Agmatine Sulfate
Agmatine is a decarboxylation product of arginine sold as a supplement and marketed for nitric-oxide 'pump', neuropathic pain and mood. Its proposed vasodilatory role rests on modulation of nitric-oxide synthase and imidazoline receptors, but human evidence is thin and mostly limited to small pain studies; ergogenic and erectile claims are essentially anecdotal.
01 Overview
Agmatine is formed by decarboxylation of L-arginine and interacts with several targets — imidazoline receptors, alpha-2 adrenoceptors, NMDA receptors and nitric-oxide synthase (which it can both inhibit and modulate). In supplement marketing it is presented as a nitric-oxide/'pump' agent and a neuromodulator, and a small body of human work supports a role in neuropathic pain.
Most of the mechanistic data are preclinical, and the pump and erectile claims are extrapolated rather than demonstrated in humans. It is a lightly studied supplement; it is generally reported as well tolerated at gram doses, with occasional GI upset, but its long-term safety is not well characterised.
02 Mechanism
Arginine metabolite that modulates nitric-oxide synthase, imidazoline and alpha-2 adrenergic receptors and NMDA receptors; net vascular effect in humans is not well established.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Supplement | 0.5–1.5 g/day | Oral | Common supplement range; not established by trials for pump or ED. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Neuropathic pain reductionSome small human and animal data suggest benefit in neuropathic pain; not an ED/pump outcome. | small | Preclinical | |
| Claimed nitric-oxide 'pump'Marketed for vasodilation and pump, but human vascular evidence is lacking. | unproven | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Gastrointestinal upsetNausea, diarrhoea or bloating reported at higher doses. | Mild | Uncommon | Anecdotal | |
| Uncharacterised long-term safetyChronic human safety data are lacking given multiple receptor targets. | Moderate | Unknown | Unconfirmed |