How can you take care of your hair if you don't even know what stage of life it's in? Your hair is not frozen in time. It lives, evolves and reacts. What you find on your brush, your pillow or even the tiles in your shower? It's all the result of a precise biological cycle, all too often ignored. At any given moment, every strand of hair on your scalp is growing, pausing, falling out or in transition to one of these states.

Understanding the hair growth cycle means you can stop doing your hair care blindly and start focusing on what really works.

The four phases of the hair growth cycle

Anagène: where it all begins

This is where it all comes together. The anagen phase is when your hair is actively growing - rooted, nourished, alive. It lasts from two to seven years. The longer it lasts, the more your efforts can really bear fruit.

On average, 85 % of the hair on your scalp is in the anagen phase, i.e. your body is functioning normally - meaning that it is well nourished, that the hair on your scalp is in the anagen phase, and that the hair on your scalp is in the anagen phase. your hormones are stable and that your scalp is not subjected to any chronic stress or inflammation.

The duration of this phase is not the same for everyone. There are many factors to consider: genetics, hormones, ethnic origin, diet - all influence how long your hair remains in the growth phase, before moving on to the next stage.

Let's take a concrete example: an iron deficiency. It can be enough to slow growth, weaken your roots, or even listen to the anagen phase of your hair cycle. Correct it through your diet and appropriate supplementation. You'll see your follicle start to do its job again. No need for a miracle. Just give it the little push it needs.

And what about effective care? They don't just coat your fiber. They target the follicle. With active ingredients such as caffeine, ginseng, niacinamide and peptides, the anagen phase of your cycle is prolonged.

Catagen: the silent exit

No alert. No signal. Just a transition that no one notices, except maybe you, in front of that fallen hair you weren't expecting.

The catagen phase lasts just two to three weeks. It's short, but decisive. This is the moment when your hair gradually detaches itself from its source of nutrition - your scalp - and stops growing. It doesn't die yet. It just goes dormant. Around 1% of your hair goes through this stage at any one time. It's not much, but every passage counts: the follicle shrinks, activity slows down, and your scalp puts itself to rest.

You may not be aware that this phase exists. And yet, it's often the one that causes you to panic. You lose a handful of hair and suddenly wonder if your routine has stopped working. Spoiler: no. It's not a failure - it's not your fault. These hairs have just completed their cycle. Nothing more, nothing less.

Telogen: the rest, not the end

Often mistaken for a fall, the telogen phase is actually a pause. A voluntary stop in the cycle. Your hair stops growing, but it doesn't fall out yet. It just sits there. Waiting. Until the signal arrives.

Around 10 to 15 % of your hair is permanently in the telogen phase. But this figure can increase dramatically when your body feels at risk. Extreme fatigue, post-partum, post-Covid, or post-breakup. This is called telogen effluvium: a protective reaction. Your body cuts off everything that isn't essential. Even your hair.

So no, it's not your turn to cut things short.

The answer? Gentle skin care. Massages with jojoba oil. No miracle cures or obsessive research. Just regularity, a little space and a little peace.

Exogenous: letting go

If telogen is the pause, exogen is the exit. Hair finally falls out. Between 50 and 150 a day is normal. No, you're not going bald. No, it's not because of your shampoo. Your scalp is simply turning over a new leaf.

Do you hesitate to brush your hair for fear of losing even more? In fact, the opposite is true. Brushing helps free hair that has already fallen out, not pull it out.

The real problem is when hair loss exceeds its quota. When you lose significant handfuls of hair and your hair density visibly changes. At that point, it's no longer exogenous, and you can panic. More seriously: if your hair loss becomes massive, prolonged and visible. This is no longer normal, as you've just come out of a regular hair growth cycle.

What disrupts the hair cycle?

Internal factors

When the body suffers, so does the hair.

Hormonal imbalances - from thyroid disorders to PCOS - can short-circuit the cycle, shortening the anagen phase and tipping more hair into the telogen phase. Nutritional deficiencies such as iron, protein or zinc do the same. What about stress? It's not a metaphor. Chronic cortisol peaks are directly linked to premature hair loss.

External factors

External aggressors are just as merciless.

Chemical straightening, daily straightening or bleaching put follicles under stress. Pollution, UV rays, even that sulfate-filled "detox" shampoo - each of them weakens the scalp's resilience.

We often blame genetics, but it's our habits that cause the damage.

Cycle-related fall disorders

• Androgenetic alopecia shortens the anagen and miniaturizes the follicles. It's progressive. Subtle at first. But treatable if you act fast.
• Telogen effluvium This does not permanently alter the follicle, but triggers a fall after a physical or emotional shock.
• Alopecia areata the most unpredictable, completely blocking the cycle in certain areas - caused by autoimmune drift.

Each condition speaks a different biological language. The secret is knowing which one applies to you.

How to support a healthy hair cycle

Nutrition and healthy living

You can't compensate for a nutritional deficiency with a mask.

Fill your plate with biotin-rich eggs, omega-3s from flaxseed or salmon, and iron from green vegetables or lentils. Get a good night's sleep. Drink enough fluids. Manage stress by building routines adapted to your lifestyle. In the event of deficiencies, take food supplements, always under medical supervision.

Scalp care rituals

Gentle weekly exfoliation frees follicular pathways. Peptides and caffeine serums awaken dormant follicles. Avoid aggressive brushes - a boar bristle brush or your fingers will do. Consistency is more powerful than complexity.

Professional interventions

Science offers tools - but none of them is universal.

Microneedling with PRP can revive stubborn follicles. Light therapy (LLLT) is ideal for the early stages of hair loss. But there's no substitute for a proper diagnosis. When in doubt, consult a certified trichologist or dermatologist - not a TikTok tutorial.

Our final take away

Your hair cycle is a biological mechanism, structured and vastly underestimated. This four-phase rhythm explains your periods of density, fall and stagnation. Above all, it determines whether or not your treatments are effective. Being aware of this cycle is to stop improvising. It means understanding why your hair falls out. When it grows back and how to act.