My experience with Zyrtec started out great. It had a noticeable effect in reducing my mucus. Less mucus = less fatigue, more focus. I found it much easier to sit through long TV shows and concentrate on work.
However, on the weekend of the 19th, things took a dive. I developed some thick mucus blockage that got so bad that by Monday, I had to resort to my old methods (drinking lots of hot water, inhaling humidifier steam, sitting on hot water to release gas and induce bowel movement) to get it out. They helped, but now enough; as of today, I still have not fully cleared the blockage.
After the thick blockage developed, Zyrtec no longer felt effective. Once again, I had to deal with regular haziness, fatigue, and regurgitation. Admittedly, Zyrtec did mitigate symptoms more than Mucinex. Without the H1 blocker, I probably would have suffered a nighttime seizure.
Overall, I feel that Zyrtec works for treating the symptoms, but does not tackle the root of the problem. I also can’t shake the growing suspicion that it suffers the same problem as Mucinex in that it obstructs the clearing of the blockage.