In the UK, Peter Bradshaw of The Guardian awarded the film a maximum five stars, calling it "a gripping psychological thriller about big pharma and mental health that cruelly leaves you craving one last fix". He praised the lead performance from Rooney Mara as "compelling" who "lays down the law with her presence. She demonstrates a potent Hitchcockian combination: an ability to be scared and scary at the same time, and Soderbergh's film manages to introduce its effects in some insidious, almost intravenous way".  The . Club ' s Scott Tobias called Mara "superb as the glue that binds this fractured psychological puzzle," and commended Soderbergh's sophisticated direction: " Side Effects screws around in its own thriller architecture, toying with feints of structure and clever bits of misdirection, and otherwise playing the audience like a fiddle. At this point in his career, Soderbergh pulls it off with the unpracticed ease of a maestro."  Robbie Collin of The Daily Telegraph awarded Side Effects a maximum five stars and also acknowledged its debt to earlier psychological thrillers. He wrote: "There's a lot of Alfred Hitchcock in what follows, but even more Henri-Georges Clouzot , with whose classic spine-tingler Les Diaboliques (1954) Soderbergh's film shares a poisonous tang".  Peter Travers of Rolling Stone praised the film's performances, the script and direction, writing "Soderbergh delivers ticking-bomb suspense laced with psychological acuity about a world where mood-altering meds are as disturbingly prevalent as social media". 
Physicians should advise patients to stop use of all PDE5 inhibitors, including VIAGRA, and seek medical attention in the event of a sudden loss of vision in one or both eyes. Such an event may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including possible permanent loss of vision, that has been reported rarely post-marketing in temporal association with the use of all PDE5 inhibitors. It is not possible to determine whether these events are related directly to the use of PDE5 inhibitors or to other factors. Physicians should discuss with patients the increased risk of NAION in individuals who have already experienced NAION in one eye. Physicians should also discuss with patients the increased risk of NAION among the general population in patients with a “crowded” optic disc, although evidence is insufficient to support screening of prospective users of PDE5 inhibitor, including VIAGRA, for this uncommon condition [see WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS ].