Short Answer: It could be byproducts of any of the three amino acids that make up the glutathione molecule, which include the individual amino acids, ammonia, hydrogen sulfide, sulfite, and propionyl CoA, or it could be microbial metabolites of glutathione produced in the gut. The full answer contains seven hypothesis-driven tests that can be done at home to determine the cause. This is a clip from a live Q&A session open to CMJ Masterpass members. In addition to this episode, you can access two other free samples using this link: https://chrismasterjohnphd.substack.com/p/questions-on-statins-versus-sulfur In that batch of free episodes you will also find the answers to these questions: Statins Vs. Sulfur for Heart Disease Why Plasma Zinc is the Best Marker of Zinc Status If you want to become a Masterpass member so you can participate in the next live Q&A, or so you can have access to the complete recording and transcript of each Q&A session, you can save 10% off the subscription price for as long as you remain a member by using this link to sign up: https://chrismasterjohnphd.substack.com/qanda Learn more about the Masterpass here: https://chrismasterjohnphd.substack.com/about This snippet is from the October 12, 2022 AMA. The full recording and transcript is reserved for Masterpass members. Here is a preview of what’s included: NADH vs NMN vs NR An unexplained rise in urine ketones Spreading out calcium across meals What should we have in our cold season cabinet? What besides diet could cause my high morning glucose on a CGM? Will some older people benefit from supplementing carnitine? What do I think about the CGM fad? Could my low triglycerides be cholestasis? Why limit the dose of cod liver oil? Why do I always feel better when my sulfur problems are worse? Should I use one lab’s reference range with another lab’s results? Is it safe to eat roasted potatoes? How much weight should I give genetic SNPs in my nutrition? High RBC magnesium but low serum: what could it mean? Burning in the stomach: what could it be? Should I treat low plasma amino acids by supplementing them? Why would MK-4 cause heart palpitations? Here’s a link to the full AMA: https://chrismasterjohnphd.substack.com/p/recording-and-transcript-of-the-october