Hair loss and brittle nails: understanding the hair cycle

BIOLOGYST · Cellular beauty & glow

Hair loss and brittle nails: understanding the hair cycle

Hair and nails: what science really says, and how to act from within.

You find it in your brush, in the shower, on your pillow. Your nails break at the slightest strain. You feel your hair is getting thinner, that the volume has gone. These signs are often dismissed, and yet they say something about the state of your inner biology.

Hair loss and brittle nails are almost never a surface problem. They are signals that your hair follicles and nail matrices are lacking something essential: sulphur amino acids, structural minerals, enzymatic cofactors. These are parameters that can be identified, ideally with a healthcare professional.

I. Your hair is alive, and it follows a precise cycle

The hair cycle in 3 phases

Every hair goes through three successive phases, in an unchanging order:

When the cycle goes off track: excessive hair loss

Hair loss is considered excessive when more than 100 to 150 hairs fall out a day on a persistent basis, when density visibly decreases, or when the anagen phase shortens and hair grows back finer and shorter than before.

There are several types of hair loss, but the most common in women are:

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II. Keratin: what is your hair really made of?

Keratin makes up 95% of your hair

Keratin is a fibrous protein that forms most of the structure of hair and nails. It is not a single molecule but a network of intertwined proteins, held together by very strong chemical bonds, notably disulphide bridges, bonds between sulphur atoms.

This is precisely why the sulphur amino acids, cysteine and methionine, play a central role in hair biology. Without them, the body cannot make strong keratin. And without strong keratin, the hair fibre is fragile, brittle and fluffy.

Why oral keratin has been reassessed

For a long time, experts thought that keratin taken orally was simply broken down into amino acids in the gut, with no particular benefit for hair. Recent research has considerably nuanced this view.

The key is the hydrolysed form: when keratin is broken down into small peptides (hydrolysed keratin), the available research describes fragments that partly survive digestion, pass into the bloodstream and are distributed to keratin-rich tissues: hair follicles, nail matrix, skin. The authors report that they provide not only sulphur amino acids, but also biosynthesis signals described as stimulating keratinocytes.

“Hair is built from within. Topical keratin stays on the surface: the oral route is the one research is exploring to reach the root.”

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III. The micronutrients that make the difference

Zinc: the conductor of hair growth

Zinc is the most studied trace element in hair loss. It is involved in more than 300 enzymatic reactions, several of which directly concern folliculogenesis (formation of the hair follicle) and keratinisation. Zinc contributes to the maintenance of normal hair and normal nails.

Mechanistically, the literature describes zinc as involved in regulating 5α-reductase, the enzyme that converts testosterone into DHT, the molecule associated with follicle miniaturisation in androgenetic alopecia. It is also a cofactor of superoxide dismutase (SOD) and contributes to the protection of cells from oxidative stress.

Iron: fuel for the follicles

The hair follicle is one of the fastest-dividing tissues in the body: it therefore needs large amounts of oxygen, carried by iron via haemoglobin. Iron deficiency, even mild (low ferritin without anaemia), is described in the literature as able to shorten the anagen phase and to be accompanied by diffuse hair loss.

Published data describe it as the most common deficiency in women of childbearing age and as the leading nutritional cause of female hair loss. Iron contributes to the reduction of tiredness and fatigue, to normal oxygen transport in the body and to normal cognitive function.

Silicon: the forgotten beauty mineral

Silicon is little known to the general public, but it contributes to the structure of the extracellular matrix that surrounds and supports the hair follicle. It is part of collagen and elastin fibres, and the available research describes a role in the mechanical strength of the hair fibre and the nail plate, as well as in keratinocyte moisture retention.

Bamboo extract is the most concentrated plant source of bioavailable silicon: up to 70% of its dry matter is silicon dioxide.

Selenium: the antioxidant guardian of the follicle

Selenium is the essential cofactor of glutathione peroxidase: the antioxidant enzyme that protects hair follicle cells against oxidative damage. Without selenium, the follicle is particularly vulnerable to the oxidative stress generated by inflammation, pollution and UV radiation. Selenium contributes to the maintenance of normal hair and normal nails and to the protection of cells from oxidative stress.

A selenium shortfall is associated with a decline in hair quality: a finer, more fragile fibre that breaks more easily, as well as changes in pigmentation.

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IV. Hair & Nail Regenesis: the formula dedicated to your hair and nails

Hair & Nail Regenesis is the BIOLOGYST formula designed for hair and nails. It combines the most scientifically documented ingredients, at studied doses, and covers every link in the chain studied by research: keratin structure, supply of sulphur amino acids, minerals and vitamins.

