You may have already tried a nourishing shampoo without results, or a volumizing mask that weighed down your locks. The problem isn't necessarily your hair, but the treatment you chose.
Identifying your hair type helps you better target your needs and adopt the right habits. In this guide, we help you observe, understand, and adjust your routine for healthier, more beautiful hair, day after day.
Observe the natural shape of your hair
The shape of your hair is the first and easiest step in diagnosis. It depends on the shape of the hair follicle (the root under the skin). The rounder it is, the smoother the hair; the more oval or flattened it is, the more curly or frizzy it will be.
How to take the test?
- Wash your hair with a mild shampoo, without conditioner or styling product.
- Let them air dry without handling them.
- Look at the general shape: straight? wavy? curly? very curly?
Type 1: Straight hair
Always straight from root to tip, they reflect light well, giving them a natural shine.
- 1A : very fine and ultra-straight, fall without volume.
- 1B : still straight but a little thicker, with discreet volume.
- 1C : Straight, thick, slightly prone to frizz.
Type 2: Wavy hair
Shaped like a more or less wide “S”, they offer a nice balance between softness and movement, but can be prone to frizz.
- 2A : Light, soft waves, easy to straighten or curl.
- 2B : more defined waves, moderate frizz.
- 2C : Wide waves with loose curls on the ends.
Type 3: Curly hair
Defined and full of bounce, they can lack hydration because sebum has difficulty reaching the ends.
- 3A : large, soft curls.
- 3B : tight, elastic curls with generous volume.
- 3C : very tight, almost corkscrew curls.
Type 4: Curly to frizzy hair
Very tight and dense, they shrink a lot when dry (up to 70% of their actual length).
- 4A : small regular spirals.
- 4B : “Z” shaped curls with little definition.
- 4C : Very tight texture, with almost no natural definition.
Identify thickness and texture
Thickness is not the overall volume of your hair, but the diameter of a single hair. It's an essential criterion for understanding how your hair reacts to products and styling tools.
How to take the test at home?
Technique 1
- Wash and dry your hair naturally.
- Take a single hair and place it between your thumb and index finger.
- Slide it gently:
- If you barely feel it → it's fine.
- If you feel it clearly → it is thick.
- In between → it is of medium texture.
Technique 2
Compare the thickness of your hair to a sewing thread.
- Thinner than a thread → fine hair.
- Same height → medium hair.
- Thicker than a thread → thick hair.
Fine hair
- Delicate feel, almost invisible to the touch.
- Easy to style, but quickly become heavy with rich products.
- Tendency to break under tension (elastic bands, rough brushing).
Medium hair
- Easy to style.
- Holds hairstyles well.
- Good resistance, responds well to care and heating tools.
Thick hair
- Firm touch, high resistance.
- Need more time to dry and smooth.
- Holds up well to styling, but can become dry if not properly moisturized.
Know the nature: dry, normal or oily
Your scalp produces sebum, a natural oil that protects and nourishes your hair. Depending on the amount produced, your hair will be classified into three categories.
Dry hair
- Lack of shine, rough feel and split ends.
- Quick air drying.
Normal hair
- Flexible, shiny, few particular problems.
- Perfect balance between hydration and nutrition.
Oily hair
- Heavy roots, which quickly regrease.
- Loss of volume from the second day.
What if your roots are oily but your ends are dry ? You have combination hair! The trick is to wash with a purifying shampoo only on the scalp and apply a nourishing treatment only to the lengths.
Test your hair porosity
Porosity is your hair's ability to absorb and retain moisture. It depends on the condition of the cuticles, the tiny scales that cover the fiber.
Glass of Water Test
- Take a clean, dry hair.
- Place it in a glass of room temperature water.
- Wait 2-3 minutes:
-
- It floats → low porosity.
- It flows slowly → medium porosity.
- It flows quickly → high porosity.
Low porosity
- Well-closed cuticles, water and care products penetrate with difficulty.
- Hair takes a long time to dry.
