Can I Take Sudafed and DayQuil Together?

Doubling up on cold medications like Sudafed and DayQuil isn’t usually recommended. 

While these and other over-the-counter (OTC) products may look different, they often contain the same or similar active ingredients. Taking too much of any ingredient, or taking ingredients you don’t need, won’t help you feel better faster. But it does increase your risk of side effects.

Is Taking More Than One Cold Medication Risky?

It can be. “The biggest risk of mixing OTC cold medications is unintentionally doubling up on the same, or similar, active ingredients,” agrees Joshua Khalili, M.D., an internal medicine physician at the UCLA Health Extensivist Program located in Santa Monica. Another risk is ingesting ingredients you don’t actually need.

This can happen because many cold and flu medications are combination products. That means they contain two or more active ingredients.

With Sudafed and DayQuil, the main concern is overlapping ingredients. Some DayQuil formulas include a decongestant, and Sudafed itself is a decongestant, so taking them together can lead to an unintentional double dose.

Why More Isn’t Always Better

Taking too much of a single medication can increase your risk of side effects. For example, many combination products contain the pain reliever acetaminophen (Tylenol). Taking more than one product with acetaminophen can push you past the safe maximum daily dose of 4,000 milligrams per day for adults (or less for certain groups of people). This increases the risk of liver injury. 

Avoid doubling up on decongestants as well, says Angelique Nguyen, PharmD, a medication therapy management pharmacist at Johns Hopkins Care at Home in Baltimore, Maryland. Many cough and cold products include one of two decongestants: phenylephrine or pseudoephedrine. 

Taking too much of these medications can overstimulate your nervous system and cause anxiety or trouble sleeping. Decongestants can also increase your blood pressure and heart rate. So you may need to be extra careful, and potentially avoid them altogether, if you have high blood pressure, heart disease, or heart rhythm problems, says Dr. Khalili.

Like many cold and flu products, DayQuil and Sudafed are umbrella brand names for multiple products with similar names but different active ingredients. For example, some Sudafed products, like Sudafed Sinus Congestion, have pseudoephedrine only. Others, like Sudafed PE Head Congestion + Pain Relief, contain entirely different medications: phenylephrine and ibuprofen (Advil). That’s why reading the label, not just the brand name on the box, is so important.

What’s in Your Cold Medication (And Why It Matters)

Common ingredients in cold and flu medications include:

• Pain relievers relieve pain, aches, and fever. Examples include acetaminophen and ibuprofen (Advil, Motrin).
• Decongestants help with nasal stuffiness. Examples include pseudoephedrine and phenylephrine. Though oral phenylephrine isn’t considered effective for nasal congestion, it’s still in several OTC products.
• Cough medications help relieve a cough. Examples include the cough suppressant dextromethorphan (Robitussin) and cough expectorant guaifenesin (Mucinex). 
• Antihistamines can dry up a runny nose and may help you sleep. Examples include diphenhydramine (Benadryl) and doxylamine (Unisom). Before taking an antihistamine, talk to a healthcare professional. For many people, they’re not always the safest option.

Many cold and flu medications may contain two or more of these ingredients. This helps to treat different symptoms at once, which is convenient in some cases. But it also makes it easy to take medications you don’t actually need, or to double up on ingredients without realizing it.

Cold Medications in Kids

Cold medications are riskier for children, especially combination products. Young children are more sensitive to side effects, and certain ingredients should be avoided entirely, including decongestants. While we have limited research on decongestant use in children, the small amount we do have hasn’t found them very effective. So the risk of side effects outweighs the benefits.

Accidental overdosing with products containing acetaminophen is also a risk. If you’re considering medication for your child, talk to a pharmacist or pediatrician first. They can help you choose a safe, symptom-specific option at the correct dose. They may also be able to recommend non-medication options.

Is It Ever OK to Take Cold Medications Together?

Yes, sometimes taking cold medications together can help. But make sure to ask yourself the questions below first:

• Am I treating only the symptoms I’m experiencing? A good rule of thumb is to take the fewest medications necessary to treat your symptoms, says Dr. Khalili. For example, if you have a headache and nasal congestion, you may benefit from a pain reliever and a decongestant. But other ingredients, like cough suppressants, may not be necessary. 
• Am I getting the same ingredient from multiple products? Getting the same ingredient from different products isn’t usually recommended. It increases your risk of side effects and makes it difficult to stay below the safe, maximum daily dose.
• Should I talk to a healthcare professional first? It’s a good idea if you’re choosing a cold medication for a child, have multiple chronic conditions, take several medications, or drink alcohol regularly. A pharmacist or other healthcare provider can help you pick a safer option.

Knowing How and When To Take Cold Medications

Taking your cold medications correctly and knowing how long to use them is important. Some ingredients are meant for short-term use only. For example, oral decongestants usually shouldn’t be taken for more than seven days in a row, says Dr. Nguyen. If you think you need them for longer, it’s best to talk to a healthcare provider first.

Timing your doses is also important. Decongestants taken too late in the day can cause restlessness, anxiety, and trouble sleeping. For that reason, it’s best to avoid pseudoephedrine and phenylephrine in the late afternoon or evening. Instead, consider other congestion-relief options that won’t interfere with sleep, such as using saline nasal sprays or a humidifier.

How to Know What’s in an OTC Medication: Reading the Label

Knowing how to read a medication label is a helpful skill. This is especially true for cold and flu products, where popular brand names like DayQuil cover a wide range of products with different ingredients. Here’s how to read a label quickly and effectively:

1. Look at the back or side of the medication box. The most important information isn’t on the front, it’s on the back or side. This is called a “Drug Facts” label, and it’s required on all OTC medications.
2. Look for the term “active ingredients.” This section lists each medication in the product and what symptoms it treats.
3. Read the recommended dose and maximum daily amount. This is especially important for ingredients like acetaminophen, which is in many cold and flu products.

Anytime you’re thinking about taking a new medication, check all your medication labels again. See if you are accidentally doubling up on medications. If you’re not sure, talk to your pharmacist and ask them to help you, says Dr. Nguyen. 

If you think you’ve taken too much of any one ingredient, call your healthcare provider immediately or call Poison Control at 1-800-222-1222, even if you don’t have symptoms. If you experience potentially severe symptoms like a racing or pounding heart, chest pain, or severe anxiety or panic attacks, seek urgent medical care, says Dr. Khalili. Dizziness that doesn’t go away, fainting, or severe headaches are also reasons to seek care right away.

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