Recruiting
Phase 4

Topical Almond Oil vs. Hydroquinone

Sponsor:

UCLA

Code:

NCT04875715

Conditions

Skin Pigmentation

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Almond Oil

Hydroquinone Topical

Study Details

Brief summary:

The purpose of this study is to analyze facial pigmentation and skin microbiome changes after topical almond oil application, compared to the use of topical hydroquinone.

Conditions

Skin Pigmentation

Study ID

NCT04875715

Start date

Jul 1, 2021

Status verified date

Sep, 2026

Completion date

Dec 1, 2026

Anticipated

Primary completion date

Dec 1, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Premenopausal women of Fitzpatrick skin types 3 to 6

Exclusion Criteria:

  • Those with a nut allergy
  • Smoking is an independent risk factor and serves as a confounder for the development of facial aging \[18\]. Therefore current smokers, those that have smoked within the past year, and former smokers with greater than a 20 pack year history of smoking will be excluded.
  • Those with an autoimmune photosensitive condition or a known genetic condition with a deficiency in collagen production (such as Ehlers-Danlos syndrome) will be excluded as this can be a confounder for facial photoaging.
  • Hormonal medications or therapies will not be allowed unless they have been stable on their medications for at least 2 months. Examples include oral contraceptives, progesterone-based injections, and estrogen based hormonal replacement therapy.
  • Those who have undergone any cosmetic procedures to the face in the 4 months prior to enrollment in the opinion of the investigator. People that have undergone deeper chemical peels (TCA based peels) within 1 year prior to enrollment will also not be eligible.
  • Individuals who are unwilling to discontinue vitamin E containing supplements and food sources during the washout and intervention.
  • Individual who are unwilling to discontinue topical cosmetic products during the duration of the study.
  • Individuals who are not willing to engage in a two-week washout on topical treatments known to affect facial pigmentation and these agents will be restricted during the study period as well. These include topicals that contain:

  • Retinoids such as tretinoin, adapalene, retinol.
  • Antioxidant ingredients such as vitamin C or vitamin E.
  • Pigment-reducing agents such as hydroquinone, azelaic acid, kojic acid per the discretion of the investigator except for the hydroquinone that is provided in this study.
  • Topicals that contain a nut oil or nut extract as part of their ingredient list.
  • Furthermore, subjects will be asked to refrain from use of any other topical products for one week prior to each visit apart from the study agents supplied from this study.

Study Design

Enrollment

50 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Almond oil

Almond Oil Pressed Cold

active comparator: Hydroquinone

Hydroquinone 2% cream

Interventions

Almond Oil

Almond oil

Hydroquinone Topical

Hydroquinone 2% cream

Primary outcome measure

  • Intensity of facial pigment [ Time Frame: 16 weeks ]

Central Contacts and Locations

Central contacts

Iryna Rybak

916-551-2636irybak@ucdavis.edu

Alexis Carrington

aecarrington@ucdavis.edu

Locations

UC Davis Department of Dermatology, Clinical Trials Unit

Recruiting

Sacramento, California, United States, 95816

Contacts

Iryna Rybak, BS

916-551-2636irybak@ucdavis.edu

Alexis Carrington, MD

916-551-2636aecarrington@ucdavis.edu

Principal Investigator:

Raja K Sivamani, M.D.

More Information

Sponsor

University of California, Davis

Last update posted

Sep 14, 2026

Last verified

Sep, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-25. This information was provided to ClinicalTrials.gov by University of California, Davis on 2026-09-14. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.