Most adolescents and young adults develop acne at some time in their lives, and the red, raised lesions can leave lasting scars.
Lasers, along with medications and light therapy, have previously shown potential as treatments.
But because no single cause of acne has been identified - it may result from the body's reaction to hormonal changes in adolescence, changes to the layer of skin where hair follicles form, or possibly bacteria - no treatment has been found to be fully effective.
Researchers at the University of Michigan found that one or two treatments with a laser performed on one side of the faces of 40 acne patients, aged 13 or older, made little difference.
"The fact that our study does not substantiate the positive results recently reported (in other studies) is not an indictment of laser therapy for acne in general, and does not necessarily rule out the possible role of this particular pulsed dye laser."
"However, it does suggest that additional well-designed studies are needed before the use of the pulsed dye laser becomes a part of acne therapy," study author Jeffrey Orringer wrote in the Journal of the American Medical Association.