This is why you have such crazy dreams when you take Nyquil

Whenever you come down with a pesky cold or a case of the flu, you probably reach for a familiar bottle in your medicine cabinet when it comes time to try and sleep off your sickness. Yep, we’re talking about Vicks NyQuil — and honestly a lot of the brand’s sibling products.

Notoriously known as a knockout potion, NyQuil doses your body with acetaminophen (a pain reliever and fever reducer), dextromethorphan hydrobromide (a cough suppressant), and doxylamine succinate (a powerful antihistamine) as its active ingredients. Flu meds like NyQuil can impact sleep patterns and lead to vivid dreams. It can help relieve your most uncomfortable symptoms quickly and allow your body to get the rest it needs to restore its healthy status, but it can also give you some pretty wild dreams. Like, dancing with talking unicorns and falling to your doom in the center of a volcano, dreams.

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Why is that exactly for sleep?

Well, most experts blame it on the doxylamine succinate. Antihistamines are known for their drowsy side effects, helping you fall asleep and stay asleep, but they can also create some interesting interactions once you’ve drifted off to dreamland. It’s important to consult a doctor about these medication side effects, especially if they disrupt your sleep.

Antihistamines block the production of histamine, a certain kind of neurotransmitter, in your brain. (Makes sense, right?) It’s responsible for regulating your appetite, your body temperature, inflammation and — you guessed it — your sleep-wake cycle. And doxylamine specifically blocks the neurotransmitter acetylcholine, which triggers rapid eye movement (REM) sleep and, therefore, is in charge of your dream state. Understanding drug interactions is crucial, as they can significantly impact your sleep quality.

So what happens is your NyQuil dose puts off REM sleep longer than your normal sleep cycle typically does and then, as the medicine wears off, your brain experiences a rush of acetylcholine, creating a quick rebound of REM sleep in an attempt to make up for lost time. And its that quick shift that leads to all of your bizarre (and often terrifying) dreams. Having less melatonin due to certain medications can also lead to sleep issues like insomnia and nightmares.

It’s also worth noting that NyQuil isn’t the only company that uses doxylamine succinate in cold and flu medicines, so if you’re not ready to experience the wild adventures that your imagination has in store for you while on the mend, maybe read those ingredient labels and skip this bad boy. Various medications, including those for ADHD, high cholesterol, and diabetes, can influence sleep quality and dream states. The timing of taking these medications at night can further affect your sleep.

These medications can lead to nightmares as a side effect, impacting the quality of your sleep and overall well-being. Not everyone experiences these side effects, as individual responses to medications can vary.

Other medications, such as antidepressants, beta blockers, and even some antibiotics, can also lead to vivid dreams. Over the counter medications, like certain antihistamines, can cause unusual side effects, including vivid dreams or nightmares.

The disturbances in dreams are a common side effect of these medications. They can also impact your sleeping patterns, leading to issues like insomnia and vivid dreams.

Some over-the-counter cold and flu medications, particularly those containing antihistamines and dextromethorphan, can lead to trippy dreams or vivid nightmares due to their effects on REM sleep.

This article originally appeared on Swirled.