<p>Agavins are highly branched neo-fructans, extracted from Agave plants, use as prebiotic supplement by itself or in the elaboration of functional foods. In the last years, agavins have been gaining popularity into prebiotic supplements market, due to the growing scientific evidence, at preclinical and clinical level, highlighting its health benefits. However, the tendency to reduce cost and maximize profits, by some traders, has led to agavins adulteration. In the present study, two chromatography techniques (HPTLC and HPAEC-PAD) as well as Fourier transform infrared spectroscopy (FTIR) were used to evaluate the authenticity of commercial agavins. Combination of these analytical tools allowed the identification of authentic commercial brands. Of note, the majority of evaluated commercial agavins were found to be adulterated with low-cost polysaccharides such as polydextrose, maltodextrin, and/or oligofructose. Partial or total adulteration of prebiotic agavins compromises their quality, security, functionality, and efficacy, which may present serious metabolic risks for specific consumers, such as diabetics and/or obese. Hence, regulatory authorities should intervene to assure the authenticity of commercial agavins as a prebiotic supplement.</p>