All steroids will negatively impact cholesterol levels. They will lower your HDL and raise your LDL.
The best thing you can do to lower cholesterol levels is to follow a cholesterol friendly diet - low in saturated fats and refined sugars, and high in omega 3 fatty acids -
and to regularly incorporate hard cardio that really gets your heart rate up into your training program.
A good overall cholesterol support supplement certainly won't hurt either. Check out N2guard from n2bm.com. N2guard contains 43 ingredients designed to detox the body and keep cholesterol levels optimal.
Keep an eye on your cholesterol levels. If it gets bad, go to your doctor and get him to write you a cholesterol medication. You don't need to use the cholesterol medication forever. You can stop using it once your cycle is over.