LAIA SALLAN TREPAT
Special Chemicals, Barcelona, Spain

Hair and scalp care is a vital aspect of beauty and health routines for many people around the world. With advancements in cosmetic science, we have witnessed a significant evolution in the techniques and products used to maintain hair health. One of the latest innovations in this field is hair skinification, an approach that applies skincare principles to the scalp and hair, which has become a trend.

Hair skinification is based on the idea that the scalp, like facial skin, requires specific and personalized attention. By applying this approach, companies developing hair care products aim not only to improve the appearance of the hair but also to address underlying scalp issues such as dryness, itching, dandruff, or inflammation (1,2).

In today’s hair cosmetic industry, there is a growing demand for effective yet affordable products. Consumers are increasingly informed about ingredients and seek products that deliver proven results. In this context, multifunctional ingredients play a crucial role by adding value to hair products without compromising quality or significantly increasing costs.

A core aspect of hair skinification is the use of multifunctional ingredients in cosmetic products, as one ingredient can be designed to address multiple needs of the scalp and hair, providing benefits beyond mere aesthetics (Figure 1).

Multifunctional ingredients offer a broad range of benefits for hair and scalp, allowing manufacturers to develop more comprehensive and effective products without drastically increasing prices. In the information era, consumers are more educated and demanding about the efficacy of the products they choose. They no longer settle for empty marketing promises but seek scientific evidence to back up product claims.

Here are some examples of multifunctional ingredients and their benefits in hair skinification:

Peptides

Peptides are chains of aminoacids that can penetrate the skin and hair, stimulating the production of collagen and elastin. In hair skinification, peptides help strengthen hair from the root, promoting healthier and more resilient growth. For example, Copper Tripeptide-1 (GHK-Cu) has been shown to significantly increase vascular endothelial growth factor (VEGF) expression, which is associated with improved perifollicular vascularization and follicle size, while decreasing TGF-β1 expression, indicating reduced apoptosis, thus promoting hair growth and reducing hair loss (3).

Another example is Tripeptide-10 citrulline, which enhances the quality of dermal collagen in the hair follicle, strengthening hair structure from the root. This helps prevent premature hair loss and promotes healthier, more vigorous growth (4).

Apigenin

Apigenin is a flavonoid found in various plants, such as celery (Apium graveolens) and chamomile (Chamomilla recutita), offering a range of benefits for hair. Besides its antioxidant properties, apigenin acts as a hair conditioner, making hair more manageable, flexible, soft, and shiny. It is also associated with lowering dihydrotestosterone (DHT) levels, a hormone linked to hair loss. By competing with the binding site of DHT, apigenin inhibits the activity of the enzyme 5-α reductase, reducing DHT levels in the scalp and potentially preventing hair loss and promoting healthier growth (5).

Centella asiatica extract

Centella asiatica (Centella asiatica) has been used for centuries in traditional Asian medicine due to its notable therapeutic properties and has recently found its place in cosmetic formulations for skin care. For the scalp, it emerges as a key ingredient due to its ability to soothe irritation and restore skin balance, in addition to its anti-inflammatory and healing properties. Studies have shown that Centella asiatica improves the capacity of dermal papilla cells to stimulate hair growth by increasing the expression of related genes (6).

Jojoba oil

Jojoba oil is a valuable resource in hair cosmetics due to its abundance of nutrients and antioxidants. This versatile ingredient not only moisturizes the scalp but also balances sebum production, making it an ideal choice for hair care products. Additionally, its ability to strengthen hair from root to tip makes it an indispensable ally for those seeking to improve the health and appearance of their hair (7).

These are just a few examples of multifunctional ingredients that can be used in hair skinification. Combining these ingredients in specialized cosmetic products can provide a comprehensive solution for scalp and hair care.

In addition to using multifunctional ingredients, hair skinification also focuses on identifying and addressing specific therapeutic targets in the scalp. There is extensive evidence from studies comparing hair from individuals with dandruff and seborrheic dermatitis, atopic dermatitis, and psoriasis with hair from a control group with healthy scalps, clearly showing the relationship between these conditions and their impacts on hair (Table 1).

Some examples of targets and potential treatment approaches in hair skinification include:

Scalp inflammation

Chronic scalp inflammation can be challenging and is often linked to dermatological conditions like seborrheic dermatitis and alopecia areata. These conditions can cause physical discomfort such as itching and sensitivity, and also significantly impact the health and appearance of hair.

