This study aimed to evaluate the safety and effectiveness of stabilized Hyaluronic Acid Injection under the brand name Perleux body for neck skin rejuvenation, elasticity improvement, and hydration enhancement.

Primary objective: Elasticity (R0, R2, and R5) improvement from baseline in neck area at weeks 8 and 16 Hypothesis: Perleux body (produced by Espad Pharmed Co.) has acceptable efficacy and safety profile for neck skin rejuvenation, elasticity improvement, and hydration enhancement.

Secondary objectives: Effectiveness and safety assessment of Perleux body Study design: This is a phase IV, single-arm, and pre-post study Setting: Subjects will be treated with 2cc of Perleux body at baseline. After 4 weeks, a touch-up injection will be performed to achieve optimal improvement.

Inclusion Criteria:

• Age between 35 and 60 years (inclusive)
• The presence of visible signs of skin aging, mainly dry neck skin, rough neck skin, loss of elasticity and clear lines and wrinkles (grades 2, 3, and 4 based on the IBSA Neck Laxity Scale)
• Able to follow study instructions and likely to complete all required visits
• Signing the informed consent form and agreeing to the 6-month follow-up

Exclusion Criteria:

• Previous treatment with fillers containing hyaluronic acid in the neck area during the last year
• History of using RF, rejuvenating lasers or intense pulsed light in the last 6 months
• Having systemic diseases that affect skin health, such as vascular collagen diseases, diabetes, hypothyroidism, liver and kidney failure.
• History of systemic use of drugs affecting the skin such as glucocorticoids, isotretinoin, immunomodulators and hormonal drugs in the last 3 months
• History of taking supplements containing collagen, hyaluronic acid and vitamin C in the last 3 months
• History of using topical corticosteroids and retinoids in the last 4 weeks
• Using topical cosmetic products containing anti-aging ingredients in the last 2 weeks
• Pregnant and lactating women
• History of active smoking during the last 2 years
• Major change in lifestyle including diet and physical activities and sun exposure during the study
• History of previous allergy to hyaluronic acid or lidocaine
• Any inflammation, active infection, unhealed old wound, and skin lesions in the injection area
• Using any anticoagulant product, NSAID, or any other drug that increases the risk of coagulation disorders, in the last 7 days
• History of anaphylactic shock
• Being prone to hypertrophic scar formation
• History of autoimmune disease or immune deficiency or using immunosuppressant drugs