Topical Application of Lactobacillus Reuteri for Androgenetic Alopecia

NCT07370519 | Recruiting Phase 2

• 1 other identifier: LL-KY-2025109-02
• Study Type: interventional
• Target: 388
• Locations: 1 country
• Sites: 1

Brief Summary

This is a single-center, randomized, double-blind, placebo-controlled clinical trial designed to evaluate whether topical application of Lactobacillus reuteri can safely and effectively treat androgenetic alopecia. The study is based on the concept that balancing the scalp's microbial community may support hair follicle function. Participants will be randomly assigned to one of four groups receiving either active probiotic solution, inactivated probiotic solution (control for non-viable bacterial effects), a saline placebo, or the standard treatment 5% minoxidil solution for 12 months. Neither participants nor assessing clinicians will know the assigned treatment. The main goal is to measure improvement in hair count per square centimeter after one year. Additional measures include changes in hair thickness and quality. This research seeks to provide high-quality scientific evidence on a new microbiome-targeting approach, offering future patients and healthcare providers insights into a potential alternative or complementary treatment strategy for hair loss.

Conditions

Androgenetic Alopecia (AGA)

Keywords

Androgenetic Alopecia; Lactobacillus reuteri

Outcome Measures

Primary Outcomes (1)

• Hair Density

  Hair density is quantified by counting all visible growing hairs in a unit area of the scalp using a trichoscope

  The follow-up periods are set at 1, 3, 6, and 12 months after the initial treatment

Secondary Outcomes (1)

• Hair Diameter

  The follow-up periods are set at 1, 3, 6, and 12 months after the initial treatment

Study Arms (4)

Test Group

EXPERIMENTAL

Daily application of 1 sachet containing Lactobacillus reuteri powder (≈10\^9 CFU) dissolved in 1 mL normal saline within a brown glass vial. After thorough mixing, 1 mL of the probiotic solution was topically applied to the scalp using cotton swabs following scalp cleansing. Participants refrained from hair washing for ≥6 hours post-application. Applied once daily for 12 months.

Biological: Lactobacillus reuteri

Inactivated Control Group

OTHER

Daily application of 1 sachet containing inactivated Lactobacillus reuteri powder (≈10\^9 CFU pre-inactivation) dissolved in 1 mL normal saline within a brown glass vial. After thorough mixing, 1 mL of the solution was topically applied to the scalp using cotton swabs following scalp cleansing. Participants refrained from hair washing for ≥6 hours post-application. Applied once daily for 12 months.

Biological: Inactivated Lactobacillus reuteri

Positive Control Group

ACTIVE COMPARATOR

Commercially available 5% minoxidil tincture was aliquoted into brown glass vials (1 mL/vial). Following daily scalp cleansing, 1 mL solution was topically applied to the scalp. Participants refrained from hair washing for ≥6 hours post-application. Applied once daily for 12 months.

Drug: 5% Minoxidil

Negative Control Group

PLACEBO COMPARATOR

Normal saline was aliquoted into brown glass vials (1 mL/vial). Following daily scalp cleansing, 1 mL solution was topically applied to the scalp using cotton swabs. Participants refrained from hair washing for ≥6 hours post-application. Applied once daily for 12 months.

Drug: Normal Saline

Interventions

5% Minoxidil DRUG

Commercially available 5% minoxidil was aliquoted into brown glass vials (1 mL/vial). Following daily scalp cleansing, 1 mL solution was topically applied to the scalp. Participants refrained from hair washing for ≥6 hours post-application. Applied once daily for 12 months.

Positive Control Group

Normal Saline DRUG

Normal saline was aliquoted into brown glass vials (1 mL/vial). Following daily scalp cleansing, 1 mL solution was topically applied to the scalp using cotton swabs. Participants refrained from hair washing for ≥6 hours post-application. Applied once daily for 12 months.

Negative Control Group

Lactobacillus reuteri BIOLOGICAL

Daily application of 1 sachet containing Lactobacillus reuteri powder (≈10\^9 CFU) dissolved in 1 mL normal saline within a brown glass vial. After thorough mixing, 1 mL of the probiotic solution was topically applied to the scalp using cotton swabs following scalp cleansing. Participants refrained from hair washing for ≥6 hours post-application. Applied once daily for 12 months.

Test Group

Inactivated Lactobacillus reuteri BIOLOGICAL

Daily application of 1 sachet containing inactivated Lactobacillus reuteri powder (≈10\^9 CFU pre-inactivation) dissolved in 1 mL normal saline within a brown glass vial. After thorough mixing, 1 mL of the solution was topically applied to the scalp using cotton swabs following scalp cleansing. Participants refrained from hair washing for ≥6 hours post-application. Applied once daily for 12 months.

Inactivated Control Group

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Patients meeting AGA diagnostic criteria (confirmed by medical history, clinical presentation, and trichoscopy) classified as Norwood-Hamilton stage II-IV or Ludwig grade I-III;
• Provision of informed consent and voluntary participation;
• Aged 18-60 years with generally good health status;
• No use of any hair loss medications within the past six months;
• Absence of alopecia areata, local infections, or neuromuscular disorders.

You may not qualify if:

• AGA progression \>5 years;
• Active skin disease (e.g., psoriasis flare) or uncontrolled diabetes/CVD;
• Investigator-assessed protocol non-feasibility.

Sponsors & Collaborators

• Shenzhen People's Hospital: lead

Study Sites (1)

Shenzhen People's Hospital

Shenzhen, Guangdong, China

RECRUITING

MeSH Terms

Conditions

Alopecia

Interventions

Minoxidil; Saline Solution

Condition Hierarchy (Ancestors)

Hypotrichosis; Hair Diseases; Skin Diseases; Skin and Connective Tissue Diseases; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Piperidines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Pyrimidines; Crystalloid Solutions; Isotonic Solutions; Solutions; Pharmaceutical Preparations

Central Study Contacts

Jianglin Zhang

CONTACT

+86 13873143466; zhang.jianglin@szgospital.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 17, 2026
• First Posted: January 27, 2026
• Study Start: January 25, 2026
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): June 1, 2027
• Last Updated: April 1, 2026

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)