DHEA is transformed into DHEA-S by sulfation at the C3β position via the sulfotransferase enzymes SULT2A1 and to a lesser extent SULT1E1 .    This occurs naturally in the adrenal cortex and during first-pass metabolism in the liver and intestines when exogenous DHEA is administered orally. [ citation needed ] Levels of DHEA-S in circulation are approximately 250 to 300 times those of DHEA.  DHEA-S in turn can be converted back into DHEA in peripheral tissues via steroid sulfatase (STS).  
Health records shall contain the date the lot was established (if using the unique lot method), the first date the animal(s) may be shipped for slaughter considering the requirement for at least a 180 day recorded history prior to slaughter, the unique identifier, as well as record entries that indicate the date the illness was noticed, the details of the illness, the number of animals affected and date the illness was resolved. Each record event entry shall be accompanied by the initials of the person making the entry and date/time of the entry.