I have always used in during cold and flu but i don’t think it makes much of a difference for me. To be honest, home remedies work much better. Good thing is that it doesn’t make you sleepy.

It's help me with my cold and flu ..it taste better then another cough syrup . I mostly like to drink it during day time . I usually take this medication when im dealing with a heavy cough

I’ve been using the DayQuil and NyQuil Cold & Flu liquid co-pack, and it works really well for flu and cold symptoms. My husband needed to take NyQuil last night and was able to sleep soundly, waking up feeling much better this morning. Interestingly, it has the opposite effect on me—NyQuil actually keeps me awake instead of helping me sleep. The taste isn’t great, but it’s tolerable. Vicks products usually have a strong taste and scent, which I actually like because it makes me feel like they’re working better. It’s worth it to keep in the medicine cabinet. Overall, very effective for symptom relief, though results may vary depending on the person. I’d give it 4/5 stars.