eMatrix delivers energy via RF or Radiofrequency . For a more in-depth explanation see the video below as I explain the treatment levels, and how the machine actually works. Obviously don't breast feed AT THE SAME time- that doesn't make sense and would be a logistical nightmare! But in between feeds, absolutely 100% fine. This is because the radio frequency pulse is delivered on the skin, and doses not affect breast milk in any way. Totally, 100% safe. If you are having local anaesthetic, especially a high concentration e.g.. 23/7- my recommendation is that you express feed prior, then wait 3-4 hours before resuming normal breast feeding. All the bestDr Davin LimLaser DermatologistBrisbane, Australia.