While there’s some evidence of a connection between NyQuil and erectile dysfunction (ED) because of its active ingredients, there’s no known direct link between the drug causing the condition.

NyQuil is an over-the-counter (OTC) medication that’s used to treat symptoms of a cold or flu, such as a runny nose, coughing, and pain.

But its active ingredients can cause a wide range of side effects. These include drowsiness, changes in your heart rate, and headaches. There’s also some evidence that the active ingredients may cause erectile dysfunction (ED).

Read on to learn more about why NyQuil might be responsible for ED, other medications that can cause ED, and the side effects of NyQuil that might require getting medical help.

There’s no direct evidence that NyQuil itself can cause ED. No studies or reviews have ever reached any conclusions about a link between the two.

But NyQuil is made up of three active ingredients that each have a connection to the causes and symptoms of ED:

A 2017 study discusses the link between common analgesics like acetaminophen used to treat chronic pain and ED.

The authors suggest that the link may result from analgesics disrupting the communications between your brain and the nerves and hormones that your brain triggers to help you get an erection when you’re aroused. They note that taking analgesics for a long time can also lower your natural testosterone levels.

Both of these effects can lead to ED. In addition, this finding was also correlated by an improvement in ED symptoms when participants in the study were given medications for ED and testosterone gel to counteract these effects.

There’s less compelling evidence linking DXM directly to ED.

Clinical trials involving 162 people who tried an antidepressant called Auvelity, which contains DXM and bupropion (Wellbutrin), found that 6% of the people taking Auvelity experienced ED and other symptoms of sexual dysfunction, compared with none of the people taking a placebo.

DXM has other well-known side effects. It can lead to the following conditions that may also lead to ED:

A 2021 case study on a person who had an overdose on DXM suggests that major changes in your body’s ability to regulate hormones and neurotransmitters, such as serotonin, can cause conditions like serotonin syndrome that are known to cause side effects such as ED.

No evidence exists that links doxylamine directly to ED.

But similar first-generation antihistamines, such as diphenhydramine (Benadryl), are known to have side effects like ED. They can also cause drowsiness, dizziness, and painful urination.

Many other OTC and prescription medications are also likely to cause ED.

OTC drugs that cause erectile dysfunction

Nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil), have been linked to ED.

Many OTC antihistamines are also known to cause ED, including:

Prescription drugs that cause erectile dysfunction

Many commonly prescribed antidepressants are linked to ED, including:

Other prescription medications that have been linked to ED include:

Other side effects that can be caused by the active ingredients in NyQuil include:

Consider getting medical help if you’re suddenly having trouble getting or keeping an erection, especially after you begin taking NyQuil or another medication.

ED often goes away on its own, especially if it’s a side effect of a medication that you’re only taking for a short period.

But ED that doesn’t get better may be a sign of an underlying condition. Get medical care if you have ED along with any other new symptoms or side effects of a medication that don’t go away.

Here are some of the most frequently asked questions about ED and medications.

Can DayQuil cause erectile dysfunction?

DayQuil contains almost all of the same active ingredients as NyQuil except doxylamine. This means that it may have some of the same side effects.

Some types of DayQuil also contain active ingredients like phenylephrine and guaifenesin. Neither of these are linked to ED. Phenylephrine is sometimes injected into the penis to treat erections that don’t go away (priapism).

Do antihistamines cause erectile dysfunction?

Antihistamines, especially first-generation antihistamines like Benadryl and Dramamine, have been linked to ED.

Can antibiotics cause erectile dysfunction?

There’s no evidence that antibiotics can cause ED.

Get medical help if you begin to experience ED after starting NyQuil or if ED doesn’t go away after stopping NyQuil or other medications.