This Post-Market Clinical Follow-Up (PMCF) survey aims to descriptively evaluate the clinical performance and safety of saypha® filler when used under routine clinical practice for the correction of moderate to severe nasolabial folds (NLFs). The survey is conducted in accordance with the device's Instructions for Use (IFU) and consists of a combined prospective and retrospective, non-interventional, observational design across 1-2 European sites with established experience in aesthetic treatments and standardized documentation practices. The survey will use exclusively real-world clinical data collected during routine care and will not alter, influence, or prescribe any aspect of treatment.

The primary objective is to describe changes in NLF severity following treatment with saypha® filler, using a validated 5-graded photonumeric NLF Scale routinely applied in aesthetic practice. Secondary objectives include documenting the maximum volume administered during initial and touch-up treatments, determining the highest administered dose without associated safety concerns, evaluating safety outcomes through the reporting of adverse events (AEs), adverse device effects (ADEs), and device deficiencies (DDs), and describing visible aesthetic changes as assessed by treating physicians at multiple follow-up visits. Additional outcomes include the descriptive summary of aesthetic improvement through the modified Global Aesthetic Improvement Scale (mGAIS) and participant-reported satisfaction, collected where this aligns with site routine.

Participants are eligible if they received (or are planned to receive) saypha® filler for moderate to severe NLFs as per the IFU, are ≥18 years old, and provide informed consent for the use of their routine clinical data. Prospective participants will be informed about the survey only after their routine treatment has been completed. Retrospective participants may be included if their treatment occurred within the past six months and sufficient routine documentation exists. Individuals may be included if data are available for at least two follow-up visits within the 6-11-month period post-treatment (corresponding to Visit 3 and Visit 4). Exclusion criteria include concurrent clinical study involvement that may interfere with assessment, prior permanent fillers or recent aesthetic procedures in the treatment area, medically supervised weight-loss programs during follow-up, and pregnancy or breastfeeding due to IFU contraindications.

The survey aims to collect evaluable data from 30 participants, with allowance for up to 10% additional participants to compensate for potential dropouts. Each participant contributes data for the left and right NLF, which will be analyzed both separately and combined. This sample size ensures sufficient descriptive precision for key safety and performance outcomes. No hypothesis testing is planned; all analyses will be descriptive, employing summary statistics for categorical and continuous variables. No imputation will be performed for missing data.

Data will be collected via standardized Case Report Forms (CRFs) and an electronic data capture (EDC) system, ensuring consistency across sites. Site personnel will be trained on survey procedures and CRF completion. Monitoring activities include periodic data checks to minimize discrepancies and ensure accuracy. Data security measures include pseudonymization, compliance with GDPR, restricted access to authorized personnel, and comprehensive audit trails within the EDC system.

Safety information-including adverse events, adverse device effects, and device deficiencies-will be documented according to each site's established clinical practice. The survey does not require any additional visits, diagnostic measures, or procedures beyond routine care. All data derive exclusively from regular clinical documentation already generated through standard treatment pathways.

Upon completion of the data collection phase, each site will undergo a closeout to ensure CRF completeness and resolution of outstanding queries. A final report will summarize the descriptive findings related to clinical performance, aesthetic outcomes, and safety of saypha® filler in real-world practice. The final study outcomes will contribute to the device's ongoing post-market clinical evaluation and will support regulatory compliance under the Medical Device Regulation (MDR), Annex XIV, Part B.

Inclusion Criteria:

1. Individuals treated or planned to be treated with saypha® filler for moderate to severe nasolabial folds as per IFU.
2. Individuals 18 years of age or older.
3. Individuals who have provided consent for use of their data, either prospectively before, at their first visit, or retrospectively at any point during or after the follow up period.
4. Individuals who are willing to have at least two visits within the surveys' 6 to 11-months period or have already completed the follow-up visits and data are available for at least two visits within the survey's 6 to 11-month period, corresponding to Visit 3 and Visit 4.
5. For retrospective included Individuals who have data available on a 5 grade, validated photo numeric NLF scale and the modified GAIS at baseline and for at least two visits within the survey's 6 to 11-month period, corresponding to Visit 3 and Visit 4, or individuals who are willing to attend any follow-up visit with data collected independently for the left and right nasolabial fold (requiring two assessments each per visit).

Exclusion Criteria:

1. Individuals involved in other clinical studies that may interfere with the assessment of this device's performance or safety.
2. Individuals with facial plastic surgery, tissue augmentation with silicone, fat or another non-absorbable substance (permanent fillers) in the area of device application.
3. Individuals that have an implantation of absorbable and non-absorbable facial dermal fillers in the treatment area in the preceding twelve months.
4. Individuals where the skin of the nasolabial region is affected by aesthetic treatments (e.g. laser therapy, absorbable and non-absorbable sutures (threads), microneedling and/or botulinum toxin within the last twelve months, dermabrasion and mesotherapy within the last six months, chemical peeling within the last three months) or planning to undergo such procedures during the survey period.
5. Individuals who had facial lipolysis, including submental fat treatments, within last month prior to enrollment and during the survey period.
6. Individuals currently undergoing a medically supervised or self-initiated diet program aimed at significant weight loss or metabolic change at the time of treatment and/or during the follow-up period.
7. Pregnant or breastfeeding women, as treatment during pregnancy or lactation is contraindicated according to the product's Instructions for Use (IFU).

Participants are adults (≥18 years) who received routine clinical treatment with a hyaluronic acid dermal filler for the correction of moderate to severe nasolabial folds. The population includes both prospective participants, who consent after completion of their routine treatment, and retrospective participants whose treatment occurred within the last 6 months and whose routine clinical data are available. Individuals must have at least two documented follow-up visits within 6-11 months post-treatment or be willing to attend such visits. Data derive exclusively from routine clinical practice, including physician-assessed NLF severity, aesthetic improvement ratings, administered volumes, and safety outcomes.