Supplement Label Index

Arginine Silicate Inositol Complex (Nitrosigine-type) vs. L-Arginine Pyroglutamate

Among 1,304 on-market l-arginine products with an identifiable primary form, 7.2% use Arginine Silicate Inositol Complex (Nitrosigine-type) (94 products) and 4% use L-Arginine Pyroglutamate (52).

Arginine Silicate Inositol Complex (Nitrosigine-type)L-Arginine Pyroglutamate
Quality tierUnratedUnrated
L-Arginine by weight—57.4%
Share of market7.2%4%
On-market products9452
Median declared dose—
574 mg
middle half: 354.15–861
Most common brandsPS ProSupps, MuscleTech Performance Series, Axe & Sledge SupplementsSource Naturals, Anabolic Warfare, Higher Nature

Doses are declared per serving in mg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).

Why Arginine Silicate Inositol Complex (Nitrosigine-type) is unrated

Branded complex with its own small trials (e.g. acute vasodilation and cognition studies); no comparison against other arginine forms was verified.

Why L-Arginine Pyroglutamate is unrated

No head-to-head human bioavailability or efficacy comparison of this form was located in PubMed searches.

Tiers summarize published comparative bioavailability or outcome evidence for each form (see methodology). This page describes the market; it is not a recommendation to take either form. Talk to a clinician about what's right for you.

Other l-arginine comparisons