The Incredible Shrinking Woman (1981)

Lily Tomlin in an epic comedy (Give or take an inch)

After being exposed to a bizarre mixture of household chemicals, Pat Kramer begins to shrink. This baffles scientists, makes parenting difficult, warms the hearts of Americans, and captures the attention of a group of people who want to take over the world. This evil group plots to kidnap Pat and perform experiments on her so that they can eventually shrink everyone.