Positives

• A long-hauler with ectopic heartbeats and gut dysbiosis (extremely high hydrogen-sulfide–producing bacteria on stool testing) included 200 mcg molybdenum in a 6-week “kill phase” protocol to support sulfite detoxification alongside allicin, lactoferrin, and a restricted low-sulfur diet Reddit.
  
  

Negatives

• The Linus Pauling Institute notes overt molybdenum deficiency is essentially absent in healthy people eating a varied diet, so supplementation typically corrects no real deficit; meanwhile excess molybdenum can impair copper absorption and produce a secondary copper deficiency. Lpi.
• An Armenian population consuming 10-15 mg/day of molybdenum from food showed gout-like joint symptoms, and the tolerable upper intake level is 2 mg/day for adults; high-dose supplements can therefore raise uric acid and trigger gout flares in susceptible patients. Nutritionsource.
• The NIH ATSDR toxicology profile describes molybdenum-copper antagonism in detail and warns of nausea, stomach upset, and altered bowel habits at higher doses, with copper depletion the more clinically significant long-term concern. NIH.

Hurdles & Side Effects

• Community discussion highlighted that high unbound copper can deplete molybdenum, and that molybdenum supplementation can in turn deplete copper — patients considering supplementation were advised to test copper levels first to avoid worsening irregular heartbeats Reddit.
  
  
• A long-hauler who recovered from neuro-type Long COVID using high-dose thiamine (B1) listed molybdenum as one of the supporting minerals alongside iodine and selenium, noting that B1 was the key but cofactors were “just as important” for the protocol to work Reddit.