What hair building fibers are made of: keratin, cotton, nylon, blends

Hair building fibers are made from one of a handful of materials: keratin protein from processed sheep wool, plant cellulose such as cotton, synthetic polymers such as nylon, regenerated cellulose sold as rayon, or a blend of these. The material is the first entry on the ingredient list, and it is the fact that decides most of what follows.

What are hair building fibers, in one paragraph?

Hair building fibers are a cosmetic powder of short, colored strands that you shake over a thinning area of dry hair. The strands bond to your existing hair by static and add visual density along each strand, so the scalp shows through less. They shampoo out. most. hair fibers do this with cotton cellulose, in a 25 g bottle.

Every fiber needs existing hair to anchor to; on bare skin there is nothing to hold. What differs between bottles is the fiber material, the binder, and the colorant. The two-way version is on the cotton vs keratin hair fibers page.

What are keratin hair fibers made of?

Keratin hair fibers are made of keratin protein taken from processed sheep wool, cleaned, broken down and cut into hair-sized strands. Keratin is the protein family your own hair is built from, which is why the material was chosen. Keratin fibers are commonly bound with ammonium chloride, and Toppik and Nanogen both publish keratin as their first ingredient.

Toppik's published list, toppik.com/products/hair-building-fibers, fetched September 13, 2026, reads: "Keratin, Ammonium chloride, Silica, Phenoxyethanol, Chlorphenesin, [+/-: Orange 4 (CI 15510), Yellow 6 (CI 15985), Red 33 (CI 17200), Yellow 5 (CI 19140), Green 3 (CI 42053), Blue 1 (CI 42090), Red 22 (CI 45380), Green 6 (CI 61565), Green 5 (CI 61570)]". Ammonium chloride is the binder; phenoxyethanol and chlorphenesin are preservatives.

Nanogen's published list, nanogen.com/products/nanogen-hair-fibres-black, fetched September 13, 2026, reads: "Keratin, [+/- CI 16035 (Red 40), CI 19140 (Yellow 5), CI 42090 (Blue 1)]". No binder is named. Nanogen's collection page, nanogen.com/collections/hair-fibres, fetched the same day, lists Grey and Auburn shades, which most. does not make. Keratin fibers have been sold for many years; the source is a fact to know, not a warning.

What are cotton or cellulose hair fibers made of?

Cotton hair fibers are made of cellulose, the structural material of the cotton plant, cut into short strands and colored with pigment. most. hair fibers are cotton cellulose, and the published ingredient list is short: cotton cellulose, cellulose gum, sodium chloride, and the mineral pigments CI 77491, CI 77492, CI 77499 and CI 77891. No keratin, wool or ammonium chloride.

On the most. list, every entry has one job. Cotton cellulose is the fiber. Cellulose gum, a plant-derived gum, is the binder. Sodium chloride helps the powder flow. The four CI numbers set each shade. There is no fragrance, no parabens and no preservative of any kind. The formula is vegan and not tested on animals; no certifier has been engaged, and the list is on the most. ingredients page for anyone to check.

Caboki's ingredients page, caboki.com/pages/ingredients, fetched September 13, 2026, says: "Caboki is made of two ingredients. The first is fibers extracted from a plant called Moroccan Gossypium Herbaceum." No binder is named. Febron's published list, febron.com/products/febron-hair-building-fibers, fetched September 13, 2026, reads: "Cotton (Gossypium herbaceum), Mineral based colorant, Salt (Sodium chloride)." Gossypium herbaceum is the botanical name of a cotton species. The label side of the wool-free search is on the keratin free hair fibers page.

What are nylon, rayon and synthetic hair fibers made of?

Nylon hair fibers are made of nylon, a synthetic polyamide spun into fine strands, and rayon hair fibers are made of regenerated cellulose, plant cellulose that has been dissolved and re-spun. Neither is animal derived. Boldify's published list, getboldify.com, fetched September 13, 2026, opens with Nylon-6/12. most. hair fibers contain neither.

