30 September 2025 · By Alicia Backhouse

The stages of hair growth: How the hair growth cycle works

If you’ve noticed a few extra hairs in your hairbrush or strands in the shower, don’t worry. Shedding is a completely normal and healthy part of the hair growth cycle, with those fallen strands making way for new healthy growth, maximised by LED therapy.

Understanding the hair growth cycle

The hair growth cycle features 4 phases—3 stages of growth followed by a shedding period:

Anagen Phase

The active growth phase, during which cells divide at the root to form strands. On the scalp, this phase lasts 3-7 years on average, determining the potential length of hair, typically growing just over 1cm a month.

LED red light therapy encourages hair follicles to enter and stay in the anagen (growth) phase by increasing blood flow and cellular activity, energising cells and delivering oxygen and nutrient-rich blood to the scalp to fuel healthy growth.

Catagen Phase

Lasting only a few weeks, this stage marks the end of hair growth as the follicle starts to shrink and detach from the blood supply essential for growth.

Telogen Phase

The resting phase, lasting 2-3 months, during which the hair follicle is inactive. Each hair is held in place by the root, which develops a club shape to anchor it in place until a new hair begins to form.

By boosting cell activity and blood flow, red light therapy helps to shorten this phase, triggering a return to the anagen phase and new hair growth. 

Exogen Phase

As old hairs are released and fall from the scalp. Lasting 2-3 months, this is known as the shedding phase and is an essential part of the cycle, preparing follicles for the growth phase to begin and the cycle to continue.

Woman using the CurrentBody LED hair growth helmet during anagen phase

Factors that affect the hair growth cycle

The length of each stage of the cycle is affected by a combination of internal and external factors which can disrupt its natural rhythm and affect growth.

Genetics

Hereditary conditions like male or female pattern baldness, caused by a sensitivity to sex hormone dihydrotestosterone (DHT), shorten the growth phase with each cycle. This causes follicles to shrink, producing finer, shorter strands until growth stops completely.

Hormones

Estrogen and progesterone help to extend the growth stage and balance DHT levels. Hormonal changes due to pregnancy, menopause, or changing thyroid function can all cause hormones to fall out of balance, reducing the potential for growth.

Lifestyle

A healthy lifestyle is key to healthy hair growth. Nutrient deficiencies, stress and lack of sleep are all known to slow growth, depriving follicles of nutrients and reducing the body’s ability to regenerate, pushing follicles into the resting phase.

Supporting healthy hair growth with LED therapy

At-home red light therapy devices offer a science-backed hair growth solution. Prolonging the growth phase, reactivating inactive follicles and improving overall scalp health, devices like the CurrentBody Skin LED Hair Growth Helmet strengthen and boost follicles for thicker, fuller locks.

To supercharge your treatments and take your growth to the next level, complement treatments with a healthy, balanced diet, rich in protein and vitamins and minerals essential for forming strong, healthy strands. This includes iron, vitamin D and biotin—the building blocks of hair.

For best results, follow LED treatments with scalp massage to boost circulation, and opt for gentle products and low tension hairstyles to protect new growth.

Maximise your hair growth cycle with LED red light therapy

Instead of repeating the same cycle of growth to shedding and back again, invest in LED technology and take control of your hair health. Lengthening the growth phase and stretching the cycle, red light therapy fuels follicles for fuller, thicker, longer locks.

Woman holding an LED hair growth helmet to use during the growth phase of the cycle



currentbody-logo
Alicia Backhouse Beauty Editor

Alicia is a beauty content specialist based in Manchester with over 5 years of experience in the beauty industry. Having worked with various cult skincare and haircare brands, Alicia now works in-house at CurrentBody Skin, calling on her own experiences with problem skin and industry expertise to inform her writing and express her passion for beauty technology.

Prev Post Why is my hair falling out? Common hair loss causes