Horsetail (Equisetum arvense)

Dried aerial parts of Equisetum arvense, Horsetail, the silica-rich primitive plant that has remained essentially unchanged for over 300 million years. Horsetail is a living fossil - Equisetum-like plants were dominant during the Carboniferous period, when giant Equisetum relatives grew over 100 feet tall and became the source of much of the world's coal. The modern small Equisetum species are direct descendants of these ancient plants.

Key Facts

Botanical name

Equisetum arvense

Family

Equisetaceae (the only living family in its order)

Common names

Horsetail, Shavegrass, Scouring Rush, Bottlebrush

Living fossil

Equisetum lineage essentially unchanged for 300+ million years

Distinctive content

Unusually high silica content (5-7% by dry weight)

Traditional uses

Bone/connective tissue, hair/nail support, scouring (historical), kidney support

What is Horsetail?

Horsetail is among the most ancient lineages of land plants still living. The plant is unusual for its exceptionally high silica content - the silica gives the stems a slightly abrasive texture, leading to historical use as "scouring rush" for cleaning pots and pans. Traditional Western and TCM herbalism uses horsetail primarily as a silica-providing herb for bone, connective tissue, hair, and nail support.

How to Use Horsetail

Tea: steep 1-2 teaspoons in 8 oz hot water for 10 minutes; strain through fine cloth. Long infusion: 1/4 cup in a quart of hot water, steep 4-8 hours, strain - better silica extraction. Tincture: alcohol partially extracts the silica compounds.

Safety Information

Horsetail contains thiaminase, an enzyme that breaks down vitamin B1 (thiamine). Long-term high-dose use is not recommended. Choose herbal-grade preparations (which are typically processed to reduce thiaminase). Avoid in individuals with thiamine deficiency, alcoholism, or eating disorders. Not recommended during pregnancy.

Frequently Asked Questions

What is horsetail used for?
Traditional silica-providing herb for bone, connective tissue, hair, and nail support.

What makes horsetail unusual?
Exceptionally high silica content (5-7% by dry weight) and an unchanged lineage for 300+ million years.

Why is it called "scouring rush"?
The silica content gives the stems a slightly abrasive texture; historical use was for cleaning pots and pans.

Is horsetail safe long-term?
Long-term high-dose use is not recommended due to thiaminase content (which breaks down vitamin B1).

Was horsetail really 100 feet tall in the past?
Yes; giant Equisetum relatives during the Carboniferous period reached over 100 feet and contributed to coal deposits.

Is horsetail safe during pregnancy?
No; not recommended during pregnancy.

This product has not been approved by the Food and Drug Administration and is not intended to diagnose, treat, cure, or prevent any disease. We recommend that you consult with a qualified healthcare practitioner before using any herbal products, particularly if you are pregnant, nursing, or on any medications.