A methionine residue oxidizes
The microscopic p K a values of the thiol group of BSH were determined as p K a = 7.97 when the amino group of the Cys is protonated and as p K a = 9.55 in the presence of the deprotonated amino group of Cys (Sharma et al., 2013)
PubMed DOI Seiwerth S, Brcic L, Vuletic LB, et al
Immune Support This amino acid derivative strengthens white blood cell function by maintaining optimal glutathione levels required for immune response
Even if I had, a listing does not in any way denote approval of the establishment or its products by FDA. Besides, the FDA has a very loose policy with regards to what it deems to be low risk general wellness products. Many such products end up registered with the FDA as disposable hot or cold packs or something equally mundane, while its users claim health benefits that have never been evaluated by the FDA
Autoimmunity Reviews, 8(8), 697701