Caution: Individuals who are sensitive to sulphites (often used as preservative) also may react to MSM and DMSO. This is usually due to a deficiency of molybdenum and can be overcome with supplementation (try 500 mcg).

https://www.health-science-spirit.com/Healing_the_Body/MSM-and-DMSO.html

https://en.m.wikipedia.org/wiki/Molybdenum

https://en.m.wikipedia.org/wiki/Molybdenum_deficiency

https://en.m.wikipedia.org/wiki/Molybdenum_cofactor_deficiency

https://en.m.wikipedia.org/wiki/Molybdopterin