Health Guide


What is it?

Horsetail is an herb used to treat a urine infection (in-FECK-shun), edema (swelling), and an enlarged prostate gland in men. It may also be used to heal wounds and to treat hair, skin, nail, teeth, or bone problems. Horsetail may be added to skin care products and to anti-aging lotions. It may be used to treat enuresis (en-u-RE-sis) (bed wetting) in children and incontinence (in-KON-ti-nens) (loss of urine) in adults.

Other names for Horsetail include: Bottle brush, Equisetum, Giant horsetail, and Mexican horsetail.

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic (uh-LER-jik) to any medicine (prescription or over-the-counter (OTC) or dietary supplement)
  • are pregnant or plan to become pregnant while using this medicine
  • are breast feeding
  • have other health problems, such as high blood pressure or heart or blood vessel disease


Talk with your caregiver about how much Horsetail you should take. The amount depends on the strength of the medicine and the reason you are taking it. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.

Side Effects:

Stop taking your medicine right away and talk to your doctor if you have any of the following side effects. Your medicine may be causing these symptoms which may mean you are allergic to it.

  • Breathing problems or tightness in your throat or chest
  • Chest pain
  • Skin hives, rash, or itchy or swollen skin

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • Heart beat changes (in animals) (1)
  • Muscle weakness, walking problems, cold limbs, and fever (in animals) (1)
  • Skin infection (1,2,3)


1. Anon: Horsetail. In: DerMarderosian A (ed): The Lawrence Review of Natural Products. Facts and Comparisons, St. Louis, MO; 1991.

2.Jellin JM, Gregory P, Batz F et al: Pharmacist's Letter/Prescriber's Letter Natural Medicines Comprehensive Database, 3rd ed. Therapeutic Research Faculty, Stockton, CA; 2000.

3. Sudan BJ: Seborrhoeic dermatitis induced by nicotine of horsetails Equisetum arvense L. Contact Dermatitis 1985; 13(3):201-202.

4. Brinker F: Herb Contraindications and Drug Interactions, 2nd ed. Eclectic Medical Publications, Sandy, OR; 1998.

5. Perez Gutierrez RM, Laguna GY & Walkowski A: Diuretic activity of Mexican equisetum. J Ethnopharmacol 1985; 14(2-3):269-272.

6. McGuffin M, Hobbs C, Upton R et al (eds): American Herbal Products Association's Botanical Safety Handbook. CRC Press, Boca Raton, FL; 1997.

7. Henderson JA, Evans EV & McIntosh RA: The antithiamine action of Equisetum. J Am Vet Med Assoc 1952; 120:375-378.

Last Updated: 7/4/2018
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.

All rights reserved