Hair care is not only about the appearance of the hair fiber. The scalp is a living environment shaped by sebum, barrier function, immune responses and the microorganisms that live on it. The recent “skinification of hair” approach reflects this by treating the scalp as a distinct part of the care routine. However, when discussing the microbiome, pH or hair follicles, marketing language needs to be separated from biological evidence.
What Is the Scalp Microbiome?
The scalp is not sterile. Communities of fungi and bacteria live on its surface and around hair follicles. Malassezia species, Cutibacterium and Staphylococcus can be natural members of the scalp ecosystem.
Research also suggests that hair follicles can form a distinct microbial habitat. However, how these microorganisms directly affect hair growth or hair shedding is still not fully understood. Claims such as “balancing the microbiome grows hair” or “a disrupted follicular microbiome causes hair loss” go beyond the current evidence.
Malassezia and Dandruff Appearance
Malassezia is a group of lipophilic yeasts that can also be found on healthy scalp. It can use lipids in sebum, and free fatty acids may be produced during this metabolism. Malassezia is an important factor in dandruff and seborrheic dermatitis research, but current science does not explain dandruff simply as “too much Malassezia.”
Microbial composition, sebum and sebum metabolites, scalp barrier function, inflammatory responses and individual susceptibility may all contribute to visible dandruff. The same microorganism can therefore be well tolerated by one person while being associated with symptoms in another depending on barrier and immune responses.
Why Do the Barrier, Sebum and Inflammation Matter?
The outer scalp layer acts as a barrier that limits water loss and helps protect against environmental factors. Sebum is also a natural part of this surface environment. The goal is not to eliminate sebum completely, but to remove excess oil, sweat, product residue and shed cells with cleansing suited to the scalp’s needs.
Persistent redness, itching, marked flaking or inflammation should not be reduced to a cosmetic “clogging” problem. Hair follicles are not pores that “breathe”; product or sebum buildup does not deprive a follicle of oxygen and cut off its nutrition. “Letting the follicle breathe” is a marketing metaphor, not a biological mechanism.
Does the Scalp Need a pH of Exactly 5.5?
pH is one parameter considered in shampoo formulation. Highly alkaline conditions can negatively affect some surface properties and friction of the hair fiber. However, scientific literature does not establish one universal “ideal pH 5.5” for every scalp and every shampoo.
It is therefore not accurate to infer that a product protects the scalp microbiome from pH alone. The complete formula, surfactant system and concentrations, contact time, other ingredients and the individual characteristics of the scalp all matter.
Is Sulfate-Free Shampoo Automatically “Microbiome-Friendly”?
No. SLS and SLES are effective surfactants used in cosmetics. Their presence alone does not prove that a shampoo makes the scalp alkaline, damages the microbiome or promotes harmful microorganisms.
SLS/SLES-free shampoos can offer a different cleansing and sensory profile. Mirissa Lab shampoo does not contain SLS or SLES, but this should not be interpreted as a guarantee that it “rebalances the microbiome.” Shampoo suitability depends on the complete formula and individual needs.
What Does “Scalp Detox” Really Mean?
“Detox” is commonly used in cosmetic communication, but it does not describe a special toxin-removal mechanism of the scalp. In practical scalp cleansing, the real goal is to remove excess sebum, sweat, environmental particles and product residue with an appropriate cleansing system.
Exfoliating acids such as AHA or BHA may be used in some specialized scalp products, but not every scalp needs chemical exfoliation. Adding acidic exfoliants without understanding the cause of flaking, redness or sensitivity is not automatically a better routine.
The Mirissa Lab Formulation Approach
Mirissa Lab approaches scalp care through a routine that combines cleansing, oil-balance focused care, moisture, comfort and complementary care rather than relying on a single “miracle active.”
Shampoo: Cleansing and Scalp Comfort
The current formula of Mirissa Lab Sulfate-Free Salt-Free Scalp Shampoo includes:
- Zinc PCA, used in scalp care to support a balanced-looking oil/sebum profile.
- Lactobacillus Ferment Lysate + Inulin, complementary ingredients in a microbiome-focused scalp-care approach. This does not mean that the finished product has been clinically shown to “rebalance” the microbiome.
- Panthenol, Betaine, Bisabolol and Aloe Vera, which support a moisturized, comfortable and cared-for scalp feel.
- Hydrolyzed Wheat Protein, which contributes to a stronger, more cared-for feel in the hair fibers.
The formula does not contain SLS or SLES, and Sodium Chloride is not present in the current INCI list.
Serum: Nighttime Scalp Care
The current formula of Mirissa Lab Scalp Serum includes Niacinamide, Zinc PCA, Panthenol, Squalane, Allantoin and peptides such as Biotinoyl Tripeptide-1 and Acetyl Tetrapeptide-3.
These ingredients are positioned within a routine that supports scalp care, moisture and comfort, and a stronger, fuller and more cared-for appearance for hair prone to shedding. The serum also contains Rosmarinus Officinalis Extract; however, it is not scientifically valid to take studies using rosemary oil in different forms and concentrations and claim that a cosmetic formula containing rosemary extract is “as effective as minoxidil” or “free of side effects.”
For a routine combining both steps, explore the Mirissa Lab Scalp Care Set.
When Should You See a Dermatologist?
Cosmetic care can support everyday scalp comfort and appearance, but persistent heavy flaking, marked redness, severe itching, sores, crusting, pain or sudden and patchy hair loss should be evaluated by a dermatologist.
Conclusion
The scalp microbiome is a real and still-evolving area of scalp biology research. But current evidence does not support presenting the microbiome as the sole cause of dandruff or hair loss, declaring pH 5.5 a universal solution, claiming that a “clogged follicle cannot breathe,” or inferring hair growth from a single botanical extract.
A more accurate approach is to treat the scalp as an ecosystem and focus on the complete formula: appropriate cleansing, barrier and comfort support, oil-balance focused care and complementary steps when needed.
Scientific References
- Scalp microbiome: a guide to better understanding scalp diseases and treatments. 2024. PMID: 39073596.
- Dandruff severity is associated with changes in the scalp microbiome. Br J Dermatol. 2025. PMID: 41118316.
- Spatial Distribution and Functional Impact of Human Scalp Hair Follicle Microbiota. J Invest Dermatol. 2024. PMID: 38070726.
- More yeast, more problems?: reevaluating the role of Malassezia in seborrheic dermatitis. 2024. PMID: 38472524.
- The Shampoo pH can Affect the Hair: Myth or Reality? Int J Trichology. PMID: 25210332.
- Seborrheic dermatitis and dandruff: An overview of pathogenesis, role of Malassezia spp. and current treatment approaches. 2026. PMID: 41616707.
This content is for informational purposes. Mirissa Lab products are cosmetic care products and do not replace medical diagnosis or treatment.
