NCT04875715 · University of California, Davis
Prospective Evaluation of Topical Almond Oil vs Hydroquinone
What this study is about
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.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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.
Where
- Sacramento, California
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 12, 2025 · Source of record for eligibility and locations