Contents:
- The Three Stages of Hair Growth: Anagen, Catagen, and Telogen
- Anagen: The Active Growth Phase
- Catagen: The Transition Phase
- Telogen: The Resting and Shedding Phase
- What Influences Hair Growth Rate and Duration
- Genetics and Ethnicity
- Nutrition and Micronutrients
- Hormones and Stress
- Age
- Sustainable Practices for Healthy Hair Growth
- Minimise Damage During Growth
- Scalp Care as Foundation
- Choose Growth-Supporting Ingredients Wisely
- Regional Differences in Hair Care
- Frequently Asked Questions
- How long does it take to grow shoulder-length hair?
- Can you speed up hair growth?
- Why does my hair shed more in autumn?
- Does cutting hair make it grow faster?
- What’s the difference between hair growth and hair retention?
- Moving Forward With Your Hair Growth Journey
Have you ever wondered why your hair seems to grow faster at certain times of the year, or why some people’s hair reaches past their shoulders while others struggle to maintain length? The answer lies in understanding the remarkable biological process of how hair grows—a cycle that’s far more complex than simply letting time pass.
Your hair isn’t growing steadily from one moment to the next. Instead, it follows a precise three-stage cycle that repeats throughout your lifetime. Understanding these stages transforms how you approach hair care, allowing you to work with your hair’s natural rhythm rather than against it.
The Three Stages of Hair Growth: Anagen, Catagen, and Telogen
Hair growth operates through three distinct phases, each lasting different lengths of time and playing a crucial role in maintaining your hair’s health and volume.
Anagen: The Active Growth Phase
The anagen phase is where the magic happens. During this stage, your hair cells are dividing rapidly at the hair root, and new cells push older cells upward, creating the physical growth you see. This phase typically lasts between two to seven years, though genetics plays a significant role in determining your personal timeline. Studies show that people of East Asian descent often experience longer anagen phases—up to ten years—which partially explains why long, thick hair is more common in these populations. Meanwhile, individuals with European heritage may experience shorter cycles of three to five years.
The length of your anagen phase directly determines your maximum hair length. If your hair grows approximately 15 centimetres per year—a commonly cited measurement—then someone with a five-year anagen phase could theoretically reach about 75 centimetres of hair before entering the next phase. This is why some people naturally find it easier to grow longer hair, whilst others may struggle to grow hair beyond a certain length.
During anagen, your hair is at its strongest and most resilient. The cells are tightly bound together, and the hair shaft is receiving consistent nourishment from the blood vessels surrounding the hair follicle. This is the ideal time to engage in growth-promoting practices.
Catagen: The Transition Phase
After the anagen phase ends, your hair enters catagen—a short, transitional stage lasting roughly two to three weeks. During this phase, growth slows dramatically, and the hair follicle begins to shrink. The hair root detaches from the blood supply, meaning the hair is no longer actively nourished. This is a natural resting period before the final phase begins.
You won’t notice much happening during catagen—it’s a quiet phase where your hair isn’t visibly changing. However, it’s preparing for the release that comes next.
Telogen: The Resting and Shedding Phase
Telogen is the resting phase, lasting approximately two to four months. During this time, the hair detaches fully from the follicle and sits dormant. You might be surprised to learn that losing 50 to 100 hairs per day is completely normal—these are telogen hairs making their exit to make room for new growth.
What happens if telogen extends beyond its normal timeframe? Extended telogen periods can lead to telogen effluvium, a condition where hair shedding increases significantly. This can be triggered by stress, hormonal changes, nutritional deficiencies, or major life events. However, the good news is that this condition is usually temporary, and hair typically re-enters the growth cycle once the triggering factor is resolved.
What Influences Hair Growth Rate and Duration
Your hair growth isn’t entirely fixed—several factors influence both how quickly your hair grows and how long your anagen phase lasts.
Genetics and Ethnicity
Your genes are the primary driver of hair growth patterns. Not only do they determine the length of your growth phases, but they also influence your hair thickness, texture, and colour. Regional variations are notable: people in Nordic regions tend to have finer hair but faster growth rates, whilst individuals of African descent often experience slower linear growth but may have natural protective curl patterns that require different care strategies.
Nutrition and Micronutrients
Hair growth demands specific nutrients. Biotin, iron, zinc, and vitamin D are particularly important—deficiencies in any of these can slow growth or increase shedding. A 2024 study found that individuals supplementing with biotin saw modest improvements in hair strength and thickness, though the effects weren’t dramatic. Protein is equally crucial; your hair is made primarily of a protein called keratin, so ensuring adequate protein intake (approximately 0.8 grams per kilogramme of body weight daily) supports continuous growth.
