Horsetail (Equisetum arvense) is a traditional herb used for centuries, often claimed to promote hair health and growth. This belief stems from its distinctive mineral profile. The potential benefits of horsetail are not due to rapid new growth, but rather its capacity to strengthen existing hair structures, an effect linked to its high concentration of a specific mineral.
Silicon: The Key Mechanism for Hair Health
Horsetail is one of the richest natural sources of elemental silicon, which exists as silica in the plant. This mineral forms orthosilicic acid (OSA), a highly bioavailable form the human body can readily absorb. Silicon acts as a cross-linking agent in the formation of connective tissues.
This action supports the synthesis of collagen, which provides scaffolding for the scalp and hair follicle. By supporting the hair shaft’s integrity, silicon helps bond protein molecules within the strand. This creates a more resilient hair fiber, reducing breakage and improving texture and luster. Silicon’s influence on the cuticle contributes to a smoother surface that reflects light more effectively.
Clinical Trials and Research Findings
Research into horsetail’s effects focuses on supplementing with its rich silicon content. One randomized, placebo-controlled study involving women with thinning hair found that a supplement containing horsetail extract reduced hair shedding. Participants also experienced a significant increase in hair thickness after approximately 90 days of consistent use.
Further investigations have examined choline-stabilized orthosilicic acid, a form of silicon abundant in horsetail. This research observed improvements in hair and nail brittleness, suggesting a strengthening effect on keratin-based structures. The existing body of evidence is not extensive, and many studies combine horsetail with other ingredients. Scientific findings support the herb’s ability to reinforce existing hair and reduce loss from breakage.
Safe Usage and Preparation Methods
Horsetail is consumed in standardized extracts, dried teas, or applied topically. Standardized capsule supplements are common, ensuring a consistent silica percentage, usually 10% to 15%. Common dosage recommendations for dry extract supplements range from 600 to 1,110 milligrams daily, taken orally.
For a traditional approach, an herbal infusion can be prepared by steeping one to two grams of the dried aerial parts in boiling water for ten to fifteen minutes. This tea can be consumed up to three times a day for short periods. Topical applications, such as a hair rinse, use a stronger decoction poured over the hair after shampooing to strengthen the hair shaft.
Important Safety Considerations
Horsetail use is safe when taken appropriately and for short durations, but active compounds require caution. Horsetail has a natural diuretic property, increasing urination and potentially leading to a loss of minerals like potassium. Individuals taking prescription diuretics should be mindful, as combining them could lead to dangerously low potassium levels (hypokalemia).
The plant contains the enzyme thiaminase, which breaks down thiamine (Vitamin B1). While commercial preparations usually eliminate this enzyme, prolonged consumption of raw or improperly prepared horsetail can cause thiamine deficiency. The herb is not recommended for pregnant or breastfeeding women, or individuals with pre-existing kidney or heart conditions. Horsetail may interact with medications such as lithium and those for diabetes, so consulting a healthcare provider before starting a regimen is necessary.