There is a large selection of L-arginine supplements. However, often the dosage is insufficient. In addition, it’s easy to become confused by the different variants of this amino acid, listed either as:
• L-arginine HCL
L-arginine base or L-arginine HCL?
Although L-arginine is an amino acid, it isn’t acidic. Thus, chemists classify pure L-arginine as L-arginine base. Although soluble in water, L-arginine base then develops an unpleasant odor and a soapy consistency characteristic of a base. L-arginine HCL binds L-arginine with the salt of hydrochloric acid, creating a stable bond.
Compared with L-arginine base, L-arginine HCL has other advantages:
• there is less odor,
• tasteless and
• more water soluble
Dosage indication of L-arginine
The two different forms of L-arginine indicate different dosages of this amino acid.
- A high quality supplement specifying “L-arginine 1,000 mg” refers to pure L-arginine content.
- A high quality supplement specifying “L-arginine HCL 1,000 mg” refers to the amount of L-arginine hydrochloride. The pure L-arginine content is only between 70 and 83% of the total.
Thus, the two products in this example have different amounts of L-arginine. However, if a supplement lists L-arginine, it doesn’t necessarily mean that L-arginine base is used. To determine which form of L-arginine is in the product, always refer to the list of ingredients. All materials must be specified in the chemically correct form for all dietary supplements. When the L-arginine is present as L-arginine HCL, the content or the dosage should be judged according to the converted pure L- arginine content.