Study evaluating the effects of a metabolite-based soap on skin hydration and sensitive skin symptoms in healthy adults
| ISRCTN | ISRCTN37934199 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN37934199 |
| Sponsor | Japanese Medical Institute |
| Funder | Japanese Medical Institute |
- Submission date
- 17/03/2026
- Registration date
- 21/05/2026
- Last edited
- 21/05/2026
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Skin and Connective Tissue Diseases
Plain English summary of protocol
Background and study aims
Sensitive skin is commonly associated with dryness, irritation, and reduced skin barrier function. Traditional cleansers may disrupt skin lipids and microbial balance. A new metabolite-based soap containing fermentation-derived postbiotic metabolites has been developed to help support skin barrier health and microbial balance.
This study aims to evaluate whether regular use of this soap improves skin hydration, reduces symptoms of sensitive skin, and improves skin barrier function compared with a neutral control soap.
Who can participate?
Healthy adults aged 20 to 45 years with self-reported sensitive skin and Fitzpatrick skin types II–V
What does the study involve?
Participants will first complete a 2-week washout period using a neutral cleanser. They will then be randomly assigned to one of two sequences to receive either the metabolite-based soap or a control soap. Each soap will be used for 4 weeks, with a 3-week washout period between treatments. Participants will wash their face and forearm twice daily with the assigned soap.
During clinic visits, researchers will measure skin hydration, skin barrier function, sensitive skin symptoms, skin microbiome composition, and biochemical markers related to skin lipids and cellular energy.
What are the possible benefits and risks of participating?
Participants may experience improvements in skin hydration and reduced skin sensitivity. Risks are expected to be minimal and may include mild skin irritation, dryness, or temporary discomfort related to the cleansing products.
Where is the study run from?
Innovation Labo Sciences Co., Ltd (Japan)
When is the study starting and how long is it expected to run for?
October 2025 to February 2026
Who is funding the study?
Japanese Medical Institute
Who is the main contact?
Dr Taro Hirata, coordinate@medica-labs.jp
Contact information
Scientific
Shintomi HJ bldg 5F
1-12-7 Shintomi
Chuo-ku
104-0041
Japan
| Phone | +81 (0)335525335 |
|---|---|
| development@innovationlabo.com |
Public
Shintomi HJ bldg 5F
1-12-7 Shintomi
Chuo-ku
104-0041
Japan
| Phone | +81 (0)335525335 |
|---|---|
| tokyo@innovationlabo.com |
Principal investigator
14-5 Kusunokichō, Nishi-ku
Yokohama-shi
Kanagawa-ken
Yokohama
220-0003
Japan
| Phone | +81 (0)335525335 |
|---|---|
| coordinate@medica-labs.jp |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | Randomized controlled trial |
| Masking | Blinded (masking used) |
| Control | Placebo |
| Assignment | Crossover |
| Purpose | Treatment |
| Scientific title | A randomized double-blind two-sequence two-period crossover clinical trial in healthy adults with sensitive skin comparing a metabolite-based soap with a neutral control soap to evaluate effects on skin hydration, skin barrier function, sensitive skin burden, microbiome composition, lipid profile, and cellular energy markers |
| Study objectives | To determine whether four weeks of use of a metabolite-based soap improves facial skin hydration compared with a neutral control soap in healthy adults with sensitive skin. |
| Ethics approval(s) |
Approved 15/09/2025, Japanese Society of Anti-Aging Nutrition (JAAN) Ethics Review Committee (Ginza, Tokyo 6-6-1, Chuo-ku, 104-0061, Japan; +81 (0)3 3552 5277; coordinator@jaan.jp), ref: JAAN/JMI BTR RCT AP-21 |
| Health condition(s) or problem(s) studied | Sensitive skin |
| Intervention | Participants are enrolled in a randomized, double-blind, two-sequence, two-period crossover clinical trial comparing a metabolite-based soap (test product) with a neutral control soap. Participants are randomly assigned in a 1:1 ratio to one of two treatment sequences. Block randomisation is used to allocate participants to each group: Sequence AB: metabolite soap followed by control soap Sequence BA: control soap followed by metabolite soap Each treatment period lasts 4 weeks, separated by a 3-week washout period using a neutral cleanser. A 2-week washout phase using the neutral cleanser is performed before baseline. Participants wash the face and volar forearm twice daily with the assigned soap during each treatment period. The metabolite-based soap contains a blend of postbiotic metabolites derived from fermentation of lactic acid bacteria. The control soap has an identical base formulation but does not contain the metabolite complex. Clinical and mechanistic assessments are performed at baseline and at the end of each treatment period and include measurements of skin hydration, transepidermal water loss, sensitive skin questionnaire scores, microbiome analysis, and biochemical markers. Compliance is monitored through participant diaries and product weight verification. |
| Intervention type | Other |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) |
|
| Completion date | 05/02/2026 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Adult |
| Lower age limit | 20 Years |
| Upper age limit | 45 Years |
| Sex | All |
| Target sample size at registration | 70 |
| Total final enrolment | 60 |
| Key inclusion criteria | 1. Healthy male or female adults aged 20–45 years 2. Fitzpatrick skin types II–V 3. Self-reported sensitive skin with BoSS ≥“mild” at screening 4. Stable skincare and lifestyle habits for ≥4 weeks prior to enrollment 5. Agreement to avoid use of any other facial or forearm cleansers, topical actives, or cosmetics during the study 6. Willingness to provide written informed consent |
| Key exclusion criteria | 1. Presence of chronic skin disorders (eczema, psoriasis, dermatitis) 2. Use of systemic or topical antibiotics, corticosteroids, or retinoids within 8 weeks before baseline 3. Cosmetic procedures (peeling, laser, microneedling) within 3 months 4. Known allergy or hypersensitivity to soap ingredients 5. Pregnancy or breastfeeding 6. Participation in another clinical study within the preceding 3 months |
| Date of first enrolment | 06/10/2025 |
| Date of final enrolment | 23/10/2025 |
Locations
Countries of recruitment
- Japan
Study participating centres
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|
Editorial Notes
17/03/2026: Study's existence confirmed by the Japanese Society of Anti-Aging Nutrition (JAAN) Ethics Review Committee.
