OUR IN & OUT TIPS FOR FASTER, STRONGER HAIR GROWTH
Your hair grows on average 1 to 1.5 cm per month, or around 12 to 15 cm per year. But this rate varies greatly from one person to another depending on genetics, diet, stress, and the care you give it. If you dream of long, healthy hair without waiting years, the good news is that there are concrete solutions to speed up growth and strengthen your hair from the inside as well as the outside. In this complete guide, you will discover how hair growth really works, the scientifically proven dietary supplements that help stimulate growth (collagen, proteins, vitamins), the external treatments that truly make a difference, and above all: the common mistakes that sabotage your efforts without you even realizing it. Get ready to finally understand how to achieve longer, stronger, shinier hair through a holistic IN & OUT approach.
UNDERSTANDING HAIR GROWTH
Before diving into solutions, it is essential to understand how your hair actually grows. This knowledge will help you adopt the right habits at the right time and set realistic expectations.
THE HAIR LIFE CYCLE
Your hair does not grow continuously throughout your life. It follows a precise cycle in three distinct phases:
1. Anagen Phase (Growth Phase) - 2 to 7 years
This is the active phase during which the hair grows continuously. Around 85 to 90% of your hair is in this phase at any given time. The length of this phase determines the maximum length your hair can reach. It is during this period that hair follicles are most receptive to nutrients and stimulating treatments.
2. Catagen Phase (Transition Phase) - 2 to 3 weeks
The hair stops growing and detaches from the hair follicle. Around 1 to 2% of your hair is in this phase. The follicle shrinks and the hair moves up toward the surface. This is a resting phase during which no treatment can influence growth.
3. Telogen Phase (Shedding Phase) - 2 to 4 months
The hair falls out naturally to make way for a new one. Around 10 to 15% of your hair is in this phase. It is completely normal to lose 50 to 100 hairs a day at this stage. A new hair is already starting to grow beneath the scalp.
What you need to remember: You cannot force a hair in the catagen or telogen phase to grow. The goal is to extend the anagen phase as much as possible and create the best conditions so that the new hair growing in is strong and healthy.
NORMAL SPEED VS MAXIMUM SPEED
Average natural growth rate: 1 to 1.5 cm per month for most people
12 to 18 cm per year depending on genetics
Asian hair grows slightly faster (1.3 cm/month on average) than Caucasian hair (1.2 cm/month) or Afro hair (0.9 cm/month)
Maximum achievable growth rate:
With an optimal approach (nutrition, supplements, care, protection), you can reach 1.5 to 2 cm per month, or around 18 to 24 cm per year. It is biologically impossible to go beyond this speed.
Why this limit?
The cells of the hair follicle have a genetically programmed maximum division rate. You cannot accelerate this process beyond a certain threshold, but you can optimize the conditions so your hair reaches its maximum potential.
Maximum length:
Your hair’s final length depends on the duration of your anagen phase. If your anagen phase lasts 3 years, your hair will reach a maximum of 36 to 45 cm (3 years × 1-1.5 cm/month × 12 months). If it lasts 7 years, you may reach 84 to 126 cm. This is genetic, but certain factors can slightly extend this phase.
FACTORS THAT SLOW DOWN GROWTH
Many factors can slow your hair growth or cause premature shedding. Identifying them is the first step in addressing them.
1. Nutritional Deficiencies
Lack of protein: Hair is made up of 95% keratin, a protein. Without sufficient protein intake (minimum 0.8 g per kilogram of body weight), keratin production is compromised.
Iron deficiency: Iron-deficiency anemia is one of the most common causes of hair loss in women. Iron carries oxygen to the hair follicles.
Lack of biotin (vitamin B8): Essential for keratin synthesis.
Vitamin D deficiency: Activates resting hair follicles and stimulates the growth of new hair.
Zinc deficiency: Regulates the hair growth cycle and repairs damaged follicles.
2. Hormonal Imbalances
Excess androgens: DHT (dihydrotestosterone) miniaturizes hair follicles, causing androgenetic alopecia.
Thyroid disorders: Hypothyroidism slows metabolism and hair growth.
Polycystic ovary syndrome (PCOS): Causes hair loss and slower growth.
Postpartum: The hormonal drop after childbirth pushes many hairs into the telogen phase at the same time.
3. Chronic Stress
Prolonged stress increases cortisol, which:
Disrupts the hair cycle by prematurely pushing hairs into the telogen phase (telogen effluvium)
Reduces the absorption of essential nutrients
Decreases blood circulation to the scalp
Increases inflammation in the follicles
4. Poor Blood Circulation
The scalp needs good blood flow to deliver oxygen and nutrients to the follicles. Poor circulation (sedentary lifestyle, muscle tension in the scalp) limits nourishment to the roots.
