OUR IN & OUT TIPS FOR FASTER AND STRONGER GROWTH
Your hair grows on average 1 to 1.5 cm per month, or about 12 to 15 cm per year. But this rate varies enormously from person to person depending on genetics, diet, stress, and the care you give it. If you dream of a long, healthy mane without waiting years, good news: there are concrete solutions to accelerate growth and strengthen your hair from the inside out. In this comprehensive guide, you'll discover how hair growth really works, the scientifically proven dietary supplements to stimulate growth (collagen, proteins, vitamins), the external treatments that 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, and shinier hair with a holistic IN & OUT approach.
UNDERSTANDING HAIR GROWTH
Before trying any solutions, it's essential to understand how your hair actually grows. This knowledge will allow you to adopt the right practices at the right time and have realistic expectations.
THE HAIR LIFE CYCLE
Your hair doesn't 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 hair grows continuously. Approximately 85 to 90% of your hair is in this phase at any given time. The duration 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. Approximately 1 to 2% of your hair is in this phase. The follicle shrinks and the hair moves back towards the surface. This is a resting phase during which no treatment can influence growth.
3. Telogen Phase (Hair Shedding Phase) - 2 to 4 months
Hair naturally falls out to make way for new growth. Approximately 10 to 15% of your hair is in this phase. It's perfectly normal to lose 50 to 100 hairs a day at this stage. A new hair is already beginning to grow beneath the scalp.
Key takeaway: You cannot force a hair in the catagen or telogen phase to grow. The goal is to prolong the anagen phase as much as possible and create the best conditions for the new hair that grows to be strong and healthy.
NORMAL SPEED VS MAXIMUM SPEED
Natural average speed:
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 (1.2 cm/month) or Afro (0.9 cm/month) hair.
Maximum achievable speed:
With an optimal approach (nutrition, supplements, care, protection), you can achieve 1.5 to 2 cm per month, or approximately 18 to 24 cm per year. It is biologically impossible to exceed this rate.
Why this limit?
The cells in 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 that your hair reaches its maximum potential.
Maximum length:
The final length of your hair depends on the duration of your anagen phase. If your anagen phase lasts 3 years, your hair will reach a maximum length of 36 to 45 cm (3 years × 1-1.5 cm/month × 12 months). If it lasts 7 years, you could reach 84 to 126 cm. This is genetic, but certain factors can slightly prolong this phase.
FACTORS THAT SLOW GROWTH
Many factors can hinder hair growth or cause premature hair loss. Identifying them is the first step to addressing the problem.
1. Nutritional Deficiencies
Protein deficiency: Hair is composed of 95% keratin, a protein. Without sufficient protein intake (minimum 0.8g 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 transports oxygen to the hair follicles.
Biotin (vitamin B8) deficiency: Essential for keratin synthesis.
Vitamin D deficiency: Activates hair follicles in the resting phase 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 down metabolism and hair growth.
Polycystic ovary syndrome (PCOS): Causes hair loss and slowed growth.
Postpartum: The hormonal drop after childbirth causes many hairs to switch to the telogen phase simultaneously.
3. Chronic Stress
Prolonged stress increases cortisol, which:
Disrupts the hair cycle by prematurely pushing hair into the telogen phase (telogen effluvium)
Decreases the absorption of essential nutrients
Reduces blood flow to the scalp
Increases inflammation of the follicles
4. Poor Blood Circulation
The scalp needs good blood flow to deliver oxygen and nutrients to the follicles. Poor circulation (due to a sedentary lifestyle or muscle tension in the scalp) limits the supply of nutrients to the roots.
5. Scalp Inflammation
Seborrheic dermatitis, psoriasis, eczema: Create an environment hostile to hair growth
Oily or clogged scalp: Excess sebum suffocates the follicles
Irritating products: Harsh sulfates, heavy silicones, drying alcohols
6. External Factors
Excessive heat: Hair dryers, straighteners, and 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 hair
Chlorinated or hard water: Dries out and weakens the fiber
7. Aging
With age, the anagen phase naturally shortens, the follicles produce finer hairs and the growth rate decreases slightly.
IN: SUPPLEMENTS THAT PROMOTE GROWTH FROM WITHIN
Beautiful hair starts with what you eat and is enhanced with targeted supplements. Your hair follicles need specific nutrients to produce strong, long, and shiny hair. Here are the 3 essential nutritional pillars to stimulate growth from within.
TAKE COLLAGEN
Collagen is a true hair treatment. It works deep down to strengthen hair and limit hair loss. Taking collagen increases the production of keratin, the structural protein that makes up nails and hair. Your hair (and nails) will therefore grow faster and be thicker and shinier. The first effects of regular collagen intake are visible first on the hair and nails, then on the appearance of the skin.
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 the production of keratin by the hair follicles.
It strengthens the structure of the hair shaft (less breakage = longer growing hair).
It improves blood circulation in the scalp (better nutrition of the follicles).
It prolongs 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%)
The growth rate
Expected results:
1 month: Shinier hair, less breakage
3 months: Accelerated growth (+30%), improved density
6 months: Visible transformation (length, thickness, quality)
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 Construction
Keratin is synthesized from amino acids obtained from dietary proteins. No protein = no keratin = thin, brittle hair, slowed growth.
