Supplement analysis backed by scientific evidence · PT

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Limited evidencePhysical performance

AAKG (Arginine Alpha-Ketoglutarate)

AAKG is L-arginine bonded to alpha-ketoglutarate, sold on the promise of a bigger nitric oxide "pump" than plain arginine. Controlled trials find it raises plasma arginine but does not improve strength, endurance, or blood flow — citrulline is the better-supported pre-workout vasodilator.

What the science says

  • Does not improve strength or muscular endurance Limited evidence

    In the largest controlled trial, 12 g/day AAKG for 8 weeks in 35 resistance-trained men raised 1RM bench press modestly but showed no advantage over placebo for Wingate peak power, and produced no change in body composition. A 2012 acute study giving 3,000 mg AAKG 45 minutes before training in trained and untrained men found no improvement in bench press or leg press reps to failure in either group.

  • Raises plasma arginine but not nitric oxide markers or blood flow Limited evidence

    Seven days of AAKG (12 g/day) significantly increased plasma L-arginine but did not increase nitrite/nitrate (NOx), did not increase brachial artery blood flow after resistance exercise, and did not reduce asymmetric dimethylarginine. Oral arginine is heavily degraded by intestinal and hepatic arginase, which is why citrulline — which bypasses first-pass arginase and raises plasma arginine more effectively — outperforms it.

  • The alpha-ketoglutarate half adds no proven benefit Limited evidence

    No published human trial has compared gram-for-gram AAKG against an equivalent dose of plain L-arginine for performance outcomes. The AKG moiety is a Krebs cycle intermediate with its own emerging longevity literature, but at AAKG doses roughly half the powder is AKG, meaning a 6 g scoop delivers only about 3 g of arginine.

Dosage & safety

Studied doseStudies used 3,000 mg acutely pre-exercise (no effect) or 4 g three times daily (12 g/day total) for 7-56 days. Typical label doses of 1-3 g per scoop in pre-workout blends are below anything ever tested. If you want a nitric-oxide pre-workout with real data, 6-8 g citrulline malate or 3 g L-citrulline has far stronger support.
SafetyGenerally well tolerated; 12 g/day for 8 weeks produced no clinically meaningful changes in blood chemistry, lipids or blood pressure. Common complaints are GI upset, bloating and diarrhea at multi-gram doses. Arginine can lower blood pressure additively with antihypertensives and PDE5 inhibitors, and may reactivate herpes simplex in susceptible people (arginine:lysine ratio). Avoid after recent myocardial infarction — a trial of high-dose arginine in post-MI patients was stopped early for excess mortality. Not banned in sport.

Scientific references

Where to buy

NutraBio, AAKG, 1.1 lb (500 g)

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