The goal of this clinical trial is to investigate GHK and GHK-Cu blood levels pre- and post-intervention in healthy adults, and to investigate the efficacy of X39 patch on GHK and GHK-Cu blood levels in healthy adults compared to a placebo. The main questions it aims to answer are:

• What is the change in GHK and GHK-Cu levels from baseline to Day 8?
• What is the difference in the change in GHK and GHK-Cu levels from baseline to Day 8 between the X39 patch and placebo? Researchers will compare X39 patches to placebo patches to evaluate their effects on circulating blood levels of GHK and GHK-Cu in healthy adults.

Participants will be asked to complete a questionnaire and use the X39 patch or placebo patch.

Inclusion Criteria:

1. Males and females 35 years and older

2. Females not of child-bearing potential, defined as those who have undergone a sterilization procedure (e.g. hysterectomy, bilateral oophorectomy, bilateral tubal ligation, complete endometrial ablation) or have been post-menopausal for at least 1 year prior to screening Or,

   Individuals of child-bearing potential must have a negative baseline urine pregnancy test and agree to use a medically approved method of birth control for the duration of the study. All hormonal birth control must have been in use for a minimum of three months. Acceptable methods of birth control include:

   • Hormonal contraceptives including oral contraceptives, hormone birth control patch (Ortho Evra), vaginal contraceptive ring (NuvaRing), injectable contraceptives (Depo-Provera, Lunelle), or hormone implant (Nexplanon)
   • Double-barrier method
   • Intrauterine devices
   • Non-heterosexual lifestyle and agrees to use contraception if planning on changing to heterosexual partner(s)
   • Vasectomy of partner at least 6 months prior to screening
   • Abstinence and agrees to use contraception if planning on becoming sexually active during the study

3. Agrees to refrain from vigorous physical activity, alcohol consumption, and taking NSAIDs 24 hours prior to study visits

4. Agrees to maintain current lifestyle habits (diet, physical activity, medications, supplements, and sleep) as much as possible throughout the study

5. Willingness to complete questionnaires, diaries and to complete all clinic visits

6. Provided voluntary, written, informed consent to participate in the study

7. Healthy as determined by medical history as assessed by the Qualified Investigator (QI)

Exclusion Criteria:

1. Individuals who are pregnant, breast feeding, or planning to become pregnant during the study
2. Allergy or sensitivity to the adhesive used for wearing the investigational patch
3. Self-reported tattoos, skin conditions, or sensitive skin at or around the area of application
4. Diagnosis with Wilson's disease
5. Current use of prescribed and/or over-the-counter (OTC) medications, supplements, and/or consumption of food/drinks that may impact the efficacy of the investigational product (Sections 7.3.1 and 7.3.2)
6. Unstable metabolic disease or chronic diseases as assessed by the QI
7. Current or history of any significant diseases of the gastrointestinal tract as assessed by the QI
8. Unstable hypertension. Treatment on a stable dose of medication for at least 3 months will be considered by the QI (See Section 7.3)
9. Type I or Type II diabetes
10. Significant cardiovascular event in the past 6 months. Participants with no significant cardiovascular event on stable medication may be included after assessment by the QI on a case by-case basis
11. History of or current diagnosis with kidney and/or liver diseases as assessed by the QI on a case by-case basis, with the exception of history of kidney stones in participants who are symptom free for 6 months
12. Self-reported confirmation of current or pre-existing thyroid condition. Treatment on a stable dose of medication for at least 3 months will be considered by the QI
13. Major surgery in the past 3 months or individuals who have planned surgery during the course of the study. Participants with minor surgery will be considered on a case-by-case basis by the QI
14. Cancer, except skin basal cell carcinoma completely excised with no chemotherapy or radiation with a follow up that is negative. Volunteers with cancer in full remission for more than five years after diagnosis are acceptable
15. Individuals with an autoimmune disease or are immune compromised as assessed by the QI
16. Self-reported confirmation of a HIV-, Hepatitis B- and/or C-positive diagnosis as assessed by the QI
17. Self-reported confirmation of blood/bleeding disorders as assessed by the QI
18. Use of prescribed medical cannabinoid products
19. Chronic use of cannabinoid products (>2 times/week). Occasional users will be required to washout and abstain for the duration of the study period
20. Regular use of tobacco or nicotine products in the past six months, as assessed by the QI. Occasional users will be required to washout and abstain for the duration of the study period
21. Alcohol intake average of >2 standard drinks per day as assessed by the QI
22. Alcohol or drug abuse within the last 12 months
23. Participation in other clinical research studies 30 days prior to baseline, as assessed by the QI
24. Individuals who are unable to give informed consent
25. Any other condition or lifestyle factor, that, in the opinion of the QI, may adversely affect the participant's ability to complete the study or its measures or pose significant risk to the participant

Part 1: Single-arm, open-label & Part 2: Randomized, double-blind, placebo controlled, parallel