As far as I know, there should be no theoretical reason for chronic
methadone intake being associated with a low milk supply.

Here in Toronto, most women in methadone programmes do not breastfeed.
Epidemiologically, they fit into the groups which rarely breastfeed,
and if they do want to breastfeed, they are often advised not to.

However, I have seen a couple of mothers in methadone programmes who
breastfed quite well.  The trouble in such a situation is that most of
us have had too few cases to make any general statement.

Jack Newman, MD, FRCPC