I Am Breast Feeding, Can I Have PDT?

While there has never been a study on the use of PDT with Levulan or Metvixia or Allumera in women who are breast feeding, it is hard to imagine that any of the topically applied products would penetrate into the blood stream to affect breast milk.

There is no established safety information as far as I know about the use of PDT in breast-feeing

Laser and light treatments, including PDT, have not been tested for safety in pregnancy or breastfeeding. 

I would not see a problem with the blue light part of PDT, but Levulan is a Category C drug. Generally, a Category C drug, translates to a " do not use" unless the risks outweigh the benefits position in the nursing realm. For that reason, and the assumption you desire PDT for cosmetic reasons, I would delay such treatment until after your baby has been weaned. Congratulations, and enjoy your little one.