5. Scalp Inflammation
Seborrheic dermatitis, psoriasis, eczema: create a hostile environment for hair growth
Oily or clogged scalp: excess sebum suffocates the follicles
Irritating products: harsh sulfates, heavy silicones, drying alcohols
6. External Factors
Excessive heat: blow dryers, straighteners, curling irons weaken the hair fiber and cause breakage
Repeated chemical coloring: weakens the hair structure
Tight hairstyles: buns, braids, ponytails pull on the roots (traction alopecia)
Nighttime friction: cotton pillowcases create friction that breaks the hair
Chlorinated or hard water: dries out and weakens the fiber
7. Aging
With age, the anagen phase naturally shortens, follicles produce finer hair, and the growth rate decreases slightly.
IN: SUPPLEMENTS THAT PROMOTE GROWTH FROM WITHIN
Beautiful hair starts on your plate and is strengthened with targeted supplements. Your hair follicles need specific nutrients to produce strong, long, shiny hair. Here are the 3 essential nutritional pillars to stimulate growth from within.
TAKE COLLAGEN
Collagen is a true hair treatment. It works deeply to strengthen the hair and reduce hair loss. Taking collagen increases the production of keratin, the structural protein that makes up nails and hair. Your hair (and your nails) will therefore grow faster and become denser and shinier. The first effects of regular collagen intake are actually visible on the hair and nails before they show on the skin.
Learn more about collagen supplements in our features.
How does it work?
Collagen provides the essential amino acids (proline, glycine, hydroxyproline) needed for the production of keratin, the protein that makes up 95% of your hair.
It stimulates keratin production by the hair follicles.
It strengthens the structure of the hair shaft (less breakage = hair that grows longer).
It improves blood circulation in the scalp (better nourishment for the follicles).
It extends the anagen (growth) phase of the hair cycle.
Scientific studies:
A 2017 study showed that taking collagen for 90 days significantly increased:
Hair density (+13%)
Hair diameter (+15%)
Growth rate
Expected results:
1 month: Shinier hair, less breakage
3 months: Faster growth (+30%), improved density
6 months: Visible transformation (length, thickness, quality)
- Holi (Mane) - AGENT NATEUR
- Original Natural Marine Collagen - VIDA GLOW
- Beauty Collagen Blend - KIKI HEALTH
EAT MORE PROTEIN
Hair is made up of 95% keratin, a protein. Without sufficient protein intake, your body simply cannot produce strong, healthy hair.
Why Are Proteins Essential?
1. Keratin production
Keratin is synthesized from amino acids supplied by dietary proteins. No protein = no keratin = fine, brittle hair and slower growth.
2. Repair of hair follicles
Proteins nourish and repair follicle cells, ensuring continuous production of healthy hair.
3. Prevention of hair loss
A protein deficiency prematurely pushes hair into the telogen phase (shedding). It is one of the most common causes of diffuse hair loss.
4. Structure and elasticity
Proteins give hair its strength, elasticity, and ability to return to its shape after stretching.
TAKE SPECIFIC HAIR SUPPLEMENTS
Taking targeted dietary supplements helps promote healthy hair growth by providing the nutrients your hair needs. These supplements help create the healthy environment necessary for growth and proper hair development. Zinc, Selenium, Biotin...
He Shou Wu, an adaptogenic plant rich in antioxidants, is very well known for fighting hair loss and strengthening and hydrating the hair.
MSM activates cell renewal and helps build collagen, keratin, and cartilage.
OUT: HEALTHY, SHINY HAIR STARTS WITH A HEALTHY SCALP
MASSAGE YOUR SCALP WITH A SCALP BRUSH OR HIGH-TECH TOOLS
The soft bristles of these brushes gently remove dead skin cells and impurities, helping restore a healthy, balanced scalp. They also stimulate microcirculation, which promotes the growth of healthy hair.
USE SERUMS THAT PURIFY THE SCALP AND STIMULATE GROWTH
Applying a suitable serum promotes shine, scalp health, and therefore hair growth. To achieve truly healthy hair, start by taking care of your scalp. Serums are a true care ritual, both protective and growth-boosting. They smooth, soothe, and promote growth.
PROTECT YOUR HAIR FROM HEAT
You should limit the use of blow dryers and straighteners as much as possible. Heat damages your hair, making it dry and brittle. If you have to use one of these tools, make sure to protect your hair beforehand with a product that helps reduce damage.
