Women considering surgery to receive breast implants should be warned of the risk of serious complications, including fatigue, joint pain and the possibility of a rare type of cancer, the Food and Drug Administration said on Wednesday.

Agency officials are urging manufacturers to print a boxed warning on the packaging of the implants, and to provide a checklist spelling out the risks for patients considering surgery. It will be left to doctors to review those risks with women seeking breast implants.

The measures are not mandatory and are now open to public comment and industry input. But the recommendations reflect a growing acknowledgment at the agency that implants may cause more harm in women than previously known.

Several years ago, the agency linked implants to a rare form of immune system cancer called anaplastic large cell lymphoma. In July, at the request of the F.D.A., one manufacturer, Allergan, recalled textured breast implants linked to the cancer.