Why use a hair growth serum to stimulate hair growth?

• Activates microcirculation in the scalp to nourish the hair bulb and prolong the growth phase.
• Provides targeted active ingredients (rosemary oil, pea shoot extract, biotin) that strengthen the hair fiber and promote regrowth.
• Reduces hair loss by improving the anchorage and strength of the hair fiber.
• Hydrates and protects the scalp with formulas enriched with natural ingredients and leave-in care.
• Optimizes hair density and thickness over time, especially when used as part of a complete three-month treatment.

What is a hair growth serum and what is it used for?

Definition and role of a hair serum

A hair growth serum is a lightweight formula with a high concentration of active ingredients, designed to act directly on the scalp and hair follicles. Its fluid texture allows it to penetrate quickly without weighing down or greasing the hair.

Unlike hair oil, which mainly nourishes the lengths, or lotion, which is often more watery and superficial, serum is designed to target hair growth at the root.

The benefits of a growth serum on hair growth

An effective serum acts simultaneously on several essential mechanisms:

• Improved microcirculation in the scalp, promoting the supply of oxygen and nutrients to the follicles.
• Strengthens hair fibers, reducing breakage and maintaining density.
• Stimulation of the bulb to prolong the active growth phase, thereby supporting faster and more consistent growth.

Difference between hair growth and regrowth

Growth refers to the continuous lengthening of an existing hair, while regrowth refers to the return to activity of a follicle that has been inactive.

A good hair growth serum addresses both situations: it accelerates the growth of existing hair and promotes the emergence of new hair.

How does a hair growth serum work?

Key ingredients that stimulate hair growth

The best serums combine several active ingredients known for their effects on growth:

• Rosemary oil: stimulates local blood circulation and supports follicle activity.
• Castor oil: rich in fatty acids, it deeply nourishes and strengthens the hair fiber.
• Pea shoot extract: stimulates cellular activity in the bulb.
• Biotin, vitamin B5, and zinc: essential elements for keratin synthesis and maintaining strong hair.
• Organic plants such as horsetail, arugula, and green tea: sources of antioxidants that protect the scalp and soothe sensitivity.

Anti-hair loss and thickening action of the serum for hair growth

Thanks to their concentrated formula, these treatments slow down reactive or progressive hair loss while improving the visual and tactile density of the hair. The goal is not only to stimulate growth, but also to preserve and strengthen what is already there.

The visible evidence and results of a good serum for hair growth

The effects of a hair growth serum are not immediate: the hair cycle requires patience and consistency. A three-month course of daily application generally results in reduced hair loss, thicker hair, and increased density in thinning areas.

How to apply a hair growth serum? Our nighttime routine Madame d'Alexis

How to choose the right hair growth serum?

The essential criteria for an effective product

To select a truly effective hair growth serum, focus on four key factors:

• Natural origin – a formula based on plants or gentle active ingredients improves tolerance, particularly on sensitive scalps.
• Concentration of active ingredients – choose formulas enriched with targeted, undiluted ingredients.
• Light texture – a fluid, non-greasy serum that absorbs rather than leaving a film.
• Leave-in treatment – to ensure long-lasting effectiveness, allow the active ingredients to work continuously.

Organic, natural, or conventional serum: which one should you choose for hair growth?

Plant-based formulas, particularly those made in France, often offer the best compromise between skin-friendliness and performance. Free from silicone and unnecessary fragrances, they respect the hair fiber while preserving its natural shine and density.

Price and value for money

To evaluate the value of a serum, compare:

• the concentration of active ingredients (e.g., pea shoot extract or peptides);
• the announced clinical results (increased density, reduced hair loss);
• price positioning relative to benchmarks such as Luxéol or high-end organic brands.

A more expensive formula can be truly beneficial if it guarantees proven effectiveness, which is essential for a "care" investment.

Application and routine: how to use a serum for hair growth?

Technique for applying serum to stimulate growth

The technique is essential. Apply the serum directly to the scalp, then massage in with light circular movements using your fingertips. This stimulation boosts microcirculation and helps the active ingredients to be absorbed.

