Scalp and Face: The Same Microbiome Most People Forget

The scalp is the most neglected extension of skincare. It shares the same basic biology as facial skin — microbiome, sebaceous glands, skin barrier — with one particularity: hair follicle density that creates a different microenvironment more susceptible to imbalances. Scalp problems (excessive oiliness, dandruff, seborrhoea, irritation) rarely have to do with the shampoo. They have to do with microbiome balance.

Dandruff Is Not Dry Skin

It's one of the most persistent misconceptions. Dandruff is mainly caused by Malassezia globosa — a fungus that naturally exists on everyone's scalp but that, in imbalance, metabolises sebaceous lipids into oleic acid that irritates the skin and triggers accelerated flaking. Treating dandruff with moisturising shampoos (for dry skin) doesn't solve it — and may worsen it by feeding the fungus.

Scalp Health Principles

• Correct pH: shampoos with pH 4.5–5.5 preserve the microbiome; alkaline ones (pH 9) disturb it
• No SLS when possible: gentle surfactants are kinder to bacterial flora
• Adapted frequency: washing more frequently doesn't resolve chronic oiliness — it can worsen it through compensatory sebaceous hyperactivity
• Regular massage: stimulates follicular blood circulation; contributes to hair growth

The Connection Between Stress and Hair

Stress raises cortisol, which increases sebaceous sebum production and imbalances the skin microbiome. It's the most common cause of sudden-onset scalp oiliness in adults with no prior history. Microbiome management with prebiotics — both on the face and scalp — is a complementary approach.