Arginine hydrochloride is a salt of L-arginine made to enhance solubility and stability. Its absorption matches other forms. Pre-workout products often include it because it may boost nitric oxide and blood flow.
People often take it as a single dose before a workout to improve muscle pump and performance, but trials show mixed outcomes. The salt's acidity can upset the stomach, particularly at high doses or without food.
Taking it with food or a light snack eases stomach irritation. Doses are typically acute, a single pre-workout serving, rather than daily. High chronic doses raise the chance of side effects.