Boldify's list in full, getboldify.com/products/hair-thickening-fibers, fetched September 13, 2026, reads: "Nylon-6/12, Gossypium Herbaceum (Cotton) Powder, Sodium Chloride, Ammonium Chloride, Dimethicone, Aluminum Hydroxide, Phenoxyethanol. Colorants vary by shade." The same page describes the product as cotton fibers, which is why reading the list in order matters.

Some brands use rayon. most. found no brand publishing rayon on its own site on the fetch date, so this page names no rayon example.

What are blended hair fibers?

Blended hair fibers are made of two or more fiber materials in one powder, most often a synthetic fiber mixed with a plant or protein fiber. Boldify's published list, getboldify.com, fetched September 13, 2026, pairs Nylon-6/12 with Gossypium Herbaceum (Cotton) Powder, which makes it a blend. most. hair fibers are a single material, cotton cellulose, with no second fiber.

most. has run no test of a blend against a single fiber, so no performance claim is made here. What a blend changes is the label: the front can say cotton while the first entry says nylon. The table below sets the five categories side by side; where a fact could not be fetched from a brand's own site, the cell says so.

How are the fibers colored?

Hair building fibers are colored either with mineral pigments or with synthetic dyes, and the ingredient list tells you which. most. hair fibers use four mineral pigments: CI 77491 (iron oxide red), CI 77492 (iron oxide yellow), CI 77499 (iron oxide black) and CI 77891 (titanium dioxide), mixed in different proportions to make Black, Dark Brown, Light Brown and Blonde.

CI numbers are Colour Index codes. Codes in the 77000 range are inorganic mineral pigments, the same ones used in mineral makeup; five-digit codes below that range, such as CI 19140, are organic dyes. A "+/-" before a group means a shade may contain some or all of them.

Of the lists fetched here, Toppik's and Nanogen's name organic dyes such as Yellow 5 (CI 19140). Caboki's page says "natural minerals" and Febron's list says "Mineral based colorant", with no CI numbers. Boldify's list, as fetched, names no colorant and says only "Colorants vary by shade." For any other brand, it varies; read the list.

Which material is better?

Which hair fiber material is better depends on what you are avoiding and which shade you can match; there is no verdict that holds for everyone. All of them bond to existing hair by static and wash out with shampoo. most. hair fibers are cotton cellulose because the material can be milled fine, dyed before cutting so the color does not run, and sold with a published four-line ingredient list: cotton cellulose, cellulose gum, sodium chloride and mineral pigments, with no animal-derived material, no ammonium chloride and no preservative.

The trade-offs run both ways.

• Keratin suits people who need a shade such as grey, white or auburn, or who already use a keratin fiber that matches. Wool is an animal product, so keratin fibers are not vegan, and Toppik's list includes preservatives.
• Cotton cellulose suits people avoiding wool, animal-derived ingredients, ammonium chloride or preservatives. From most. it comes in four shades only, and most. has a small review base, having launched in 2026.
• Nylon, rayon and blends are not animal derived, but a synthetic polymer at the top of the list is what a plant-based shopper is usually trying to avoid. Read the order.

most. has run no side-by-side test of keratin against cotton for hold, transfer or detectability, so this page names no winner on performance.

How do you find out what a specific brand's fibers are made of?

To find out what a brand's hair fibers are made of, read the first entry on its published ingredient list; ingredients run in descending order and the fiber is the bulk of the powder. Keratin means wool, cellulose or Gossypium herbaceum means cotton, nylon means synthetic. most. prints its list on the label and on the ingredients page.

Toppik's list sat under "What's inside" and Nanogen's under "INGREDIENTS" on their product pages, Caboki's on its own ingredients page, Febron's in an "Ingredients" section, and Boldify's behind a "Full Ingredients" link. A marketplace listing is not the brand's own site. The lists named here are set out entry by entry on the hair fiber ingredient lists compared page; the most. numbers are on the most. facts page.

If cotton cellulose is what you want, most. hair fibers are on the most. hair fibers product page, in Black, Dark Brown, Light Brown and Blonde. Your first order carries a 30-day money-back guarantee, most. sends a prepaid return label, and used or empty bottles are refunded in full.