How Long Can You Take Cold Medicine Like Robitussin, Delsym, and Sudafed?
Key takeaways:
There are many cold medicines available over the counter (OTC). Each type of cold medicine may contain different ingredients that treat specific symptoms. Be sure to read the active ingredient list on the OTC label before taking it.
Cold medicines typically work quickly to relieve your symptoms. But you should only take them for a short period of time (often 7 days or less). Your primary care provider or pharmacist can help determine how long you should take OTC cold medicines.
If you take cold medicine for longer than recommended, your risk of unwanted side effects, such as high blood pressure, goes up. These risks vary, depending on which medications you’re taking.
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Table of contents
Cough and cold medicine can be useful to help relieve symptoms caused by the flu or common cold. Most of these remedies are available over the counter (OTC), making it easy to access products that provide quick relief.
OTC cold medicines are generally safe and effective for most people. But they come with their own set of risks if taken longer than recommended. But what are these risks? And how long can you take cold medicine?
What are the different types of cold medicines available?
There are many different types of OTC cold medicines available. It's important to carefully read the OTC medication label for the list of active ingredients. If you’re unsure about a product’s ingredients, your pharmacist is a great resource to answer any questions you have.
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Examples of common ingredients found in many OTC cold medicines include:
Expectorants: Guaifenesin (Mucinex)
Cough suppressants: Dextromethorphan (Delsym)
Antihistamines: Diphenhydramine (Benadryl), doxylamine (Unisom SleepTabs), and chlorpheniramine (Aller-chlor)
Pain relievers and fever reducers: Acetaminophen (Tylenol) and ibuprofen (Advil, Motrin)
Decongestants: Phenylephrine (Sudafed PE), pseudoephedrine (Sudafed), and oxymetazoline (Afrin)
Combination cold medicines contain two or more of these active ingredients. These products can eliminate the need to take multiple cold medications. While convenient, it’s crucial to be aware of what medications are included in them. It can be easy to accidentally take too much of certain ingredients.
Popular combination cold products include:
NyQuil (acetaminophen / dextromethorphan / doxylamine)
Mucinex DM (guaifenesin / dextromethorphan)
Tylenol Cold and Flu Severe (acetaminophen / phenylephrine / dextromethorphan / guaifenesin)
Good to know: Studies show that oral phenylephrine isn’t effective in relieving nasal congestion. While it’s not considered harmful for most people to take, there are more effective nasal decongestants available.
How long can you take cold medicine for?
It depends on the medication. There are different recommendations on how long you can take cold medicines based on their active ingredients. But, typically, you should only take them for a few days.
Below are some general guidelines on how long you should take certain cough and cold products. But keep in mind that your healthcare team may have different recommendations about when to stop taking cold medicine based on your health and medication history.
Expectorants and cough suppressants: Up to 7 days
Antihistamines: Up to 10 days for cold symptoms (can be taken long term for allergies)
Pain relievers / fever reducers: Up to 3 days for fever or 10 days for pain
Oral decongestants: Up to 7 days
Nasal decongestants: Up to 3 days
How long does a cold last? Here’s what to expect from the four stages of the common cold.
Vitamin C and colds: Many people swear by high doses of vitamin C when they start to get sick. But does it help?
Getting enough sleep: It’s not always easy to get a restful night’s sleep while you’re fighting a cold. Review these tips for getting good-quality rest when you’re sick.
The information listed above is specific to adults. Some cold medicines shouldn’t be given to children, especially those under the age of 4. So it’s best to discuss safe dosages of OTC cold medicine for your child with their pediatrician.
What happens if you take cold medicine for too long?
When you take cold medicines longer than recommended, your risk of experiencing side effects increases. And these effects depend on the active ingredients found in the medication you’re taking.
Expectorants and antihistamines
Generally speaking, long-term use of expectorants and antihistamines seems to be well tolerated by most people. But low risk doesn’t mean risk free. It’s a good idea to speak with your primary care provider if you feel like you need to take these longer than recommended on their OTC labels.
Cough suppressants
Cough suppressants, such as dextromethorphan, carry a risk of misuse and dependence. And, when people take large amounts, this OTC cough medicine can cause serious side effects, including raised heart rate, seizures, and loss of consciousness.
