This Source Naturals product delivers a robust 500 mg of Vitamin B1, likely in a standard water-soluble form such as Thiamine Hydrochloride or Mononitrate. This high dosage is typical for individuals with significant thiamin requirements, those addressing deficiencies, or seeking intense support for metabolic and neurological functions. While the high concentration provides ample thiamin, the water-soluble nature of the form may limit its overall absorption efficiency compared to fat-soluble alternatives like Benfotiamine, potentially leading to a higher rate of excretion. However, for a standard B1 supplement, it offers a very good quantity at a competitive price.