2. Repair of hair follicles
Proteins nourish and repair follicle cells, ensuring continuous production of healthy hair.
3. Fall prevention
A protein deficiency causes hair to prematurely enter the telogen phase (shedding). This 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 can promote healthy hair growth by providing the nutrients hair needs. These supplements help create a healthy environment necessary for hair growth and development. Zinc, Selenium, Biotin...
He Shou Wu, an adaptogenic plant rich in antioxidants, is well known for combating hair loss, strengthening and moisturizing hair.
MSM activates cell renewal and helps build collagen, keratin, and cartilage.
OUT: HEALTHY, SHINY HAIR STARTS WITH A HEALTHY SCALP
MASSAGE YOUR HAIR WITH A SCALP BRUSH OR HIGH-TECH TOOLS
The soft bristles of these brushes gently remove dead skin cells and impurities, helping to restore a healthy and balanced scalp. They also stimulate microcirculation, which promotes healthy hair growth.
USE SERUMS THAT WILL CLEANSE THE SCALP AND STIMULATE GROWTH
Applying a suitable serum promotes shine, scalp health, and therefore hair growth. To have healthy hair, start by taking care of your scalp. Serums are a true care ritual, protecting and boosting growth. They smooth, soothe, and promote growth.
PROTECT YOUR HAIR FROM THE HEAT
You should limit the use of hair dryers and straighteners as much as possible. Heat damages your hair, making it dry and brittle. If you must use one of these tools, be sure to protect your hair beforehand with a product that reduces damage.
REALISTIC TIMELINE OF RESULTS
How long does it take to see concrete results? Here's what you can expect with an optimal IN & OUT approach (supplements + external treatments).
After 1 Month
What's happening:
- Your hair follicles are starting to receive essential nutrients
- The scalp gradually balances out (becoming less oily or less dry)
- The anagen (growth) phase is slightly stimulated
Visible results:
- Shinier hair (better nourished cuticles)
- Less breakage when brushing (reinforced fiber)
- Healthier scalp (less itching, reduced dandruff)
- Light baby hair: 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 are feeling:
Your hair will feel more "alive" and less dull. You may still be losing as much hair (the telogen cycle is ongoing), but the new hairs that grow in will be stronger.
After 3 Months
What's happening:
- New hairs (anagen phase) grow with a strengthened structure thanks to proteins, vitamins and minerals
- The rate of hair loss decreases (hairs in the telogen phase fall out less quickly)
- Blood circulation in the scalp is improved (regular massages)
Visible results:
- Accelerated growth: +4 to 6 cm in total (compared to 3-4.5 cm normally)
- Visibly improved density: Thicker baby hairs, fewer sparse areas
- Significantly stronger hair: More resistant to manipulation
- 30-50% reduction in hair loss: You lose significantly less hair in the shower and when brushing.
- Optimal shine and softness: Transformed texture
- Stronger nails (bonus collagen): Indicator that collagen is working
What you are feeling:
Your friends and family are starting to notice: "Your hair has grown so fast!" or "It's more beautiful!" You're motivated to continue.
The critical point: Many give up before 3 months. It's precisely from this point onward that the results explode!
After 6 Months and More
What's happening:
- Maximum 3 complete hair cycles: Hairs that were in the telogen (shedding) phase on day 0 were replaced by new, strong hairs
- The anagen phase is prolonged (extended lifespan)
- The hair follicles are functioning at their optimal capacity
Visible results:
- Total growth: +9 to 12 cm (compared to 6-9 cm normally) = +30-50% vs natural rate
- Significantly increased length: Dramatic difference, especially on short/medium-length hair
- Maximum density: Thicker hair, increased volume, fewer thin areas
- Exceptional quality: Top-notch shine, elasticity, and resistance
- Stabilized hair loss: Normal daily loss (50-80 hairs/day max)
- Regrowth on weakened areas: Temples, center part filled in
What you are feeling:
Visible and lasting transformation. You have reached your length goals or are well on your way. The routine has become automatic.
After 6 months:
Continue taking supplements (collagen, vitamins) for maintenance: Take continuously, do not do a course of treatment.
Maintain the care: Healthy scalp, heat protection, balanced routine
Lasting results: As long as you maintain your good habits
FAQ: Your Questions About Hair Growth
Trimming 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 the same (approximately 1 cm/month).
Should we still cut it?
Yes, but only to remove split ends which, if left untrimmed, will travel up the hair shaft 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 as this further stimulates the sebaceous glands)
Curly/kinky hair: Once a week is enough (this hair type is naturally drier)
Sensitive scalp: a maximum of twice a week with an ultra-mild shampoo
Tip : If your hair gets greasy quickly, it's often because you wash it too often. Gradually space out your 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: thoroughly moisturize your ends with an oil or a nourishing mask (avoiding the roots), and you'll see that your roots get greasy less quickly. A balanced scalp = hydrated ends!
How long should you take dietary supplements for?
Short answer: CONTINUOUSLY, not as a treatment.
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 state and hair growth slows down.