Acetaminophen
Acetaminophen has very few side effects when taken as directed. But it can contribute to liver damage if you take higher than recommended doses. This potentially life-threatening side effect can also happen if you’re taking lower doses every day long term.
Ibuprofen
Taking ibuprofen long term can raise your risk of severe side effects, some of which can be life threatening. These include stomach ulcers or bleeding, kidney damage, and heart attacks. And the higher the dose of ibuprofen you take, the greater your risk of these complications.
Decongestants
Oral decongestants, such as pseudoephedrine, can raise your blood pressure and heart rate. The longer you take them, the more likely you’ll experience these effects. And if you already have high blood pressure, your risk may be higher.
Decongestant nasal sprays can cause rebound (worsening) congestion when used for more than 3 days in a row. These nasal sprays are less likely to raise blood pressure or heart rate than oral decongestants. But it’s still a possible side effect for people who have existing blood pressure or heart problems.
Take our quiz: OTC cold and cough medicines
How long does it take for cold medicine to work?
Cold medicines generally work pretty quickly. Depending on the type of cold medicine, this time can vary. The table below provides a list of medications commonly included in cough and cold products, along with the typical time it takes for them to work.
Medication type | Common active ingredients | How long it takes to work |
|---|---|---|
Expectorant | Guaifenesin | |
Cough Suppressant | Dextromethorphan | |
Antihistamine | Diphenhydramine Doxylamine Chlorpheniramine | |
Pain reliever / fever reducer | Acetaminophen Ibuprofen | 20-45 minutes for acetaminophen 30-60 minutes for ibuprofen |
Decongestant | Phenylephrine Pseudoephedrine Oxymetazoline | 30 minutes for oral pills 5-10 minutes for nasal sprays |
Why is your cold medicine not working?
The reasons cold medicine doesn’t always work aren’t fully understood. But it’s important to keep in mind that OTC cold remedies don’t treat the cause of a cold — just the symptoms. That’s because the common cold is caused by viruses, and OTC medications aren’t effective against viruses. But some studies have shown that certain medications seem to provide more benefits than others in relieving your symptoms.
Research has found that both acetaminophen and ibuprofen work similarly well for pain in adults and children. But ibuprofen seems to work better for fever in children. Combining an antihistamine and a decongestant may provide some relief for a runny nose, sneezing, and congestion. Other OTC cold medicines weren’t found to provide significant relief for most people.
How long does a cold typically last?
Most people experience cold symptoms for about 7 to 10 days. Symptoms typically begin 1 to 3 days after being exposed to the cold virus. But it’s possible for some cold symptoms, such as a runny nose or cough, to last for up to 3 weeks.
Does taking cold medicine weaken your immune system?
There’s no good evidence that taking cold medicine weakens your immune system.
Currently, expert organizations, like the American Academy of Family Physicians and the CDC, don’t provide any sort of warning like this. They state that some OTC cold medicines may provide temporary relief. They also provide guidance on when to seek medical care.
When should you see a healthcare professional about your cold?
As noted above, the common cold lasts around 7 to 10 days. So call your primary care provider if you’re not feeling better after this time has passed. You should also reach out if you notice any of the following:
Your symptoms are severe
Your symptoms start improving and then get worse again
You have a fever lasting longer than 3 days
You have shortness of breath
You have chest pain or dizziness
You have blood in any mucus you’ve coughed up
The bottom line
There are many different types of over-the-counter (OTC) cold medicines available with different active ingredients. Each medication has specific recommendations on how long you should use them. But in general, you should only take cold medicine for a few days. Long-term use can lead to unwanted or potentially serious side effects, such as high blood pressure. It’s best to speak with your healthcare team about which cold medicine is best for you.
Why trust our experts?
References
Allan, G. M., et al. (2014). Prevention and treatment of the common cold: Making sense of the evidence. Canadian Medical Association Journal.
Centers for Disease Control and Prevention. (2024). Manage common cold.
DeGeorge, K. C., et al. (2019). Treatment of the common cold. American Family Physician.
MedlinePlus. (2022). Guaifenesin.
National Center for Biotechnology Information (2024). PubChem compound summary for CID 5360696, dextromethorphan.
U.S. Food and Drug Administration. (2023). FDA clarifies results of recent advisory committee meeting on oral phenylephrine.
