What are the negative effects of cayenne pepper?

October 29, 2025 •

4 min read

While celebrated for its flavor and purported health benefits, excessive consumption of cayenne pepper can cause significant digestive upset, including gastritis and heartburn. Understanding what are the negative effects of cayenne pepper is crucial for anyone with sensitive digestion or pre-existing conditions.

Quick Summary

Excessive intake of cayenne pepper, primarily due to its capsaicin content, can cause gastrointestinal distress, burning sensations, and skin irritation. It may also interact with certain medications and pose risks for individuals with pre-existing health conditions or allergies.

Key Points

Capsaicin is the irritant: The active compound, capsaicin, gives cayenne pepper its heat but is also responsible for adverse effects like gastrointestinal and skin irritation.
Avoid excessive consumption: High doses of cayenne, often from supplements, are more likely to cause severe side effects such as stomach cramps, nausea, and diarrhea.
Beware of drug interactions: Cayenne can interfere with medications, especially blood thinners, ACE inhibitors, and certain asthma drugs, by altering absorption or increasing risk of bleeding.
Handle with care: Topical contact with fresh or powdered cayenne can cause significant burning and irritation to the skin and eyes; always wash hands thoroughly or wear gloves.
Consult a doctor: Individuals with digestive disorders (ulcers, IBS), pregnant women, and those on specific medications should seek professional medical advice before increasing cayenne intake.
Severe reactions are possible: In rare instances, excessive capsaicin has been linked to severe cardiovascular events like coronary vasospasm and allergic reactions.

The active component in cayenne pepper, capsaicin, is responsible for both its fiery heat and many of its reported health effects. However, this same compound is also the source of the spice's negative side effects when consumed in large quantities or applied topically. While many people can enjoy cayenne in moderation without issue, others may be more sensitive and experience adverse reactions. The severity often depends on an individual's tolerance, the amount consumed, and whether it is in whole, powdered, or supplement form.

Gastrointestinal Discomfort

One of the most widely reported negative effects of cayenne pepper is its impact on the digestive system. The capsaicin can irritate the mucosal lining of the stomach and intestines, particularly in those with pre-existing gastrointestinal conditions.

Stomach Pain and Cramps: High doses can cause acute gastritis, leading to sharp abdominal pain, cramps, and general stomach irritation.
Heartburn and Acid Reflux: Capsaicin can either trigger or worsen heartburn in some individuals, while in others it may have a protective effect. The effect seems to depend on the person's unique physiology and sensitivity.
Nausea, Vomiting, and Diarrhea: Consuming excessive amounts can overstimulate the digestive system, resulting in nausea, vomiting, and diarrhea as the body attempts to expel the irritant.

Topical and Mucous Membrane Irritation

Handling fresh cayenne peppers or concentrated capsaicin products can lead to irritation upon contact with the skin and mucous membranes. The burning sensation is a result of capsaicin activating pain-sensitive nerves.

Skin Irritation: Direct contact can cause a painful burning sensation, redness, and itching. It is crucial to wear gloves when handling fresh peppers and to avoid touching the face, eyes, and other sensitive areas.
Eye Irritation: Rubbing the eyes after handling cayenne can cause intense burning, watering, and redness. This painful but temporary effect can be soothed by flushing with milk or water.
Respiratory and Nasal Issues: Inhaling powdered cayenne can lead to respiratory tract irritation, sneezing, and coughing.

Potential Drug Interactions

Cayenne pepper and capsaicin supplements can interfere with certain medications, altering their effectiveness or increasing the risk of side effects. It is vital to consult a healthcare provider before using cayenne if you are on any of the following types of medication:

Blood-Thinning Medications: Capsaicin has mild blood-thinning properties and can increase the risk of bleeding when taken with anticoagulants like warfarin, aspirin, or ibuprofen.
ACE Inhibitors: For patients with hypertension, cayenne may interfere with the action of ACE inhibitors, and in rare cases, high doses may cause blood pressure spikes.
Asthma Medications (Theophylline): Capsaicin can increase the body's absorption of theophylline, a bronchodilator used to treat asthma, which can lead to increased side effects.

Rare and Severe Side Effects

While uncommon, certain individuals may experience more serious reactions to cayenne pepper, particularly with high-dose supplements.

Allergic Reactions: Although rare, a true allergy to cayenne can result in hives, swelling, or difficulty breathing, which requires immediate medical attention.
Cardiovascular Events: In extremely rare cases, excessive intake of cayenne supplements has been linked to coronary vasospasm and myocardial infarction in otherwise healthy individuals.

Comparison of Cayenne Intake Effects

To better illustrate the difference between typical culinary use and excessive or concentrated intake, the following table compares their potential outcomes.


Feature	Moderate Culinary Use (Seasoning)	High-Dose Supplementation (Capsules)
Gastrointestinal Impact	Mild, if any; aids digestion for many	Higher risk of severe stomach pain, gastritis, and diarrhea
Topical Interaction	Minimal risk, unless handling fresh peppers	Potential for skin and eye irritation from contact with concentrated form
Drug Interaction	Unlikely to cause issues with small amounts	Increased risk of interfering with blood thinners, ACE inhibitors, and asthma meds
Allergic Reactions	Very rare; typically mild if it occurs	Low risk, but can be severe in sensitive individuals
Cardiovascular Risk	Minimal to none	Extremely rare but possible risk of heart-related events with misuse
Overall Safety	Generally safe for most people	Should be used with caution and medical supervision, especially for pre-existing conditions

Conclusion

While cayenne pepper offers numerous benefits when consumed in moderation, understanding the negative effects of cayenne pepper is critical for safe consumption. For most people, a sensible approach—using it as a culinary spice rather than a high-dose supplement—will prevent adverse effects. Individuals with pre-existing conditions like ulcers, GERD, or IBS, those taking certain medications, and pregnant or breastfeeding women should exercise extra caution and consult a healthcare provider. By being mindful of dosage and listening to your body's response, you can enjoy the flavor of cayenne while avoiding its potential downsides. To learn more about herbal interactions with medication, visit Memorial Sloan Kettering Cancer Center.

Frequently Asked Questions

Excessive consumption of cayenne pepper can irritate the stomach lining and potentially lead to gastritis, which could worsen pre-existing ulcers. Individuals with ulcers or other stomach conditions are generally advised to avoid or limit consumption.

While some research suggests cayenne may help lower blood pressure over time, in rare cases high doses can cause a short-term increase. It can also interfere with medications for hypertension, like ACE inhibitors.

If you get cayenne pepper in your eyes, rinse the area with milk or water to soothe the burning sensation caused by the capsaicin. The irritation should subside eventually, but it can be intensely uncomfortable.

While culinary amounts are generally safe, pregnant women should consult their doctor before taking cayenne supplements, as the spice can worsen heartburn and there is insufficient research on high-dose safety.

Yes, cayenne pepper has mild blood-thinning properties and can increase the risk of bleeding when taken with anticoagulant medications like warfarin or aspirin. It is important to discuss this with a healthcare provider.

There is no specific recommended daily amount, as tolerance varies. Generally, a small amount as a spice is fine, but consuming excessive amounts—especially in concentrated supplement form—can cause digestive upset.

If you have a sensitive stomach, the capsaicin in cayenne pepper can irritate the lining of your esophagus and stomach, leading to a burning sensation, pain, or heartburn.