Hello and thanks for your question!
If you are mostly having trouble with congestion, it is very important that you pick the correct NyQuil product since only some of them contain a decongestant.
For example, the original NyQuil formula does not have a decongestant in it! It only contains the following three active ingredients:
Acetaminophen is a pain reliever/fever reducer. It is also the active ingredient in Tylenol. When it comes to its use in treating a cold, it will help with minor aches and pains and can also lower your temperature if you have a fever.
Dextromethorphan is a cough suppressant and should reduce both the frequency of cough and the severity of it.
Lastly, doxylamine is a sedating antihistamine. It (in addition to the alcohol that NyQuil contains) is what makes you tired. Antihistamines also help to reduce the severity of many cold symptoms, including a runny nose, watery eyes and postnasal drip. They may help slightly in treating nasal congestion since they can reduce inflammation and have a 'drying' effect (i.e. reduce mucus secretion), but drugs that are specifically classified as decongestants are far more effective.
If you want a NyQuil product that has a decongestant, be sure to pick up NyQuil Severe. NyQuil Severe contains four active ingredients:
As you can see, NyQuil Severe simply contains one additional ingredient, the nasal decongestant phenylephrine.
Studies show that phenylephrine likely isn't as effective as the other oral decongestant available over the counter, pseudoephedrine, but it can still be a good option to use to help with your stuffy nose.
So, the overall point is that original NyQuil won't help to clear your congestion since it doesn't contain a decongestant. NyQuil Severe, on the other hand, is a perfectly fine option since it does contain a decongestant (phenylephrine).
Other Options For Congestion
If nasal congestion is your only concern here, there are several other alternative options available that could effectively treat it.
First and foremost, the oral decongestant pseudoephedrine (also available as the brand name Sudafed) will likely be your most effective option.
While it is available over the counter, it must be purchased at the pharmacy and you will have to show identification for it (pursuant to the Combat Methamphetamine Epidemic Act). It works very well to reduce congestion but be sure to ask your doctor about its use first if you have high blood pressure or a history of cardiac issues.
Other over the counter options to treat congestion include:
- Nasal steroids (e.g. Flonase, Nasonex)
- Topical decongestant, such as Afrin and Neo-Synephrine
- Nasal steroids are great at reducing inflammation and congestion over the long-term but don't do a great job of providing immediate relief.
Topical decongestants, like Afrin, begin to work in only a few minutes, but they can only be used for a maximum of two to three days before rebound congestion can occur.
NyQuil (the original formula) does not contain a decongestant and therefore, won't be very effective in treating nasal congestion. NyQuil Severe however, does contain a decongestant, phenylephrine. Therefore, if you are looking to take a NyQuil product that will treat nasal congestion, be sure to choose NyQuil Severe.