Medium porosity
- Perfect balance: absorbs and retains moisture well.
- Easy to maintain.
High porosity
- Very open cuticles, hair that absorbs quickly but loses moisture quickly.
- Often linked to chemical treatments or excessive heat.
Adapt your routine according to your hair profile
Now that you know your hair type , it's time to develop a routine that works for you. The secret? Choose products that specifically meet your needs... and resist the temptation to buy "what works for everyone."
Routine for straight hair
- Washing : every 2 to 3 days with a light shampoo.
- Care : Conditioner only on the ends.
- Finishing : a small amount of hair serum for shine.
- Tip : Brush morning and evening to distribute sebum and avoid oily roots.
Routine for wavy hair
- Washing : moisturizing shampoos to limit frizz.
- Care : Light styling cream to define waves.
- Finishing : anti-frizz product before drying.
- Tip : Dry at low temperature to avoid stretching the shape.
Routine for curly hair
- Washing : gentle, sulfate-free shampoos.
- Care : moisturizing mask like the moisturizing hair mask once a week.
- Finish : Diffuse or air dry to maintain shape.
- Tip : Apply your products to wet hair to create beautiful curls.
Routine for curly or frizzy hair
- Washing : space out to once a week.
- Care : oil baths before shampooing, nourishing masks.
- Finish : Protective styling and hair oil to seal in moisture.
- Tip : Use the LOC (liquid, oil, cream) method to lock in moisture longer.
Common mistakes to avoid
If you want to take care of your hair, avoid:
- Using products unsuitable for your texture : an ultra-rich mask on fine hair = guaranteed greasy effect.
- Using multiple treatments that don't go together : mixing products with opposing effects can cancel out their benefits.
- Washing too often : especially on dry or curly hair, this removes the natural protective oils.
- Neglect the scalp : a hair scrub once a month helps to cleanse and stimulate growth.
- Using too much heat : Excessive brushing or straightening makes the fiber more fragile and increases porosity.
When should you redo your hair diagnosis?
Your hair doesn't stay the same throughout your life. Certain events can change its nature:
- The seasons: humidity, cold or intense sun.
- Hormones: pregnancy, menopause, hormonal fluctuations.
- Chemical treatments: coloring, bleaching, straightening.
- Health: medical treatments, nutritional deficiencies.
- Stress: which can influence sebum production and density.
Tip : Repeat a diagnosis at home or at the hairdresser every 6 months to adapt your routine to the actual condition of your hair.
Knowing and understanding your hair type is the key to finally seeing real results. By observing its shape, testing its thickness, identifying its nature and porosity, you can set up a routine that suits it perfectly.
FAQ about hair types
Should you adapt your hair routine according to the seasons?
Yes, because the climate directly impacts your hair. In winter, the cold and heat can dry it out. In summer, the sun, salt, or chlorine can weaken it. Adapting your routine allows you to better meet your hair's specific needs at each time of year.
How do I know if my hair is fine, medium or thick?
Take a hair between your fingers: if it is barely perceptible, it is fine; if it is clearly felt but not rigid, it is medium; if it is thick and solid to the touch, it is considered thick. This distinction helps you choose care products that are suited to the structure of your hair fiber.
Why is it important to know your hair porosity?
Porosity determines hair's ability to absorb and retain moisture. Highly porous hair requires richer treatments to retain water; low-porosity hair requires lighter textures. Adapting your routine to your porosity improves the effectiveness of your treatments.
How to identify your hair type?
To determine your hair type, look at its texture (straight, wavy, curly, frizzy), its density (thick or thin), and its porosity (its ability to absorb water). Feel your hair after washing: if it dries quickly, it's often porous; if it stays wet for a long time, it's not very porous.
How do I know if my hair care products are right for my hair?
Observe the result after application: hair weighed down, dull, or difficult to style? The treatment is probably too rich or not moisturizing enough. Fine hair prefers lighter textures, while thick hair needs more nourishing formulas.
