Decoding the Risks: What is the side effect of ginger and garlic in the body?

October 6, 2025 •

5 min read

A 2025 review of studies on popular spices found that while ginger and garlic offer health benefits in moderate amounts, excessive intake can lead to adverse effects. Understanding precisely what is the side effect of ginger and garlic in the body is crucial, especially for those with existing health conditions or taking specific medications.

Quick Summary

Consuming excessive ginger and garlic, particularly concentrated forms, can trigger digestive issues like heartburn and bloating, increase bleeding tendencies, cause breath and body odor, and lead to serious interactions with certain medications. Topical application can also cause skin irritation.

Key Points

Digestive Upset: Excessive consumption of ginger and garlic, especially raw, can cause heartburn, gas, bloating, and diarrhea due to compounds like allicin and fructans.
Increased Bleeding Risk: Both spices have antiplatelet effects and can increase the risk of bleeding, particularly when combined with blood-thinning medications or before surgery.
Drug Interactions: Consuming large amounts of ginger and garlic can interact with blood thinners, diabetes medication, and blood pressure medication, potentially causing dangerous fluctuations.
Allergies and Irritation: Allergic reactions can occur, with symptoms ranging from skin rashes and mouth irritation to severe anaphylaxis. Raw, topical application can cause chemical burns.
Special Populations Need Caution: Pregnant women, breastfeeding mothers, individuals with bleeding disorders, and those with certain heart conditions or gallstones should consult a doctor before increasing intake.
Amount Consumed is Key: Side effects are most common with large amounts, typically from concentrated forms, rather than the moderate amounts used in daily cooking.

Ginger and garlic are staples in global cuisine and traditional medicine, praised for their anti-inflammatory, antioxidant, and immune-boosting properties. However, their powerful bioactive compounds, like gingerol in ginger and allicin in garlic, are also responsible for potential side effects when consumed in large quantities or by sensitive individuals.

Common Digestive Side Effects

One of the most frequently reported adverse effects of both ginger and garlic is gastrointestinal distress, which can range from mild discomfort to more significant issues. The intensity and type of symptoms can vary based on the amount consumed, whether the spices are raw or cooked, and individual sensitivity.

Gastrointestinal Irritation from Garlic

Garlic, especially in its raw form, can irritate the stomach lining and digestive tract. This is partly due to allicin, the compound that gives garlic its pungent odor and many of its health benefits. For sensitive individuals, consuming raw garlic can lead to a burning sensation. Garlic also contains fructans, a type of carbohydrate that can ferment in the gut, causing gas and bloating in people with Irritable Bowel Syndrome (IBS) or fructan intolerance.

Ginger and Digestive Upset

Though often used to soothe nausea, consuming too much ginger can have the opposite effect. High intake can increase stomach acid production, which exacerbates symptoms like heartburn and acid reflux. It can also speed up the movement of food through the intestines, potentially causing diarrhea or bloating.

Increased Bleeding Risk

Both ginger and garlic possess antiplatelet properties, meaning they can inhibit blood clotting. While this can be beneficial for cardiovascular health, it poses a significant risk for those with bleeding disorders or individuals preparing for surgery.

Garlic and Blood Thinners: Concentrated garlic, in particular, may increase the effects of anticoagulant medications, leading to a higher risk of bruising and bleeding. Healthcare professionals often advise patients to stop taking garlic at least two weeks before surgery.
Ginger and Bleeding: Similar to garlic, consuming high amounts of ginger can prolong bleeding time and inhibit platelet aggregation. This effect is especially pronounced when ginger and garlic are combined.

Drug and Supplement Interactions

The antiplatelet and blood sugar-modulating properties of these herbs can lead to dangerous interactions with several common medications. It is essential to consult a doctor before increasing intake if you are on any of the following medications.


Medication Type	Ginger Interactions	Garlic Interactions
Anticoagulants/Blood Thinners	May increase bleeding risk with certain medications.	Can increase the risk of bleeding when taken with certain medications.
Diabetes Medications	Can potentially lower blood sugar levels, potentially affecting the action of antidiabetic drugs.	May affect the action of antidiabetic drugs, potentially leading to lower blood glucose.
High Blood Pressure Meds	Can potentially affect blood pressure levels, particularly when combined with certain medications.	May affect blood pressure-lowering effects of antihypertensive medications.
HIV/AIDS Medications	Some reports suggest potential interference with certain medications.	Can potentially interfere with the absorption of certain HIV medications.
Immune Suppressants	Immune-boosting properties may counteract drugs that suppress the immune system.	Can boost immune function, potentially interfering with immunosuppressants.

Potential Allergic Reactions

Although rare, some people can have an allergic reaction to ginger or garlic, a sensitivity that may extend to other members of the Allium family, such as onions or leeks. Symptoms can manifest in various ways:

Skin and Mouth Irritation: Raw garlic and ginger can cause a burning or tingling sensation in the mouth. When applied topically, raw preparations can lead to severe skin irritation, rashes, blisters, or chemical burns.
Systemic Symptoms: More severe allergic responses can include hives, swelling of the face or tongue, nasal congestion, difficulty breathing, or even life-threatening anaphylaxis.