For those in the UK, seasonal variations in vitamin D availability mean supplementation during autumn and winter months can be beneficial for hair health.
Hormones and Stress
Hormonal fluctuations affect hair growth significantly. Pregnancy, thyroid disorders, and menopause can all trigger changes in the hair growth cycle. Chronic stress elevates cortisol levels, which can prematurely push hair from anagen into telogen, leading to noticeable shedding weeks after the stressful event.
Age
Hair growth naturally slows with age. People in their teens and twenties typically experience optimal growth rates, whilst those over 50 may notice slower growth and increased greyness as melanin production decreases in hair follicles.
Sustainable Practices for Healthy Hair Growth
Understanding your hair’s growth cycle opens doors to more eco-conscious hair care. Rather than constantly chasing quick fixes with expensive products, you can work with your biology.
Minimise Damage During Growth
During anagen, your hair is actively growing but also vulnerable to damage. High heat styling, frequent chemical treatments, and tight hairstyles can damage the hair shaft before it’s had time to reach its full potential length. Reducing reliance on heat tools—perhaps air-drying hair twice weekly instead of blow-drying daily—reduces your environmental footprint whilst protecting growing hair.
Scalp Care as Foundation
A healthy scalp is essential for optimal hair growth. Gentle cleansing (two to three times weekly for most people) maintains the scalp environment where hair roots thrive. Massaging your scalp for five minutes daily can increase blood flow to hair follicles, potentially improving nutrient delivery. This practice costs nothing and has no environmental impact, making it ideal for sustainable hair care.
Choose Growth-Supporting Ingredients Wisely
Rather than replacing your entire routine with expensive supplements, focus on evidence-backed ingredients. Niacinamide can improve scalp health, whilst peptides support keratin production. Many of these ingredients are available in reasonably priced UK brands ranging from £5 to £20 per product, eliminating the need for luxury alternatives.
Regional Differences in Hair Care
Geography influences not just genetics, but environmental factors affecting hair growth. In the damp climate of Scotland and Northern England, hair tends to absorb moisture differently than in the drier South, requiring adjusted hydration strategies. The West Coast experiences harder water in some areas, which can leave mineral deposits on hair, subtly slowing perceived growth and dulling shine. Understanding your local water chemistry and climate helps you adapt your routine accordingly.
Frequently Asked Questions
How long does it take to grow shoulder-length hair?
At an average growth rate of 15 centimetres annually, shoulder-length hair (approximately 40 centimetres) typically takes 2.5 to 3 years from a very short cut. This assumes consistent growth without major damage or disruption.
Can you speed up hair growth?
You cannot fundamentally accelerate the biological growth rate, but you can optimise conditions for healthy growth. Ensuring adequate protein, iron, biotin, and vitamin D; minimising damage; managing stress; and maintaining scalp health all support your hair reaching its genetic potential.
Why does my hair shed more in autumn?
Many people experience increased shedding in autumn, likely related to seasonal changes in daylight and temperature, which trigger more hairs to enter telogen simultaneously. This is typically temporary and normalises within a few months.
Does cutting hair make it grow faster?
No—cutting removes damaged ends but doesn’t affect the growth rate at the root. However, regular trims every 8 to 12 weeks prevent split ends from travelling up the hair shaft, allowing you to retain length more effectively.
What’s the difference between hair growth and hair retention?
Hair growth refers to new cells being produced at the root, whilst hair retention means keeping the length you’ve grown by preventing breakage and damage. Many people blame slow growth when they’re actually experiencing poor retention—a problem solved through damage prevention rather than growth acceleration.
Moving Forward With Your Hair Growth Journey
Now that you understand the biological reality of how hair grows, you’re equipped to make informed decisions about your hair care. Rather than chasing unproven claims, you can focus on what science supports: protecting your anagen phase from damage, nourishing your body with essential nutrients, managing stress, and maintaining a healthy scalp environment.
Your hair didn’t fail you—it’s simply following the genetic blueprint you inherited. By respecting this natural cycle and working within it, you’ll likely see improvements in both length and quality. Start with one change this month: perhaps a scalp massage routine or a reduction in heat styling. Small, consistent actions compound over your hair’s growth cycles, delivering noticeable results within six to twelve months.
The best time to start optimising your hair growth was years ago. The second best time is today.
