4 Cold Medications That Can Interact With Supplements

Supplements offer health benefits, but they may also interact with common cold medications in ways that increase side effects or reduce effectiveness.

1. Decongestants

Decongestants are one of the most common ingredients in cold and flu products because nasal congestion is a frequent and uncomfortable symptom of these conditions.

Pseudoephedrine and phenylephrine are decongestants commonly found in cold and flu medications. They work by constricting blood vessels in the nose to reduce swelling and congestion. They can also raise heart rate and blood pressure and may complicate underlying conditions like anxiety and insomnia.

The following supplements can worsen these effects:

• St. John's wort

• Caffeine

• Bitter orange

2. Antihistamines

Antihistamines are frequently included in multi-symptom cold and flu medications that target symptoms such as a runny nose, sneezing, and watery eyes.

Antihistamines like diphenhydramine (the active ingredient in Benadryl) and even non-drowsy formulas like loratadine can cause drowsiness in some people. When taken with certain supplements, these effects may be enhanced.

The following supplements should be avoided when taking medications that contain antihistamines:

• Goldenseal

• St. John's wort

3. Cough Suppressants

Antitussives (cough suppressants) like dextromethorphan are also often found in cough and cold medications. Some supplements can interact with this medication, increasing the risk of dangerous side effects.

St. John's wort poses the most evident risk due to the potential for serotonin syndrome. Serotonin syndrome is a drug reaction that causes too much serotonin (a chemical produced by nerve cells) in the body. While rare, it can be life-threatening.

4. Pain Relievers

Some cold medications include Tylenol (acetaminophen) or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen for pain and fever relief. Certain supplements can increase bleeding risk or irritate the stomach when combined with NSAIDs specifically.

Use these supplements with caution when taking cold and flu medications that contain NSAIDs:

• Fish oil

• Gingko biloba

• Garlic

Potential Risks of Interactions

Supplements have gained popularity because they offer a more natural alternative to traditional treatments. However, they can still contain active ingredients that interact with medications.

Potential risks of cold and flu medication interactions include:

• Increased sedation or drowsiness

• Increase in blood pressure or heart rate

• Impact on liver function

• Increased bleeding risk

• Reduced effect of the medication

Because many cold medications contain multiple active ingredients, the potential for interactions is higher than with other single-ingredient medications. Be sure to discuss any supplements or cough and cold medications you are taking with your healthcare provider on a routine basis.

Tips for Preventing Interactions

To prevent interactions, take the following precautions while using cold medicine and supplements:

• Thoroughly read the active ingredients list on both supplements and medications.

• Avoid formulations that treat multiple symptoms by only treating symptoms you are experiencing.

• Use supplements only when needed.

• Talk to a healthcare provider or pharmacist if you take multiple supplements or have chronic conditions.