At first, it was just a few hairs on your pillow. Later, you started finding them in the shower, on your brush, or even on your clothes.

And then the inevitable question arises: is this still normal?

What you probably don't know is that the hair you see falling out today may have begun its path toward shedding weeks or even months ago.

Each follicle goes through its own cycle of growth, transition, rest, and shedding. While some of your hairs are actively growing, others have stopped, and some are about to fall out.

To understand what might be happening with your hair, there are four words you need to know: anagen, catagen, telogen, and exogen.

Your hair does not grow all the time

Although we cannot see it, underneath the skin, the hair follicle is constantly changing.

The hair cycle was traditionally described by three main phases: anagen, catagen, and telogen. Currently, exogen is also recognized to specifically describe the shedding of the hair shaft.

The most important thing is that all your follicles do not go through these stages at the same time. This lack of synchronization allows us to normally retain hair while a small proportion sheds each day.

But what happens in each phase?

Anagen phase: this is where your hair really grows

The anagen phase is the period of active growth.

During this period, the cells in the follicle matrix divide rapidly and produce the hair shaft. On the scalp, this stage can last for approximately 2 to 6 years, although its duration depends on individual and genetic factors.

Under normal conditions, about 80–90% of the follicles on the scalp are in this phase.

Why can some people have much longer hair?

The duration of the anagen phase is one of the reasons.

A person whose hair remains in active growth for longer can reach a greater length before that follicle transitions to the next stage.

Therefore, hair growth depends not only on how much it grows each month, but also on how long it remains growing.

Catagen phase: growth begins to stop

After years of growth, the follicle enters a much shorter transition.

The catagen phase usually lasts about 2 to 3 weeks. During this period, the proliferative activity of the matrix ceases, and the lower part of the follicle begins a controlled regression process.

The hair stops growing actively.

But it does not necessarily fall out yet.

Only a small proportion of follicles are in this phase at any given time.

Telogen phase: the hair goes into rest

Next comes the telogen phase, which usually lasts about 2 to 3 months.

Growth has already stopped, and the follicle remains relatively inactive while temporarily retaining the previously formed hair.

This stage is especially important for understanding why hair loss can seem sudden.

The problem may have started months before you saw the hair falling out

An illness with a fever, surgery, significant weight loss, changes after pregnancy, certain nutritional deficiencies, or physiological stress situations can cause a larger number of follicles to enter the telogen phase at approximately the same time.

The hair does not necessarily shed at that moment.

It may happen months later.

When a high number of follicles enter the telogen phase prematurely and subsequently shed, what we know as telogen effluvium can occur.

This is why, in the event of sudden hair loss, a dermatologist may ask what happened in your life or health several months ago.

Exogen phase: now the hair actually sheds

This is where what you can finally see happens.

During the exogen phase, the hair shaft that remained in the follicle is released and finally falls out.

It may appear on your brush, pillow, clothes, or in the shower.

And here there is a fundamental difference:

just because a hair sheds does not automatically mean you have lost the follicle.

If the follicle remains functional, it can restart an anagen phase and begin producing a new hair.

The American Academy of Dermatology points out that losing approximately 50 to 100 hairs a day can be part of normal shedding.

So, when should you worry about hair loss?

Counting every hair you lose can be impractical. It is more useful to observe if there is a change compared to what is usual for you.

For example, suddenly noticing much more hair during your shower, observing that your ponytail feels thinner, that your part is widening, that your hairline is receding, or that areas with lower density are appearing are reasons to seek a dermatological assessment.

And this is important because not all hair loss has the same origin.

Telogen effluvium, androgenetic alopecia, and alopecia areata, for example, affect hair through different mechanisms and do not necessarily require the same approach.

In androgenetic alopecia, the cycle also begins to change

Androgenetic alopecia does not simply consist of "too much hair falling out."

In susceptible follicles, the influence of androgens—especially dihydrotestosterone (DHT)—contributes to a progressive process of follicular miniaturization.

With successive cycles, the anagen phase can shorten, and the hairs produced by those follicles can become progressively shorter and thinner.

This explains why many people do not experience spectacular hair loss overnight. Sometimes, the first thing they notice is that their hair no longer has the same density or thickness as before.

What does Minoxidil have to do with the hair cycle?

This is where understanding the previous phases makes even more sense.

Minoxidil is one of the most studied treatments for certain types of hair loss. Its mechanism is complex and is still being investigated, but it has been linked to effects on the follicle and the prolongation of the anagen phase.

This also explains why it makes no sense to evaluate a hair treatment after just a few days.

We are talking about a biological cycle that occurs over months and years. The follicle needs to go through different stages before the changes can become visible.

That is why consistency and proper monitoring are essential.

At Pharma Grow, we offer 1 mg, 2.5 mg, and 5 mg Oral Minoxidil formulations. The appropriate presentation and dosage must be determined through professional assessment based on each person's diagnosis, history, and characteristics.

Frequently asked questions about the hair cycle

Does a hair falling out mean it won't grow back?

Not necessarily. Shedding is part of the natural cycle. If the follicle remains functional, it can start a new anagen phase and produce another hair.

What is the longest hair phase?

The anagen phase. On the scalp, it can last for several years, and it is during this period that the hair is actively growing.

Why might I notice hair loss months after a stressful period?

Because certain events can cause a larger number of follicles to transition into the telogen phase. Shedding occurs later, so there can be an interval of several months between the trigger and the visible increase in hair loss.

Is losing hair every day normal?

Yes. Hair is continuously renewed, and a certain amount of daily shedding is physiological. The AAD uses approximately 50–100 hairs a day as a general reference, although individual variations exist.

Does Minoxidil act immediately?

No. Hair growth treatments need time because they work within a slow biological cycle. The response must be evaluated over months and under professional supervision, not after a few days.

The hair you see falling out today can tell a story from months ago

Your hair does not just grow and fall out.

As you read this, some follicles are in the anagen phase, actively producing hair. Others are going through the catagen transition. A portion is resting during the telogen phase, while certain hairs are finally shedding in the exogen phase.

Afterward, for a healthy follicle, the cycle can begin again.

That is why, if you have been losing more hair lately, looking only at what was left on your brush tells only part of the story.

The important question is:

what is happening with the cycle of your follicles?

Identifying the cause of a change in hair loss allows you to choose an appropriate approach and avoid treatments based solely on assumptions.