The goal of this clinical trial is to learn whether pharmacopuncture with Platelet-Rich Plasma (PRP) is effective for treating chronic neck pain in cervical myofascial syndrome related to the upper trapezius muscle. The main questions it aims to answer are:

1. Is pharmacopuncture with Platelet-Rich Plasma (PRP) effective in reducing chronic neck pain in patients with cervical myofascial syndrome related to the upper trapezius muscle?
2. Does PRP pharmacopuncture improve functional outcomes and quality of life in these patients?
3. Are there any adverse effects associated with PRP pharmacopuncture in this context?

Researchers will compare PRP pharmacopuncture to normal saline pharmacopuncture (placebo) to evaluate whether PRP provides greater effectiveness in reducing chronic neck pain in cervical myofascial syndrome related to the upper trapezius muscle.

Participants will:

• Receive a single session of pharmacopuncture therapy
• Undergo evaluations at week 2, week 4, and week 8 after the intervention

This is a clinical trial study to evaluate the effectiveness of PRP pharmacopuncture in patients with chronic neck pain in cervical myofascial syndrome related to the upper trapezius muscle. Participants are 60 males/females aged 18-59 years. They will be divided into two groups: (1) PRP pharmacopuncture and (2) Normal saline (placebo) pharmacopuncture. Each participant will receive a single pharmacopuncture treatment. Therapy efficacy will be assessed at week 2, week 4, and week 8 after the intervention.

Inclusion Criteria:

• Male or female, aged 18 to 59 years.
• Experiencing neck pain for more than 3 months (chronic).
• Neck pain classified as Grade I to III according to the Neck Pain Task Force classification.
• Presence of referred pain pattern on physical examination consistent with the distribution of the upper trapezius muscle.
• Visual Analogue Scale (VAS) score between 30 and 70 mm (out of 100 mm) during activity (e.g., daily activities or light exercise).
• Willing to participate in the study until completion and has signed the informed consent form.

Exclusion Criteria:

• Hemoglobin level <13 g/dL for males or <12 g/dL for females.
• Platelet count <150,000/μL.
• Presence of fever (≥37.5°C).
• Diagnosis of fibromyalgia.
• Structural abnormalities of the cervical spine other than degenerative changes, such as fractures, cervical spine injuries, space-occupying lesions (SOL), infections, neoplasms, or systemic diseases confirmed by radiographic imaging.
• History of cervical spine surgery.
• Presence of tumors, wounds, or skin infections at the needle insertion site.
• Diagnosed with blood disorders or currently taking anticoagulant or antiplatelet medications.
• History of hypersensitivity reactions to acupuncture (e.g., metal allergy, severe atopy, keloids, or other skin hypersensitivities).
• Uncontrolled cardiovascular disease or diabetes mellitus.
• History of pharmacopuncture therapy to the upper trapezius muscle within the past 6 months.
• Use of anti-inflammatory medication within the past 2 weeks.
• Currently pregnant or breastfeeding.