The nine protein building blocks the body cannot make, taken in free form for faster absorption. Strongest evidence where muscle is under threat: bed rest, after joint surgery, or older adults whose walking has slowed. Also less liver fat. Little added benefit when protein intake is already generous. Safety over weeks to months shows nothing notable; longer-term effects untested. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Estimated glomerular filtration rate | Above 90 mL/min/1.73 m² | Sets whether the added nitrogen load matters |
| Blood urea nitrogen | 10–16 mg/dL | Direct readout of the nitrogen being cleared |
| Serum creatinine | 0.7–1.0 mg/dL (men), 0.6–0.9 mg/dL (women) | Second kidney marker, less diet-sensitive than urea |
| Fasting insulin | Below 6 µIU/mL | Earliest marker of the metabolic concern |
| HOMA-IR | Below 1.5 | Quantifies insulin resistance from fasting values |
| HbA1c | 5.0–5.4% | Three-month glucose average, tracks the diabetes-risk question |
| Homocysteine | Below 9 µmol/L | Tracks the methionine content of the blend |
| Alanine aminotransferase | Below 25 U/L (men), below 20 U/L (women) | Liver enzyme; the liver-fat benefit should lower it |
| Appendicular lean mass index | Above 7.0 kg/m² (men), above 5.5 kg/m² (women) | The muscle outcome the supplement targets |
| Grip strength | Above 27 kg (men), above 16 kg (women) | Cheapest validated proxy for whole-body strength |
| Six-minute walk distance | Above 400 m | The endpoint that moved in trials |
Cadence: Baseline panel before starting; kidney markers, HbA1c and homocysteine repeated at 3 months, then every 6 to 12 months; grip strength and the six-minute walk repeated at 12 weeks and again at 6 months.