Hydrocodone is the active ingredient in Vicodin and lortab. These two medications are a combination of Hydrocodone and another ingredient that stregthens the Hydrocodone. The other ingredient in these two medications (which I presume its one or the other that you are taking) is acetamenophen or tylenol. this combination does not thin the blood, however I will warn you about other medications extremely similar to Hydrocodone w/tylenol that will thin your blood. Percodan is a combination of Oxycodone W/asprin. and like the post before me said, asprin is a blood thinner.If you are worried about blood thinning do not take percodan. Percocet (oxycodone w/acetamenophen) on the other hand is fine.