A Third Proof-of-Concept Study to Evaluate the Efficacy of NOBO, a Novel Postbiotic, in Controlling Axillary Odor in Healthy Adults

A Randomized, Double-Blind, Placebo-Controlled, Split-Axilla, Proof-of-Concept Study #3 to Evaluate the Efficacy of NOBO, a Novel Postbiotic, in Controlling Axillary Odor in Healthy Adults

The goal of this clinical trial is to evaluate the performance of NOBO, a yeast-based fermentation product (postbiotic) designed to control axillary odor, in controlling axillary odor in healthy male and female adults age 18 - 70 with confirmed self-perception of body odor. The main question it aims to answer is: Does NOBO decrease self-perceived odor of the intervention axilla compared to the placebo axilla at any time point? Researchers will compare the intervention axilla odor score to the placebo axilla odor score to see if there is a difference in self-perceived odor. Participants will:

• be given a NOBO deodorant spray and a placebo deodorant spray (each assigned to one axilla)
• self assess body odor
• self assess skin irritation

Study Overview

• Status: Enrolling by invitation
• Conditions: Body Odor
• Intervention / Treatment: Other: NOBO postbiotic; Other: Placebo

Detailed Description

The study aims to evaluate the performance of NOBO, a yeast-based fermentate designed to control axillary odor, in controlling axillary odor. This third efficacy study of NOBO serves the purpose of validating the fermentate's efficacy and de-risking future external clinical studies.

For this study, a total of 14 subjects will be recruited based on the recruitment requirements. The target population for this study is healthy male and female adults age 18 - 70 with no existing skin conditions (e.g., eczema, psoriasis, contact dermatitis) and no known allergies to skin treatment products or cosmetics, toiletries, and/or topical drugs, with confirmed self-perception of body odor. All assessments are conducted via electronic surveys through an internal data collection platform.

On Day -1 to Day 0, each subject goes through a wash-in period with controlled washing with only unscented soap; no use of underarm product is allowed.

Participants are randomly assigned a treatment axilla: either left or right. One axilla (intervention axilla) will receive NOBO for the full duration of the intervention period. The other axilla (control axilla) will receive a placebo for the full duration of the study.

Throughout the study, participants perform self-assessment of odor that includes assessing which axilla has stronger odor and rating the odor of each axilla using a standard odor rating scale (0-5). On Day 1 (AM) the subject performs the baseline self assessment of axillary odor and skin irritation. The subject then applies the deodorants to each axilla and self assesses odor immediately after the first application. On Day 1 (PM), ~12 hours after Day 1 AM application, the subject self assesses odor and applies the deodorants to each axilla again. On Day 2 (AM), the subject applies the deodorant to each axilla. On Day 2 (PM), the subject self assesses odor and applies the deodorant to each axilla. On Day 3, no underarm washing is allowed. On Day 3 (AM), the subject applies the deodorant to each axilla. On Day 3 (PM), the subject self assesses odor and skin irritation on each axilla.

Observing a decrease in self perceived odor of the intervention (NOBO) axilla compared to the placebo axilla at any post-baseline timepoin

• Study Type: Interventional
• Enrollment (Estimated): 14
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • Brooklyn, New York, United States, 11205
      • Kingdom

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age: The subject is an adult between 18 and 70 y.o.
• Skin health: The subject has no active skin conditions or lesions in the axillary region and no existing skin conditions (e.g., eczema, psoriasis, contact dermatitis).
• Skin allergies: The subject has no known allergies to skin treatment products or cosmetics, toiletries, and/or topical drugs.

Exclusion Criteria:

• Subject is pregnant, nursing, or planning to become pregnant in the next 6 months.
• Subject is an insulin-dependent diabetic.
• Subject has been diagnosed or treated for cancer in the past 5 years.
• Subject is currently using or has not used in the past two weeks any systemic antibiotics.
• Subject is currently using or used within the last month any topical medications, over-the-counter (OTC) or prescription products on the underarms.
• Subject is currently taking or plans to take during the study any anti-inflammatory for a chronic condition (except 81 mg-Aspirin per day), immunosuppressant, antihistamine, or sedative medications (i.e. containing antihistamines like Tylenol PM, Nyquil, etc.).
• Subject is currently participating in another underarm clinical trial. Subjects may participate in other studies as long as the same test sites are not used or are testing similar products.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: NOBO deodorant; The NOBO deodorant is composed of ≤2.6% yeast fermentation product and 10% ethanol in water. A dose is 0.48 mL per axilla for female subjects (3 actuations) or 0.64 mL per axilla for male subjects (4 actuations), delivered twice a day.	Other: NOBO postbiotic; The active ingredient in the NOBO deodorant is a yeast-based fermentation product (postbiotic) of the Starmerella genus.
Placebo Comparator: Placebo deodorant; The placebo deodorant is composed of 10% ethanol in water. The placebo deodorant contains the same concentration of ethanol as the NOBO deodorant. A dose is 0.48 mL per axilla for female subjects (3 actuations) or 0.64 mL per axilla for male subjects (4 actuations), delivered twice a day.	Other: Placebo; The placebo deodorant is composed of 10% ethanol in water

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Axillary odor self assessment (comparative)	Comparative assessment is simply a measurement of which axilla (left or right) smells worse.	At baseline (before application), immediately after first application, Day 1 PM, Day 2 PM, and Day 3 PM

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Axillary odor self assessment (on a 0-5 scale)	A 0 on the odor scale corresponds to "no axillary odor"; a 5 corresponds to "very strong axillary odor"	at baseline (before application), immediately after first application, Day 1 PM, Day 2 PM, and Day 3 PM
Skin irritation (pain & redness) self assessment (0-4 Draize scale; 0-10 pain scale)	A 0 on the Draize scale corresponds to no redness/edema; a 4 on the Draize scale corresponds to severe redness/edema. On the 0-10 pain scale, 0 = No pain at all, 5 = Moderate pain, 10 =Severe or unbearable pain.	at baseline (before application) and Day 3 PM

Collaborators and Investigators

• Sponsor: Kingdom

Study record dates

Study Major Dates

• Study Start (Estimated): July 27, 2026
• Primary Completion (Estimated): July 31, 2026
• Study Completion (Estimated): July 31, 2026

Study Registration Dates

• First Submitted: July 21, 2026
• First Submitted That Met QC Criteria: July 21, 2026
• First Posted (Actual): July 24, 2026

Study Record Updates

• Last Update Posted (Actual): July 24, 2026
• Last Update Submitted That Met QC Criteria: July 21, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Deodorant; Body odor
• Additional Relevant MeSH Terms: Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Body Odor
• Other Study ID Numbers: NOBO105C01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is no reason to share IPD from this study with other researchers.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No