This is a shampoo and when applied to the hair and skin, almost none is absorbed into the
circulation through the skin (Hale says 2% of the total dose).  But, of that two percent, only a
small amount gets into the milk because the concentration in the blood is very low and only
what is in the blood can get into the milk.  First of all, the drug is rapidly metabolized.
Secondly, the small amount is diluted in a large amount of blood.  Furthermore, a fair amount
that is not metabolized, gets absorbed into the body fat.

This is safe.  Mothers should be encouraged to continue breastfeeding when using this.

Jack Newman, MD, FRCPC