REALISTIC RESULTS TIMELINE
How long does it take to see concrete results? Here is what you can expect with an optimal IN & OUT approach (supplements + external care).
After 1 Month
What is happening:
- Your hair follicles begin receiving essential nutrients
- Your scalp gradually becomes more balanced (less oily or less dry)
- The anagen (growth) phase is slightly stimulated
Visible results:
- Shinier hair (better-nourished cuticles)
- Less breakage during brushing (stronger fiber)
- Healthier scalp (less itching, reduced dandruff)
- Slight baby hair growth: very fine new hairs begin to grow (especially if you had deficiencies)
- Measurable growth: +1 to 1.5 cm (normal speed, not yet accelerated)
What you feel:
Your hair feels more “alive,” less dull. You may still be losing as much hair as before (telogen cycle still ongoing), but the new hair coming in is stronger.
After 3 Months
What is happening:
- New hairs (anagen phase) grow with a stronger structure thanks to proteins, vitamins, and minerals
- Hair shedding decreases (hairs in the telogen phase fall out less quickly)
- Blood circulation in the scalp improves (regular massages)
Visible results:
- Faster growth: +4 to 6 cm total (compared with 3-4.5 cm normally)
- Visibly improved density: thicker baby hair, fewer sparse areas
- Noticeably stronger hair: better resistance to handling
- 30-50% reduction in shedding: you lose much less hair in the shower and when brushing
- Optimal shine and softness: transformed texture
- Stronger nails (collagen bonus): a sign that collagen is working
What you feel:
People around you start to notice: “Your hair grew fast!” or “It looks so much better!” You feel motivated to continue.
The critical milestone: Many people give up before 3 months. But that is exactly when results really take off.
After 6 Months and Beyond
What is happening:
- Up to 3 complete hair cycles: hairs that were in the telogen (shedding) phase on day 0 have been replaced by strong new hairs
- The anagen phase is prolonged (longer lifespan)
- Hair follicles function at their optimal capacity
Visible results:
- Total growth: +9 to 12 cm (compared with 6-9 cm normally) = +30-50% vs natural speed
- Significantly increased length: dramatic difference, especially on short to mid-length hair
- Maximum density: thicker hair, more volume, fewer thin areas
- Exceptional quality: shine, elasticity, and strength at their best
- Stabilized shedding: normal daily loss (50-80 hairs/day max)
- Regrowth in weakened areas: temples and middle part look fuller
What you feel:
A visible, lasting transformation. You have reached your length goals or are well on your way. The routine has become second nature.
After 6 months:
Continue supplements (collagen, vitamins) for maintenance: ongoing intake, not a temporary course
Maintain your care routine: healthy scalp, heat protection, balanced routine
Lasting results: as long as you maintain your good habits
FAQ: Your Questions About Hair Growth
Does cutting your hair really make it grow faster?
NO, that is a myth. Hair grows from the follicle under the scalp, not from the ends. Cutting the lengths has absolutely no effect on the growth rate at the root. It is like believing that trimming the branches of a tree makes the roots grow faster: it makes no biological sense.
Cutting damaged ends (split ends, brittle hair) improves the appearance and health of the hair. It seems to grow “better” because it breaks less, but the actual growth rate remains identical (around 1 cm/month).
Should you still trim it?
Yes, but only to remove split ends which, if left uncut, travel up the hair fiber and weaken the entire length. Trim 5-10 mm every 4-6 months, no more.
What is the ideal washing frequency to promote growth?
It depends on your hair type:
Normal to dry hair: 2 times a week
Oily hair: 3 times a week (avoid washing too frequently, which stimulates the sebaceous glands even more)
Curly/coily hair: once a week is enough (this hair type is naturally drier)
Sensitive scalp: 2 times a week maximum with an ultra-gentle shampoo
Tip: If your hair gets oily quickly, it is often because you wash it too often. Gradually space out shampoos over 2-3 weeks to rebalance sebum production. Another common cause: your ends are too dry. The scalp then produces excess sebum to compensate and try to hydrate the dehydrated lengths. Solution: properly hydrate your ends with an oil or nourishing mask (avoiding the roots), and you will see that your roots get oily less quickly. A balanced scalp = hydrated ends.
How long should you take dietary supplements?
Short answer: CONTINUOUSLY, not as a temporary course.
Contrary to popular belief, hair supplements (collagen, biotin, vitamins) do NOT work as a 1-3 month course. As soon as you stop, your body returns to its initial functioning and growth slows down.