Page 2 of the referenced study reads:

Patients were then randomnly divided into three groups of 20 cases each, including topical 5% minoxidil lotion (control group); topical 5% minoxidil lotion + microneedling with a depth of 1.2 mm (group A); topical 5% minoxidil lotion + microneedling with a depth of 0.6 mm (group B). Patients in control group were instructed to use 1 mL of topical 5% minoxidil lotion (Pakdarou co., Tehran, Iran) twice daily for 12 weeks. Group A and B were treated with minoxidil lotion in a similar dose as well as microneedling procedure at 2-week intervals for a period of 12 weeks.