Effects on Blood Pressure and Sugar

While studies show that both ginger and garlic can help regulate blood pressure and blood sugar, especially in patients with hypertension or diabetes, this can be problematic in specific situations. Individuals with naturally low blood pressure or those whose levels are already controlled by medication risk causing their blood pressure to drop too low, which can result in dizziness or fainting. Similarly, the hypoglycemic effect can be too strong for diabetics on medication, leading to dangerously low blood sugar levels if not monitored properly.

Special Population Precautions

Beyond general consumption, certain individuals and situations require special attention to avoid adverse effects:

Pregnant and Breastfeeding Women: While ginger is often used for morning sickness, excessive amounts are discouraged, and use should always be discussed with a doctor. Large amounts might carry a risk, though evidence is mixed. Garlic in large amounts is not considered safe during pregnancy or breastfeeding.
People with Gallbladder Disease: Ginger can increase bile production, which could potentially cause complications for individuals with gallstones.
Surgery Patients: Due to their blood-thinning properties, both ginger and garlic intake should be stopped at least two weeks before any scheduled surgery.

Other Considerations

Amount Consumed: Most negative side effects are associated with consuming large amounts, often through concentrated forms. The amounts typically used in cooking are generally safe for most people.
Unpleasant Odor: Garlic's sulfur compounds are famously responsible for bad breath and body odor, which can be absorbed into the bloodstream and released through pores.

Conclusion

While ginger and garlic offer a multitude of health benefits and are safe for most people in culinary amounts, understanding what is the side effect of ginger and garlic in the body is key to preventing health issues. From digestive distress to increased bleeding risk and medication interactions, the negative effects are predominantly associated with excessive consumption, particularly through concentrated forms. Moderation is a universal rule, and for specific populations—including pregnant women, those with bleeding disorders, or people on medication for blood pressure or diabetes—a consultation with a healthcare professional before increasing intake is strongly recommended. For more comprehensive information on dietary supplements, consult authoritative sources like the National Center for Complementary and Integrative Health (NCCIH) at nih.gov.

Important Safety Measures for Ginger and Garlic Consumption

Consult Your Doctor: Before increasing your intake of ginger or garlic, discuss your medical history, current medications, and health goals with a healthcare professional.
Monitor Your Health: Keep a close eye on your blood pressure or blood sugar levels, especially when making significant changes to your intake, to avoid adverse effects.
Consider the Amount: Consuming large amounts in concentrated form are most likely to cause side effects. Stick to moderate, culinary amounts unless otherwise advised.
Avoid Raw Application: Never apply raw ginger or garlic to the skin, as it can cause severe irritation and burns.
Plan Ahead for Surgery: Inform your surgical team about all herbal supplements you are taking and stop consuming ginger and garlic at least two weeks before any procedure.
Recognize Allergies: Be aware of symptoms like rashes, swelling, or breathing issues. If you suspect an allergy, stop consumption immediately and seek medical attention.
Consider Cooking: Cooking garlic can reduce some of its potency and potential for causing gastrointestinal upset compared to consuming it raw.

Frequently Asked Questions

Yes, consuming large quantities of raw ginger and garlic together can amplify their effects. For example, their combined antiplatelet properties could increase the risk of bleeding more significantly than either ingredient alone. Digestive upset is also more likely with raw, high-dose consumption.

Cooking can alter the chemical composition of ginger and garlic. For garlic, cooking at high temperatures can inactivate the enzyme alliinase, which produces allicin, potentially reducing its effect on stomach irritation and blood thinning. For ginger, high-heat processing may also slightly modify its compounds, though culinary use generally poses less risk than concentrated forms.

People with bleeding disorders, those taking anticoagulant medications, individuals with GERD or IBS, pregnant and breastfeeding women, and those with scheduled surgeries should be cautious. People with naturally low blood pressure or low blood sugar should also monitor their intake.

No, bad breath is a common but not the only side effect. Other issues include digestive upset (gas, bloating, heartburn), body odor, and increased bleeding risk with large amounts. Severe allergic reactions are also possible, though rare.

While the amount can vary based on individual factors and form of consumption, high doses increase the risk of side effects. It is generally recommended to stick to moderate amounts, such as those typically used in cooking.

While uncommon, allergies to ginger and garlic can occur. Symptoms can include skin reactions (hives, itching), digestive problems, and respiratory issues. In severe cases, it can lead to anaphylaxis. Those with allergies to other Allium species (like onions) may also have a garlic sensitivity.

Yes, applying raw, crushed garlic or ginger to the skin can cause severe irritation, rashes, blisters, and even chemical burns. This is due to the potent compounds within the plants. It is generally advised against for topical use.