Real world article
(written from a Production point of view)
(written from a Production point of view)
Referenced in the writers' first draft script of the Star Trek: Enterprise first season episode "Dear Doctor", a circulation enhancer was a type of medication used to counteract extreme cold. It had severe side effects.
In a letter to Doctor Lucas, Dr. Phlox advised Lucas to try taking a circulation enhancer in order to resist the frigid climate of Iyax, if Lucas could tolerate the associated side effects.