How does the hair life cycle work?

Perhaps not everyone’s aware of it, but contrary to urban myths and modern belief, hair is not eternal. Healthy hair in solid condition will stay on our head for several years, but sooner or later it will fall out. It is a natural process and you shouldn’t worry about it, because in place of an old hair strand, another one will grow and flourish. The hair life cycle usually lasts from 2 to 7 years. A good analogy would be to compare it to a slow skin-shedding process, whereby within a matter of months we replace the old cells with the new ones.

We lose our hair every day

Hair falls out everyday. It’s no secret and everyone experiences it, in greater or lesser amounts. But losing long hair is undeniably the most noticeable, because they usually get stuck in all places around our house – a tub, a sink or a brush. This is especially the case if your hair is thick and dark. If you’re a woman, you’ll know exactly what we mean – if you’re a man with a female partner, you’ll be familiar with this issue as well!

Everyone loses approximately 50 to 80 hairs per day, and for some that number may rise up to 150. But each hair is usually replaced by a new strand i.e. the root is created because of the follicles pushing out new cells. But the follicles produce new growth only at the end of the third phase of the hair life cycle. In addition to this phase, we can distinguish two more stages of the cycle.

Hair life cycle – anagen, catagen and telogen phases

Hair grows from the hair follicles at different times and rates. If every follicle functioned the same way, sometimes we’d end up with lush hair, and at other times we wouldn’t have any hair at all. So, the hair growth process is actually pretty irregular. Therefore, in order to keep the quality of our hair balanced, the hair follicles work at varied rates, so at one single time, we may have growing hair in the anagen, catagen and telogen phases simultaneously. However, most of our hair (in fact as much as 90%), is in the first phase at once.

Phase I – Anagen

As was aforementioned, the hair life cycle is divided into three phases – the first of which is anagen. It is also called the ‘intense growth stage’, because it is then that our hair is actively growing about 1 cm per month. The anagen phase usually lasts from one to four years.

Phase II – Catagen

The catagen phase represents the time when hair gradually stops growing, and prepares itself to fall out. This phase, also known as the ‘transitional stage’, whereby the follicle no longer produces the hair cells, and slowly withdraws itself from the surface of the scalp. This usually lasts about 2-3 weeks and occurs almost straight after the first stage is completed.

Phase III – Telogen

The last phase, called the telegen, (also known as the ‘resting phase’), represents time when the hair does not grow at all, and the hair follicles simply rest. This usually takes about three months. The hair is still attached to the scalp, but it falls out very easily, e.g. during daily activities – washing or brushing our hair or even running etc. Sometimes there doesn’t have to be a direct reason to make the hair fall out, as it simply falls out by itself, either naturally or due to being pushed out by new, re-growing hair cells. Then the follicles start to produce new hair cells and thus the new anagen phase begins.

How many times during the hair life cycle do the follicles create new hair?

The hair life cycle is usually repeated approximately 25 to 30 times during our lifetime. Of course, provided that the follicles are not destroyed or damaged as a result of an illness, injury or long-term exposure to harmful treatments. What’s more, the cycle cannot be disrupted by hormonal disturbances, otherwise the repeating process will be lower.