Integrate serum into a complete hair routine

Incorporating the serum into your daily routine creates a beneficial synergy:

• start with a mild shampoo suitable for your scalp;
• add a nourishing mask to the lengths;
• If necessary, supplement with a targeted dietary supplement to support growth from within.

Duration and frequency of use of a serum to stimulate hair growth

Patience is your best ally. A treatment lasting at least three months, applied daily or twice daily, exposes the target follicles to the active ingredient sufficiently. It is often after this point that we see improved density, reduced breakage, and, in some cases, the return of stubborn regrowth.

Top 5 best hair growth serums in 2025

Madame d'Alexis Repairing and Revitalizing Night Serum

Madame d'Alexis's repairing and revitalizing night serum stands out thanks to its innovative formula, designed without added water and made exclusively from certified organic hydrosols. This unique feature increases the concentration of active ingredients and guarantees maximum effectiveness while respecting the physiology of the scalp.

Its composition combines three precious floral waters:

• Damask rose hydrosol: restores moisture, smooths the hair fiber, and soothes irritation thanks to its natural anti-inflammatory properties.
• Chamomile hydrosol: soothes skin sensitivities and enhances the hair's natural shine.
• Orange blossom hydrosol: revitalizes tired hair, stimulates cell regeneration, and tones the roots.

Enriched with cationic hyaluronic acid, this treatment intensely nourishes, repairs weakened areas, and adds volume from the root. The probiotics it contains help balance the scalp's microbiome, which is essential for limiting inflammation and supporting healthy growth.

Finally, a complexof botanical extracts that prevent hair loss (oak bark, nettle, licorice) acts as a structural reinforcement, strengthening the follicle and limiting loss.

Applying the product at night and massaging it directly into the scalp maximizes the penetration of active ingredients during cell regeneration phases. Upon waking, hair is visibly more supple, dense, and radiant.

Other market references

For a complete overview, other serums are also popular in 2025:

• Concentrated rosemary oil serum: valued for its ability to stimulate microcirculation and combat progressive hair loss.
• Serum with pea shoot extract: directly stimulates cellular activity at the bulb and strengthens the anagen phase.
• Biotin and zinc serum: combines two nutrients essential for keratin synthesis, optimizing hair strength and elasticity.
• Horsetail and green tea serum: rich in antioxidants, it protects the hair fiber from oxidative stress and maintains an environment conducive to growth.

These alternatives may meet specific needs, such as sensitive scalps, reactive hair loss, or the desire for immediate thickening effects, but few combine the sensory richness, formulation standards, and concentration of active ingredients found in Madame d'Alexis night serum.

Hair growth and density ritual: the two-step method

Why this ritual stimulates growth and thickens hair

Thinning hair and slower growth are often caused by a congested scalp, insufficient microcirculation, and an unbalanced microbiome.

Thishair growth and density ritual acts on three fronts: it purifies, stimulates, and nourishes to recreate an environment conducive to follicle health. The result: better oxygenated roots, strengthened bulbs, and revitalized hair growth.

The benefits, step by step, of the growth and density ritual

• Scrub – detoxification and oxygenation
  Removes impurities, excess sebum, and styling product residue. Fleur de sel and organic hydrosols gently exfoliate, activate microcirculation, and prepare the scalp to receive the serum's active ingredients.
• Night serum – stimulation and reinforcement
  Works while you sleep to strengthen roots and activate hair growth. Probiotics rebalance the microbiome, whilecationic hyaluronic acid hydrates without weighing hair down and improves skin comfort.

Expected results and observation period

With daily application of the serum and weekly exfoliation, most users notice the following results over the course of a 3-month treatment:

• renewed growth and visibly improved density;
• a purified and oxygenated scalp;
• reinforced bulbs and optimized anchoring;
• Thicker, stronger, healthier-looking hair.

Recommended usage

• Once a week: apply the scrub to damp scalp, massage in circular motions, rinse thoroughly.
• Every evening: apply the Night Serum strand by strand, massage the scalp for 1 minute to boost microcirculation, leave on without rinsing.
• Routine tip: combine a gentle shampoo with a light moisturizing mask to keep your scalp comfortable and your hair supple.

