Thiamine Hydrochloride (Thiamine HCl)
Thiamine Hydrochloride (Thiamine HCl) is a tier 1 form of Thiamine (Vitamin B1), used in 5,547 on-market products and providing 78.7% elemental thiamine (vitamin b1) by weight.
Basis: thiamine cation MW 265.36 / thiamine HCl MW 337.26 (both confirmed PubChem formulas)
Why this tier: Both HCl and mononitrate are salts of the same thiamine cation and both are GRAS vitamin sources, so they are treated as equivalent on chemical grounds; no human head-to-head bioavailability trial was located. HCl's higher water solubility is used in liquid/injectable products.
Source: 21 CFR 184.1875 (thiamine hydrochloride); 21 CFR 184.1878 (thiamine mononitrate). The EFSA opinions PMC12035548/PMC11979709 are animal-feed authorisation opinions, not human bioavailability evidence.