Comparison guide
Which arginine should you take?
All three deliver arginine, which is heavily broken down in the gut and liver before it reaches your blood. The bonded forms add silicate or alpha-ketoglutarate and a higher price, but none has shown better training results — and L-citrulline raises blood arginine more effectively than any of them.
The options, compared
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| L-Arginine | Moderate evidence | Modest blood-pressure lowering | The only form here with moderate evidence, for a few mmHg of blood-pressure reduction at 4–6 g a day or more. Pump and performance claims are weak, and it must not be used after a recent heart attack. | View |
| Arginine Silicate (Nitrosigine) | Limited evidence | Not worth the premium | Raises blood arginine more than arginine alone, but the trials are small, mostly manufacturer-funded and measure cognition or vasodilation, not strength or muscle gain. | View |
| AAKG (Arginine Alpha-Ketoglutarate) | Limited evidence | Skip it | Raises plasma arginine but not nitric oxide markers or blood flow, and 12 g a day for 8 weeks showed no advantage over placebo for peak power or body composition. About half of each scoop is alpha-ketoglutarate, and typical 1–3 g label doses are below anything tested. | View |
Our verdict
If you want arginine, plain L-arginine is the default, mainly for blood pressure. For a pre-workout or a reliable rise in blood arginine, L-citrulline at 3–6 g a day is the better-supported choice; arginine silicate and AAKG cost more without clearly better results. Avoid every form after a recent myocardial infarction, and check with a doctor if you take blood-pressure drugs, nitrates or PDE5 inhibitors.