Frequently asked questions about hair growth serum

Does the serum really make hair grow?

A hair growth serum acts as a growth activator by creating an optimal environment for hair growth. It stimulates microcirculation in the scalp, delivers nutrients directly to the hair bulb, and prolongs the anagen phase.

This processstimulates growth and strengthens existing hair. Results depend on the quality of the active ingredients and regularity of application, generally as part of a complete treatment program.

Which serum is most effective for rapid hair growth?

The most effective serum is one that combines several modes of action: stimulating blood circulation, providing essential nutrients, and protecting the scalp against oxidation and inflammation.

Formulas containing rosemary oil, pea shoot extract, B vitamins (biotin, B5), zinc, and antioxidant plants such as horsetail and green tea are particularly well known. 

Skincare products without added water, which are more concentrated in active ingredients, are often more effective, provided they are applied correctly and continuously.

Is a dietary supplement necessary in addition to the serum?

Combining a dietary supplement for hair with a topical serum maximizes results. The serum acts externally on the scalp and follicles, while the supplements provide the amino acids, vitamins, and minerals necessary for keratin production from within.

This dual approach is particularly recommended in cases of seasonal hair loss, deficiencies, or after periods of stress, when hair health is compromised.

Can the serum be used on curly, fine, or oily hair?

Yes, provided you choose the right texture. Water-based or light serums are suitable for fine or oily hair because they penetrate without weighing it down or making it greasy.

Curly hair, which is often drier, particularly benefits from formulas enriched with moisturizing agents such as hyaluronic acid or vegetable glycerin. 

In all cases, the product should be applied to the scalp rather than the lengths of the hair to avoid overloading.

How often should you apply a hair growth serum?

Most formulas require daily application or at least three to four times a week.

Consistency is key, as the hair cycle follows a slow rhythm. Visible results are generally observed after 8 to 12 weeks of continuous use.

Can hair growth serum be used all year round?

Yes. Unlike seasonal treatments, a gentle, well-formulated serum can be applied continuously, particularly to maintain the results achieved and prevent further hair loss.

However, some users choose to intensify the application in spring and fall, periods when hair loss is physiologically greater.

How can I stimulate hair growth?

To stimulate growth, combine targeted local care such as a hair growth serum with a healthy lifestyle and appropriate nutritional intake.

Ingredients to look for includerosemary oil, plantshoot extract, and vitamin complexes that promote hair growth.

Acomplete treatment lasting several months maximizes the effects and promotes lasting results.

What are the best hair serums?

The best hair care products are those that combine highly concentrated active ingredients with a formula that is gentle on the scalp.

Thebest hair growth serum combines several functions: stimulating hair serum, growth serum, anti-hair loss serum, and thickening serum. It should also be considered a complete hair care product, acting on both the hair fiber and the bulb.

How can hair loss be reduced?

To reduce hair loss, it is essential to address its causes: hormonal imbalance, oxidative stress, or deficiencies. A good anti-hair loss serum acts to maintain hair and promotes its anchoring in the scalp.

Used asa complete treatment, it supports hair in the growth phase and prevents further hair loss.

Which ingredients promote hair growth?

The most recognized natural ingredients include:castor oil to strengthen,pea shoot extract to activate the bulb, organic plants to protect, and biotin combined with vitamins to stimulate keratin production.

Natural ingredients work together to accelerate growth and improve density.

How long does a serum last?

A period of 3 months is generally recommended to see lasting effects. The first month prepares the scalp, while the following months optimize the complete treatment.

Daily application andregular use are essential to achieve full effectiveness and obtain visible results.

How to apply hair serum?

To apply the serum, place it directly on the scalp, then massage the scalp using circular movements. This application technique activates microcirculation and promotes the penetration of active ingredients.

In leave-in treatment, it fits perfectly into an overall hair care routine, following the manufacturer's instructions for use.

What are the effects of a hair serum?

A high-performance hair serum stimulates growth, strengthens the hair fiber, repairs and thickens weakened areas, nourishes and fortifies the root, and gives the hair strength and shine.

Regular usereduces hair loss and improves hair density over the long term.