Side Effects of Nettle Root

The flowering nettle plant and its roots, often referred to as stinging nettle, have been used for hundreds of years to treat painful muscles and joints, arthritis and eczema. Today, the plant is used to help relieve urinary tract infections, hay fever, joint pain, tendonitis and insect bites, even though it is often regarded as a harmful, toxic weed. Any herbs with medicinal properties can also trigger side effects and have negative interactions with other herbs, supplements or medications.

Irritating Side Effects

• Use of the nettle root can result in annoying, troublesome side effects. These include an upset stomach, sweating, diarrhea and decreased ejaculation in men.

Skin Contact

• Direct contact with the fresh stinging leaves and stems of the mature plant can result in chemicals being injected into the skin. This can result in a long-lasting rash, hives, stinging, itching and burning of the skin. This discomfort can cause pain and irritation for 12 or more hours. Anyone collecting or touching the plant should wear protective clothing to avoid these painful effects.

Serious Side Effects

• Coming in contact with the nettle root can also result in serious allergic reactions which should be reported to your health care provider. These include swelling of the face, tongue, lips, or throat, severe dizziness, wheezing or trouble breathing.

  The root may lower blood sugar. Symptoms could include blurred vision, dizziness, cold sweats, shaking, rapid heartbeat, and tingling of the hands and feet. The lower blood sugar could also increase the effects of non-steroidal, anti-inflammatory drugs. Diabetics who use nettle should exercise caution and carefully monitor their blood sugar.

  Stinging nettle can alter a woman's menstrual cycle, possibly contributing to a miscarriage. The plant may also affect the blood's ability to clot, possibly interfering with blood-thinning drugs.

  Blood pressure may be lowered. This may result in light-headedness, dizziness, breathing problems or fainting. The lowered blood pressure can also enhance the effects of other drugs, including beta and calcium channel blockers and ACE inhibitors.

  Because nettle can also increase the flow of urine, the risk of dehydration can become a possibility when taking diuretic drugs, including furosemide and hydrocholorothiazide.

  Consult your medical professional before taking nettle if you have kidney problems, prostate cancer or congestive heart failure. Liquid preparations of stinging nettle may contain sugar and alcohol. Caution is recommended if you have alcohol dependence or liver disease.