose)
- Suggested cadence
- once daily
- Validated against
- 10k mg oral — Cmax 79.3 mg/L at 1 h
Research behind this entry
-
Pharmacokinetics of arginine and related amino acids
Review of human arginine-family amino-acid kinetics found return toward baseline within 5-8 hours and urinary excretion below 5% of dose. Oral doses near 10 g produced approximate total ornithine Cmax around 600…
-
Ornithine and its role in metabolic diseases
Mechanistic review maps ornithine's roles in the urea cycle, synthesis of citrulline, proline and polyamines, and disorders involving ammonia or ornithine handling. It provides biochemical context and candidate…
-
Safety assessment of L-ornithine oral intake in healthy subjects
Systematic review identified 22 oral studies in healthy people. The largest reported daily L-ornithine hydrochloride dose was 14,025 mg and the authors estimated a 12,000 mg/day no-observed-adverse-effect level;…
-
Retinal risks of high-dose ornithine supplements
Review distinguishes transient oral elevations from chronic hyperornithinemia. Short exposure was not associated with retinal lesions, whereas sustained concentrations above roughly 600 micromol/L in gyrate atrophy were…
5 published studies referenced in the app, each with a plain-language summary.