Note that high levels of Neu5Gc are also found in caviar vs. 0 in butter: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4299224/table/t01/ The values in the table are based on grams and NOT serving size. Table above is from this 2015 article: https://pubmed.ncbi.nlm.nih.gov/25548184/

I’m no chemist, but by my math they used high doses. For glycine (1.33 mmol/kg/day) = 1.33 x 75.07 = 99.8431 mg/kg. So for a weight of 175lb. = 79.4kg = 7,927 mg/day. And cysteine (0.81 mmol/kg/day) = 0.81 x 121.16 = 98.1396 mg/kg = 7,792 mg/day [vs. NAC might be different; not clear from article]. vs. I believe that Dr. Rhonda Patrick was taking only 1200mg NAC at one time. [Disclaimer: do NOT trust my math and use these doses!]