In hair skinification, addressing scalp inflammation with specific care that helps soothe and control irritation is crucial. Effective approaches include using anti-inflammatory ingredients with calming and reparative properties, such as calendula extract or bisabolol or the aforementioned centella asiatica extract.

Skin microbiota control

The scalp microbiota plays a crucial role in its health and balance. Maintaining a healthy microbiome is essential to prevent issues like dandruff or itching. In hair skinification, prebiotic ingredients can be used to nourish beneficial bacteria on the skin, or probiotics can be used to colonize the skin and compete with pathogenic bacteria, promoting a healthy microbiome and reducing the incidence of these issues.

Prebiotic ingredients such as oatmeal extracts, honey, or hyaluronic acid provide nutrients that support the growth of beneficial bacteria, helping to strengthen the skin barrier. Probiotics, such as Lactobacillus and Bifidobacteria, are good candidates for inclusion in specific scalp care formulations, reducing the proliferation of harmful bacteria and promoting a healthy scalp environment (9).

Hair growth stimulation

Encouraging hair growth is a fundamental goal in treating hair loss. Ingredients like ginseng and caffeine not only stimulate blood circulation but also nourish hair follicles, strengthening hair growth from the root.

Ginseng is known for its stimulating and revitalizing properties. When applied topically to the scalp, ginseng extract can improve blood circulation by dilating blood vessels, increasing nutrient and oxygen flow to hair follicles. Its active components, ginsenosides, stimulate the growth phase and delay the regression phase of hair, creating a favorable environment for new, healthy hair growth (10).

Caffeine has also proven beneficial for hair health as it effectively penetrates hair follicles. In vivo studies in individuals with androgenetic alopecia (AGA) show that topical formulations with caffeine reduce hair loss, demonstrating comparable effectiveness to minoxidil in men with AGA (11).

Well-being and comfort

In hair skinification, the goal is not only to address specific scalp and hair concerns but also to enhance user well-being and comfort during their hair care routine. This perspective recognizes the importance of creating a sensory and emotionally gratifying experience. Hair skinification products often incorporate ingredients known for their relaxing and soothing properties, and also product textures and formulations play a crucial role in user experience. Additionally, in salon treatments, dedicated massage techniques for certain masks can draw an interesting parallel to body or face massages. These scalp massages not only stimulate blood circulation but also further promote a sense of well-being, making the entire treatment more holistic and rejuvenating.

Hair skinification has opened new possibilities in the cosmetic industry, driving the search for innovative solutions for scalp and hair care. This section explores some promising ideas and techniques that can be applied in cosmetic products for this purpose.

Specialized botanical extracts

Botanical extracts have traditionally been used in herbal medicine to treat various skin and hair conditions. In hair skinification, cosmetic products can be developed combining specialized botanical extracts selected for their specific properties for scalp and hair care. For example, a combination of lavender, calendula, and chamomile extracts can help reduce scalp inflammation while promoting hair growth.

Hair microneedling

Microneedling is a technique that uses fine needles to create micro-injuries in the skin, stimulating collagen production and improving the absorption of topical treatments. In hair skinification, microneedling can be combined with specialized serums containing growth factors or peptides to enhance their effectiveness in stimulating hair growth and improving overall scalp health (12). Many users and publications, report the synergetic effect of combining microneedling with topical treatments such as minoxidil. However, caution is advised. Due to the scalp's high density of follicles, it has a greater capacity to absorb ingredients compared to facial skin, which raises concerns about the potential for a larger amount of ingredients entering the bloodstream. Misuse of microneedling can further increase these risks, making it essential to follow proper guidelines and consult with professionals before incorporating this method into a routine.

Encapsulation of active ingredients

Encapsulation is a widely used technique for the controlled delivery of nutrients and active ingredients to the skin and hair. While liposomes have a long history of use in cosmetics due to their ability to enhance ingredient stability and penetration, other technologies, such as polycaprolactone (PCL) and alginate, have been extensively utilized in medical applications and have gained increasing popularity in cosmetics over the years. In hair skinification, these advanced encapsulation systems (Figure 2) protect sensitive ingredients and improve their targeted delivery into the scalp and hair follicle, optimizing the effectiveness of active ingredients for scalp health and hair growth.