That's a great question. It is a known side effect that isotretinoin/accutane can increase cholesterol levels, this is why routine blood tests are done! Diet (particularly in close proximity to the time of the blood draw) can also increase the results on blood tests. The reason for your levels to increase could be one, the other, or both.As for what to do, this is a common problem with several options. The easiest thing to do is change your diet and re-do the test. If your diet was unusually fatty the day before, returning to your normal diet might fix everything. Certain brands of isotretinoin require you to take it with a fatty meal so your body can absorb the medicine. Other brands come with a coating that help proper absorbtion, so you don't need to worry about meals and timing. Check with your doctor to find out which you have and follow his/her instruction on diet. If the numbers are still high, it is possible for you to stay on the medicine, just at a lower dose. This is commonly done and only slightly decreases the effectiveness of the treatment (as measured by the number of patients who need to go on the medicine a second time).It is important to note, one type of fat in the blood called triglycerides, can be so elevated that it can cause serious harm (inflammation of the pancreas, known as acute pancreatitis). This is one of the reasons why close follow up with your doctor when on a powerful medicine like isotretinoin is key. Best of luck!