A cheap amino acid taken by mouth during chemotherapy or radiation. It measurably reduces severity of mouth ulceration, diarrhea and radiation skin injury, and infections after cancer surgery. Nerve damage and muscle wasting benefits did not hold up. Tumors consume glutamine heavily, and whether supplementing feeds them stays unresolved. Infused glutamine carries harm signals that swallowed glutamine does not. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Blood ammonia | 15–35 µmol/L | Detects the nitrogen load glutamine adds |
| Blood urea nitrogen | 10–16 mg/dL | Tracks total nitrogen handling |
| Creatinine and eGFR | eGFR above 60 mL/min/1.73 m² | Screens for the kidney injury reported at 18 grams daily |
| ALT and AST | Below 25 U/L for both | Detects liver stress limiting ammonia clearance |
| Albumin | 4.2–5.0 g/dL | Reflects the protein reserve glutamine supports |
| C-reactive protein | Below 1.0 mg/L | Tracks the inflammation glutamine is proposed to reduce |
| Absolute lymphocyte count | 1.5–3.0 × 10⁹/L | Immune recovery between treatment cycles |
| Plasma glutamine | 500–750 µmol/L | Confirms the depletion supplementation targets |
| Disease-specific tumor marker | No established target for this purpose; track the direction of change from the individual's own pre-treatment value | Watches for any signal of accelerated progression |
Cadence: Baseline before starting; metabolic panel and blood count rechecked at four weeks, then before each subsequent chemotherapy or radiation cycle, with ammonia repeated at four weeks where there is liver involvement or reduced filtration; a single check at three months after treatment ends.