Saw this headline in the local newspaper.

Woman, who takes 15-pill cocktail, drives on curb

Are the commas correct?

The commas are wrong, and so is the hyphen..
"...who takes 15 pill cocktail…" is not an 'interruption' but (i) an essential reference to the woman and (ii) goes towards explaining why she was driving so.

Hence:

Woman who takes 15 pill cocktail drives on curb.

There's nothing wrong with the original headline.

The information between the commas is parenthesis (additional information) so commas are fine.

The hyphen in '15-pill' is correct as it forms a compound adjective describing the cocktail.