So the side effects of Pentasa include the following
Fever, rash, nausea, loss of appetite, diarrhea, abdominal pain, hives, renal dysfunction, liver dysfunction, jaundice, hyperamylasemia, nephrosis, leukopenia, hypersensitivity lung injury, pancreatitis, myocarditis, pericarditis, pleurisy, myalgia, joint pain, abdominal distention, stomatitis, hair loss
Some of the commenters have seen symptoms of hair loss, but I have not experienced any side effects during the two years I have been on Pentasa. It seems that it depends on the individual.