EcoProbiotic

Literature

The sources behind our guides

30 sources, 19 of them studies published in peer-reviewed journals. Next to each source you'll see which guide it is used in.

Skin barrier, washing and cleansers

How the skin's outermost layer holds on to moisture, and how hot water, harsh cleansers and frequent washing affect it.

  1. Peer-reviewed studyAnanthapadmanabhan et al., cleansers and skin lipids, 2013

    Used in: What is the skin barrier, and why does it wear down?, Why does your skin itch after a shower?, Does oily skin need moisturizer?, Are you washing your face the right way?, What does pH 5.5 mean, and why does it matter for skin?, What does sulfate-free mean?

  2. Peer-reviewed studyEffect of water temperature on the skin barrier, PMC8778033

    Used in: What is the skin barrier, and why does it wear down?, Why does your skin itch after a shower?, Are you washing your face the right way?, Why does your skin get dry in winter?, Skin care after training

  3. Peer-reviewed studySkin hydration and water loss after bathing, PubMed 33769640

    Used in: What is the skin barrier, and why does it wear down?, Why does your skin itch after a shower?, When and how should you apply moisturizer?

  4. Peer-reviewed studyA shaving model and barrier disruption, PMC10818121

    Used in: What is the skin barrier, and why does it wear down?, Why does your face burn after shaving?, Is men's skin different from women's?

  5. Peer-reviewed studyEffect of a moisturizer on fine lines, 12-week clinical study, JDD

    Used in: What is the skin barrier, and why does it wear down?

  6. Expert body guidanceAmerican Academy of Dermatology, tips for dry skin

    Used in: Why does your skin itch after a shower?, When and how should you apply moisturizer?, Why do your hands get dry when you wash them often?, Why does your skin get dry in winter?

  7. Expert body guidanceAAD, face washing guide

    Used in: Are you washing your face the right way?, When and how should you apply moisturizer?, How to use a clay mask, How can you tell your skin type?, What is sensitive skin, and how do you care for it?

  8. NewsFrequent hand washing and irritant dermatitis

    Used in: Why do your hands get dry when you wash them often?

  9. Peer-reviewed studyPrevalence of hand dermatitis, British Journal of Dermatology

    Used in: Why do your hands get dry when you wash them often?

  10. Peer-reviewed studyLambers et al., skin surface pH is below 5, Int J Cosmet Sci 2006

    Used in: What does pH 5.5 mean, and why does it matter for skin?

  11. Peer-reviewed studySodium lauryl sulfate and the skin barrier, PubMed 18717861

    Used in: What does sulfate-free mean?

Moisturizing, dryness and skin type

When and how to apply moisturizer, dryness in winter and in sensitive skin, and why oily skin still needs moisture.

  1. Peer-reviewed studyRahrovan et al., female and male skin, IJWD 2018

    Used in: Does oily skin need moisturizer?, Why do your roots get greasy so fast?, Is men's skin different from women's?

  2. Peer-reviewed studySebum and pore size, PubMed 17034515

    Used in: Does oily skin need moisturizer?

  3. Peer-reviewed studyClay masks, PMC10626287

    Used in: Does oily skin need moisturizer?, How to use a clay mask

  4. Peer-reviewed studyEffect of indoor winter conditions on the skin, PMC10264749

    Used in: Why does your skin get dry in winter?

  5. Expert body guidanceAAD, skin care tips dermatologists use

    Used in: How can you tell your skin type?

  6. Expert body guidanceAAD, caring for oily skin

    Used in: How can you tell your skin type?

  7. Peer-reviewed studySelf-reported sensitive skin: systematic review and meta-analysis, PubMed 31869523

    Used in: What is sensitive skin, and how do you care for it?

  8. Peer-reviewed studySensitive skin, Frontiers in Medicine 2019

    Used in: What is sensitive skin, and how do you care for it?

Oily skin and clay masks

What a clay mask does for oily skin and how to use it.

  1. NewsStudy on the temporary effect of clay masks, Cosmetics Design 2025

    Used in: How to use a clay mask

Scalp

Itchy scalp, oily roots and how often to wash.

  1. Peer-reviewed studyPunyani et al., shampoo frequency and the scalp, Skin Appendage Disord 2021

    Used in: Why does your scalp itch?, Why do your roots get greasy so fast?

  2. Expert body guidanceAAD, tips for dandruff

    Used in: Why does your scalp itch?, Why do your roots get greasy so fast?

  3. Peer-reviewed studyEpidemiology of sensitive scalp, Karger

    Used in: Why does your scalp itch?

Shaving, sweat and men's skin

How shaving affects the skin, where sweat odor comes from, post-workout care, the skin under the beard and how men's and women's skin differ.

  1. Peer-reviewed studyShaving and barrier damage, Frontiers in Medicine 2023

    Used in: Why does your face burn after shaving?

  2. Expert body guidanceAmerican Academy of Dermatology, shaving tips for men

    Used in: Why does your face burn after shaving?

  3. Peer-reviewed studyMinhas et al., the precursor of underarm odour, eLife 2018

    Used in: What causes sweat odor?

  4. Peer-reviewed studyFresh sweat is odourless, SCC archive

    Used in: What causes sweat odor?

  5. Expert body guidanceAAD, how to sweat without breaking out

    Used in: Skin care after training

  6. Expert body guidanceAAD, tips for a healthy beard

    Used in: Why does the skin under your beard itch?

  7. Expert body guidanceAAD, home care for beard problems

    Used in: Why does the skin under your beard itch?