<Tr> <Td> Bioavailability </Td> <Td> Oral: very low (due to extensive first pass metabolism) </Td> </Tr> <Tr> <Td> Protein binding </Td> <Td> 97.0--99.5% (to SHBG and albumin) </Td> </Tr> <Tr> <Td> Metabolism </Td> <Td> Liver (mainly reduction and conjugation) </Td> </Tr> <Tr> <Td> Biological half - life </Td> <Td> 2--4 hours </Td> </Tr>

Where does the testosterone in androgel come from