Bonnie Jones:

Most companies now offer various types and sizes of soft inserts. These inserts
are often touted as having various properties such as making the mothers more
comfortable, increasing milk supply, or improving pumping over all. Most of
these claims are based on empirical observations rather than a formal study.

To my knowledge there have been no studies published on the effectiveness of
these type
of inserts. Before considering use of such inserts, I would request such studies
from the manufacturer.

Inserts tend to add to the expense of pumping especially if one is double
pumping and the cost needs to be carefully considered in relation to benefits
(if any) that might be present.

Richard Weston
Medela Inc.