The goal of this clinical trial is to evaluate the safety and effectiveness of a poly-L-lactic acid (PLLA) dermal implant for the correction of nasolabial folds. The study also aims to determine whether the investigational product (FUYANMEI Poly-L-Lactic Acid) is non-inferior to the control product (Sculptra).

The main questions it aims to answer are:

• Is the effectiveness rate based on the Wrinkle Severity Rating Scale (WSRS) at 6 months after injection for the investigational group non-inferior to that of the control group?
• How does the investigational product perform in terms of global aesthetic improvement as assessed by blinded evaluators and by subjects?
• What is the safety profile of the investigational product, including the incidence, severity, and relatedness of adverse events (AEs), serious adverse events (SAEs), and device deficiencies (DDs)?

Researchers will compare the investigational PLLA implant to an approved PLLA implant using a prospective, randomized, evaluator- and subject-blinded, single-center, split-face controlled study design. Approximately 121 eligible participants will be enrolled.

Participants will:

• Receive treatment with the investigational product and the control product according to the split-face design
• Be followed for 24 months after injection
• Return to the clinic at 1, 3, 6, 12, 18, and 24 months post-injection for follow-up visits
• Undergo blinded evaluator assessments of WSRS and Global Aesthetic Improvement Scale (GAIS)
• Complete subject self-assessments of GAIS and treatment satisfaction
• Be monitored throughout the study for adverse events, serious adverse events, and medical device deficiencies

Inclusion Criteria:

1. Willing and able to provide written informed consent prior to any study-specific procedures.
2. Male or female subjects aged between 19 and 65 years.
3. Presence of bilateral nasolabial fold wrinkles with a Wrinkle Severity Rating Scale (WSRS) score of moderate (Grade 3) or severe (Grade 4) at baseline.
4. Willingness and ability to comply with all protocol-required follow-up visits and procedures.

Exclusion Criteria:

1. History of hypertrophic scarring or keloid formation.
2. Presence of active infection or dermatologic conditions at or near the intended injection site that may interfere with the evaluation.
3. Underwent major surgery within 3 months prior to study initiation.
4. Diagnosed with autoimmune diseases, malignancies, psychiatric disorders, or poorly controlled chronic medical conditions.
5. Prior treatment with or planned use of permanent dermal fillers at the intended injection site.
6. Prior treatment with or planned use of temporary fillers, collagen stimulators, or thread lifting at the injection site within 12 months prior to screening or during the study period.
7. Underwent or plans to undergo laser treatments to the mid- or lower face within 3 months prior to treatment or during the study period.
8. Underwent or plans to undergo ultrasound or radiofrequency skin tightening procedures to the mid- or lower face within 6 months prior to treatment or during the study period.
9. Known hypersensitivity to poly-L-lactic acid or any components of the investigational device, or any other significant allergy as deemed by the investigator to pose risk to the subject.
10. Planned surgeries or medications during the study period that may cause significant weight changes.
11. Pregnant or breastfeeding women, or women intending to become pregnant during the study period.
12. Participation in another interventional clinical trial that has not concluded within 30 days prior to screening, or plans to participate in another interventional clinical study during the course of this study.
13. Any other condition or situation that, in the opinion of the investigator, renders the subject unsuitable for study participation.