Side Effects of the Ilex Herb

Ilex, or Ilex paraguayensis, is also called yerba mate. It's a South American native plant that has been used for centuries to increase energy, reduce feelings of depression and increase urination. When it is used in traditional ways, Ilex is a natural substance that generally causes no adverse side effects. However, it is included in herbal supplements designed for dieting, and some products containing this herb have impurities or additives that can be harmful.

Who Should Not Take Ilex

If you suffer from liver disease, diabetes or high blood pressure, or if you are pregnant or nursing, be cautious about using Ilex. Ilex is included in some liquid formulas, which can contain alcohol or sugar, or both. Always talk to your doctor or other qualified medical professional before you take any herb, and always do your homework to learn what properties it contains and the possible side effects and contraindications that have been cited.

Nausea and Vomiting

Ilex affects some individuals by causing stomach upset, which can result in nausea and vomiting. Stomach pain is another possible side effect.

Irritability and Nervousness

When you drink an excessive amount of Ilex, you can experience the same kinds of side effects that too much coffee can cause. If you feel irritable or nervous after drinking a preparation containing Ilex, stop taking it and speak with your doctor.

Increased Urination

Because Ilex is a diuretic, increased urination is a common side effect. Flushing your urinary system can be a good thing---if and when you want that to happen---but if you experience a significant increase in urination you might become dehydrated. Use caution and monitor your urination amount and frequency if you choose to drink Ilex tea or take other products that contain it.

Serious Side Effects

A little nervousness or a small increase in your urination are not serious conditions, but it has been reported that Ilex can sometimes cause your eyes to turn yellow and your urine to turn a dark color, indicating a problem with your liver. If fever or an irregular heartbeat occurs, seek immediate medical attention.

Not FDA-Approved

The U.S. Food and Drug Administration has not reviewed Ilex in any form for its effectiveness or safety. It is known, however, that certain prescription medications can have an adverse reaction when taken along with Ilex. Examples of some drugs that you should not take with Ilex include any type of diuretics or water pills, quinolone antibiotics, stimulants, appetite suppressants and cough and cold formulas that contain stimulants. Do not drink coffee, tea or caffeinated sodas when taking Ilex.

Keywords: Ilex paraguayensis, yerba mate, stimulant herbs

About this Author

Barbara Fahs lives on Hawaii island, where she has created Hiā€˜iaka's Healing Herb Garden. Barbara wrote "Super Simple Guide to Creating Hawaiian Gardens," and has been a professional writer since 1984. She contributes to Big Island Weekly, Ke Ola magazine, and She earned her B.A. at UCSB and her M.A. from San Jose State University.