1：Experimental Design and Method Selection:

The study was a prospective comparative study including thirty patients with inflammatory and noninflammatory facial acne, assigned randomly and equally into two groups, the Nd:YAG and IPL groups. The patients received three sessions of laser 2 weeks apart.

2：Sample Selection and Data Sources:

Thirty patients of Fitzpatrick skin phototype III-V with inflammatory and noninflammatory facial acne were included. Exclusion criteria were pregnancy or lactation, systemic diseases, photosensitivity, history of hypertrophic scars or keloids, current anticoagulation therapy, previous treatment of face with an ablative laser, topical acne preparations or systemic antibiotic therapy within one month, and/or oral retinoids 6 months prior to the study.

3：List of Experimental Equipment and Materials:

Long-pulsed Nd:YAG (1064 nm) laser (Synchro HP, DEKA) using 7 mm hand piece by 40-50 Joules fluence and 40 ms pulse duration. IPL (The Nova light system?) treatment sessions using the appropriate filter (8-34 mm) to delivers a wavelength between 420 and 1200 nm in continuous mode with

4：0 J/cm2 fluence and three milliseconds pulse width. Experimental Procedures and Operational Workflow:

The treatment areas were cleaned; a thick layer of topical anesthetic EMLA? cream was applied for 90 minutes and then removed with dry gauze before the session. One pass over the lesions in the Nd:YAG Group, two passes, and an optical coupling gel applied to IPL Group patients. Ice packs were applied followed by sunscreens immediately after the session and sun avoidance advised.

5：Data Analysis Methods:

The clinical improvement was assessed by the reduction of lesions' number and regarded as an improvement score. Patients assessed their improvement subjectively using a four-point scale. Complications were recorded.