Background

Guava is a tree that grows in Central and South America. The fruit is commonly eaten fresh or made into beverages, jams, and other foods. Various parts of the plant, including the leaf and the fruit, are used as medicine.

People use guava leaf for stomach and intestinal conditions, pain, diabetes, and wound healing. The fruit is used for high blood pressure. But there is no good scientific evidence to support any uses of guava.

Safety Safety definitions

When taken by mouth: Guava fruit is LIKELY SAFE when eaten as a food. Guava fruit and guava leaf extract are POSSIBLY SAFE when used as a medicine, short-term. Guava leaf extract might cause temporary nausea or stomach pain in some people.

When applied to the skin: Guava leaf extract is POSSIBLY SAFE when applied to the skin or inside the mouth as a rinse. It might cause skin irritation in some people.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Guava is LIKELY SAFE when eaten as food. There isn't enough reliable information to know if guava is safe to use as medicine when pregnant or breast-feeding. Stay on the safe side and stick with food amounts until more is known.

Eczema: Guava leaf extract might make eczema worse. Guava leaf extract contains chemicals that can cause skin irritation, especially in people with skin conditions like eczema. If you have eczema, use guava leaf extract with caution.

Diabetes: Guava might lower blood sugar. If you have diabetes and use guava, check your blood sugar carefully.

Surgery: Guava might lower blood sugar. In theory, guava might increase the risk for bleeding or interfere with blood sugar control during and after surgical procedures. Stop using guava as a medicine at least 2 weeks before a scheduled surgery.

Effectiveness

Dosing & administration

The appropriate dose of guava depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for guava. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Interactions with pharmaceuticals

Medications for diabetes (Antidiabetes drugs)

Interaction Rating=Moderate Be cautious with this combination.

Guava might lower blood sugar. Diabetes medications are also used to lower blood sugar. Taking guava along with diabetes medications might cause your blood sugar to go too low. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.
Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.

Interactions with herbs & supplements

Herbs and supplements that might lower blood sugar: Guava might lower blood sugar. Using it with other herbs and supplements that have this same effect might increase the risk of low blood sugar in some people. Some of these products include devil's claw, fenugreek, guar gum, Panax ginseng, Siberian ginseng, and others.

Interactions with foods

There are no known interactions with foods.

Action

The guava FRUIT is a source of vitamin C, fiber, and other substances that act like antioxidants. Antioxidants slow down or stop the harmful effects of oxidation. Oxidation is a chemical reaction in which oxygen is added to a chemical element or compound. Guava LEAVES also contain chemicals with antioxidant and other effects. It is not known how guava works for medical conditions.