Field Horsetail: the plant-based silica that gives skin its firmness

It has never bloomed. Long before the first flowers, field horsetail (Equisetum arvense) had already established itself in moist soils with a single building material: silica. Its ribbed stems are so laden with it that they creak when rubbed. In cosmetics, only an aqueous extract applied to the skin is used, chosen for its astringent feel and the clean finish it leaves on irregular skin texture.

Equisetaceae are the last heirs of a lineage that populated the Carboniferous swamps, more than 150 million years before the first flowering plants. No flowers, therefore, no fruit or seeds: reproduction occurs through spores, borne in spring by fertile brown, chlorophyll-free stems, which wither in a few weeks. Then come the green sterile stems of summer, whorled, ribbed, bristly - these are the ones harvested. The foliage is reduced to scales fused into a collar around each node. Hence the vernacular names: horsetail, rat-tail.

In the field, the recognition period is short. Fertile stems emerge from March to May; the green sterile stems then take over and grow 20 to 60 cm tall, hollow, articulated, so neatly interlocking that they can be dismantled node by node like a toy. It is at this stage, and only at this stage, that cosmetic harvesting makes sense.

Underground, a perennial rhizome sometimes runs more than a meter deep: this is what makes the species almost indestructible and feared in the garden. The genus includes about twenty species. Three are regularly encountered: field horsetail (Equisetum arvense), the most common and the only one used in cosmetics; winter horsetail (Equisetum hyemale), sold as Japanese horsetail for its persistent foliage and graphic habit, an ornamental planting species mostly seen in ponds; and great horsetail (Equisetum telmateia), spectacular at the water's edge, which has no other use than decorative.

What distinguishes these plants from all others is their cell wall. They deposit silica there, in amorphous and hydrated form - an organization confirmed by structural analysis conducted by G. Holzhüter, K. Narayanan, and T. Gerber and published in Analytical and Bioanalytical Chemistry in 2003. This mineralization explains the characteristic rustling of the stem and, historically, the use of dried horsetail as a mild abrasive to polish pewter and wood. No other perennial plant in our regions demonstrates this as extensively: it is from this singularity, and not from supposed properties, that the cosmetic interest of the species comes.

Ingredient (INCI name)	Part used	What the skin feels	Routine step	Target skin
Field Horsetail Equisetum Arvense Extract	Green sterile stems, harvested from June to August	Dry and astringent feel, slight surface tension effect	Water-based step: lotion or serum, before cream	Mature, devitalized, combination
Bamboo Bambusa Vulgaris Extract	Solidified exudate from stem nodes (tabashir)	Powdery, mattifying finish, very covering texture	Mask or scrub, once a week	Combination to oily, shiny T-zone
Seaweed Laminaria Digitata Extract	Thallus (entire frond), harvested at sea	Supple and moist film, immediate bouncy sensation	Mask or night cream	Dehydrated, dull, wind-exposed
Prickly Pear Opuntia Ficus-Indica Seed Oil	Cold-pressed seeds — commonly cited ratio: one ton of fruit for one liter	Dry oil, fast absorption, no sticky film	Last layer, at night, 2 drops	Dry, mature, tight

It is found in fields, embankments, landfills, and along railway lines, on heavy, clayey, water-retentive soil. Its presence is actually read as an indication: compacted, poorly drained land. It tolerates partial shade as well as full sun, which explains its omnipresence. In ornamental planting, Japanese horsetail is grown exclusively in pots or behind a rhizome barrier: planted directly in the ground, it colonizes the flowerbed in two seasons and cannot be dislodged. This flaw also makes its decorative career — evergreen foliage, green all year round, and a graphic design of vertical stems that contemporary gardens appreciate.

The harvest period is from June to August, on sterile green stems, cut a few centimeters from the ground in dry weather. Drying is done in the shade and flat, never in direct sunlight, until the weight stabilizes: the plant loses most of its water and retains little more than a fifth of its fresh weight. It is this dry matter that then goes into decoction or aqueous extraction, then filtration, before entering the formulation of cosmetic products.

A confusion needs to be clarified: horsetail manure, obtained by maceration or long decoction, is for garden use. It is sprayed diluted on the foliage of vegetable plants, in traditional garden use. It has nothing to do with facial care, and is never intended to be applied to the skin.

Why is silica always mentioned in relation to it?

Because the plant deposits it in the cell walls, in amorphous and hydrated form — this is what was shown by the structural analysis published by Holzhüter, Narayanan and Gerber in 2003. This plant silica is what makes the stem rough to the touch, and what led to its ancient use as a polishing abrasive.

Which skin types benefit from this extract?

Mature or devitalized skin looking for a firmer appearance, and combination skin whose texture is uneven in the T-zone. Use 3 to 4 drops morning and evening. For very dry or reactive skin, reduce to one application in the evening and always combine with a fatty substance.

Horsetail or bamboo: which one to choose?

Both provide silica, but at different points in the routine. Horsetail extract is aqueous: it is applied as a first layer, daily. Bamboo comes in powdered form, in a mask or scrub, typically once a week. The comparison table above details the four profiles.

Can I make a homemade decoction to apply to my face?

We advise against it. An unpreserved plant decoction becomes contaminated within 24 to 48 hours at room temperature, and its concentration remains unpredictable from one harvest to another. A cosmetic extract is dosed, filtered, preserved, and tested. As for horsetail manure, it is a garden preparation intended for plant foliage: it has no place in a bathroom.

How long does it take to see results?

The clean finish effect is visible within a minute of application. For everything else, wait 28 days and compare two photos taken under the same conditions, on day 0 and day 28. This is the only honest way to distinguish a real change from a good night's sleep.

What about nails and hair?

The same aqueous extract is found in hair formulas, for the feel it leaves on the fiber after rinsing. This fact sheet, however, only covers cosmetic use applied to the skin of the face: this is the only area we commit to.

Holzhüter G., Narayanan K., Gerber T., « Structure of silica in Equisetum arvense », Analytical and Bioanalytical Chemistry, vol. 376, 2003 · European Commission, CosIng inventory, entry « Equisetum Arvense Extract » (INCI name and declared cosmetic functions).