"Positive Reaction" is an upbeat and catchy pop song with a strong dance beat and synth-driven melody.
The lyrics are about a woman who is feeling empowered and positive after a breakup, and are delivered with a confident and enthusiastic vocal performance from Smith.
In review of 31 October 1987 Richard James of Number One called "Positive Reaction" "typical high energy crap".
He wrote: "After Stock Aitken and Waterman did a classic like Sinitta's "Toy Boy", this in comparison sounds like they found it lying in a box said 'oi Mandy, sing that one luv'.
"[1] Jerry Smith of British magazine Music Week described the song as "stretching [SAW's] rapidly thinning credibility even further".