The goal of this clinical trial is to evaluate the efficacy of the novel lip product containing Caulerpa lentillifera extract on the appearance and perception of dark lips in Thai adults aged 18 to 60 who report concerns about darkened lips. The main question it aims to answer is: Can the novel lip product containing C. lentillifera extract will significantly improve the appearance and perception of dark lips in Thai adults by reducing hyperpigmentation compared to baseline measurements?

Participants will apply the lip product twice a day, in the morning after breakfast and before bedtime, and refrain from using other lip products throughout the clinical trial period (7 days).

Researchers will compare the result to baseline measurements

Inclusion Criteria:

• Understand the study protocol and provide informed consent after being informed of potential risks and benefits.
• Refrain from using any other lip products, including lipstick, lip gloss, or lip conditioners, during the study period.

Exclusion Criteria:

• Have a known allergy or sensitivity to cosmetic products or Caulerpa lentillifera.
• Are on medication one month prior to study commencement.
• Exhibit lip abnormalities such as malformation, inflammation, swelling, or sores.