What it is

Horsetail extract is derived from the sterile aerial stems of Equisetum arvense, a perennial plant belonging to one of the oldest botanical lineages still in existence. Often referred to as a “living fossil,” horsetail has been used traditionally in European and Asian herbal medicine for supporting urinary health, connective tissue integrity, and mineral balance.

The extract is characterized by its relatively high content of silica (in the form of soluble silicic acid), flavonoids (such as quercetin and kaempferol derivatives), and phenolic compounds, all of which contribute to its biological activity. The silica content, in particular, has driven modern interest in horsetail as a supplement for hair, skin, nails, and bone health [1].

How it works in the body

Horsetail’s primary mechanism of action is linked to its silica content, which plays a structural role in connective tissues. Silica is involved in the synthesis and stabilization of collagen and glycosaminoglycans, key components of skin, cartilage, bone, and other connective tissues. By supporting collagen formation, horsetail extract may contribute to the maintenance of tissue strength, elasticity, and overall structural integrity [2].

In addition to its structural role, horsetail contains flavonoids and phenolic antioxidants, which may help modulate oxidative stress and support cellular health. These compounds can influence inflammatory pathways and may contribute to the plant’s traditional use in conditions involving tissue repair or irritation.

Horsetail also exhibits mild diuretic properties, which are thought to arise from a combination of its mineral composition and phytochemical profile. Clinical and experimental studies suggest that horsetail extract can modestly increase urine output without significantly disturbing electrolyte balance, supporting its use in urinary tract health and fluid regulation [3]. This effect may help explain its traditional application in promoting urinary clearance and reducing mild fluid retention.

Emerging research has also explored horsetail’s potential role in bone metabolism, with some studies suggesting that silica-rich extracts may support bone mineralization processes, although human evidence remains limited and further research is needed.

Primary benefits

• Supports connective tissue structure through silica-related mechanisms
• Contributes to hair, skin, and nail strength and integrity
• May support bone health as part of a broader mineral framework
• Provides mild diuretic effects that may support urinary function
 • Offers antioxidant support through flavonoid content

Typical supplemental range

Common doses range from 300–500 mg of standardized extract per day, depending on the formulation and intended use.

Safety notes

Horsetail extract is generally considered safe when used in purified, standardized forms and within recommended doses. Raw or unprocessed horsetail may contain thiaminase, an enzyme that can degrade vitamin B1, which is why properly prepared extracts are preferred. Long-term or excessive use is not recommended without professional guidance.

Did you know?

Horsetail belongs to one of the oldest plant lineages on Earth—its prehistoric relatives grew as large, tree-like plants over 300 million years ago.

References

1. Sandhu NS et al. Equisetum arvense: pharmacological and phytochemical profile. J Pharm Pharmacogn Res. 2010.
   

2. Cetojevic-Simin DD et al. Antioxidative and antiproliferative effects of horsetail extracts. Afr J Tradit Complement Altern Med. 2010.

3. Carneiro DM et al. Evaluation of the diuretic effect of Equisetum arvense in humans. Evid Based Complement Alternat Med. 2014.