Cynatine® HNS · 500 mg: patented hydrolysed keratin

The most documented hydrolysed keratin. Cynatine® HNS is a highly bioavailable hydrolysed keratin, derived from cold-processed New Zealand sheep's wool (Keratec process). According to the supplier's research, its peptide structure allows it to partly survive digestion, be absorbed into the bloodstream and be distributed to the hair follicles and nail matrix. It provides sulphur amino acids involved in keratin synthesis (notably cysteine, serine, glutamic acid); the authors describe a stimulation of keratinocyte activity.

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L-Cysteine · 200 mg

Direct precursor of keratin's disulphide bridges. L-cysteine is the most abundant sulphur amino acid in hair keratin: it accounts for around 14% of the amino acid composition of hair. It is involved in forming the disulphide bridges that give hair its mechanical strength. It is also the direct precursor of glutathione, a molecule that cells produce themselves and that research describes as central to their defence system.

L-Methionine · 50 mg

An essential sulphur amino acid that the body cannot make. Methionine is an essential amino acid: the body cannot produce it, so it must come from food or supplementation. It is the precursor of cysteine via the methylation cycle. It is also involved in the synthesis of creatine and carnitine, and in DNA methylation in follicle cells. The available research links a methionine shortfall to slower keratinisation.

Bamboo extract · 150 mg (of which silicon: 112 mg)

Strengthening the structural matrix of the follicle and the nail. Bamboo extract standardised in organic silicon is the most concentrated plant source of bioavailable silicon. Silicon is involved in the synthesis of the collagen and elastin fibres that form the architecture of the hair follicle and the nail plate. The available studies describe an improvement in the mechanical strength and elasticity of hair, as well as a reduction in the fibre porosity that encourages breakage.

Zinc + Selenium + Iron · Zinc: 10 mg (100% NRV) · Selenium: 50 µg · Iron: 7 mg

A mineral trio for hair growth and protection. Zinc: contributes to the maintenance of normal hair and normal nails; it regulates 5α-reductase, takes part in keratinocyte proliferation and contributes to the protection of cells from oxidative stress via SOD. Selenium: a cofactor of glutathione peroxidase, it contributes to the maintenance of normal hair and normal nails and to the protection of cells from oxidative stress. Iron: essential for oxygen supply to the bulb and for the length of the anagen phase; it contributes to the reduction of tiredness and fatigue. Its deficiency is the number one nutritional cause of female hair loss.

Vitamin E + B vitamins and vitamin A · Vit. E: 14.4 mg (120% NRV)

Antioxidant protection and support for follicle metabolism. Vitamin E contributes to the protection of cells from oxidative stress, notably the lipid membranes of follicle cells exposed to peroxidation. Vitamins B5, B6 and B9 contribute to the reduction of tiredness and fatigue, and vitamins B5 and B6 contribute to normal energy-yielding metabolism; they also take part in the cellular metabolism of the follicle and in melanin production.

Discover Hair & Nail Regenesis

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In summary

Hair loss and brittle nails are almost never inevitable. They are signals that your hair follicle lacks raw materials: hydrolysed keratin, sulphur amino acids, zinc, iron, silicon. Shortfalls that are often invisible in a standard blood test, but very real.

Hair & Nail Regenesis works on the whole chain: Cynatine® HNS provides hydrolysed keratin, L-cysteine and L-methionine supply the sulphur building blocks, bamboo supports the structure, and zinc, selenium and iron support the growth and protection of the follicle. All documented by scientific studies.

A three-month course: the length of a complete hair cycle.

Frequently asked questions

How many hairs do we normally lose a day?

Losing 50 to 100 hairs a day is normal: it is the natural turnover of the hair cycle. Hair loss is considered excessive above 100 to 150 hairs a day on a persistent basis, or when hair visibly grows back finer and shorter than before.

Does oral keratin really reach the hair?

In hydrolysed form, yes: small peptides partly survive digestion, pass into the circulation and are redistributed to keratin-rich tissues. The Glynis study (2012, n=50, 90 days) reports a 33% reduction in hair loss and tensile strength 47% higher than in the comparison group.

What is the leading nutritional cause of hair loss in women?

Iron deficiency. Rushton's study (2002) of 194 women with diffuse hair loss shows that 72% of them had low ferritin (below 40 ng/mL) despite normal haemoglobin. Iron contributes to the reduction of tiredness and fatigue and determines the oxygen supply to the bulb.

How long does it take to see a change?

The hair cycle spans 3 to 6 months: a course of at least 3 months is recommended, at 3 capsules a day with a meal. Results vary from person to person.

Which ingredients does Hair & Nail Regenesis contain?

Cynatine® HNS 500 mg (patented hydrolysed keratin), L-cysteine 200 mg, L-methionine 50 mg, bamboo extract 150 mg (including 112 mg of silicon), zinc 10 mg, selenium 50 µg, iron 7 mg, vitamin E 14.4 mg and vitamins A, B1, B2, B3, B5, B6 and B9. More ingredient analyses are available in the Active Ingredients blog and in the BIOLOGYST Journal.