During the show's heyday, children who met Larisa Oleynik (and were too young to understand special effects) would sometimes ask her to "morph" for them. Rather than try to explain things, she would quickly glance around, then tell them "Not here - everybody would see!".
There was some minor controversy about a scene in the pilot of the series, in which after Alex's transformation into liquid, she reforms into human form nude (behind some boxes, no actual nudity shown.) While somewhat controversial, this scene was featured in every season 1 intro sequence.
The show was a major part of Nickelodeon's Saturday night programming block, SNICK, intended as something of a replacement for Clarissa Explains it All, which had just ended its run around that time.
In the United Kingdom's release of the season 1 DVD in 2012, when it was suggested by the BBFC (British Board of Film Classification) that anyone under 15 should not purchase a copy. The reason given was that in one scene a "child character" hides inside a tumble dryer, and the danger of doing such a thing is never addressed. The BBFC claimed that instead of cutting the scene, the distributor said they were fine with the rating because it was aimed for "an adult 'nostalgia' market" and not for children who wouldn't be familiar with the show anyway.
The show is noteworthy for being the television debut of a young Jessica Alba. When the show's first season was released on DVD circa 2007, the DVD plastered Alba's name all over the cover and even billed her as the co-star, most likely in an effort to sell more copies. In actuality, she only appeared a handful of times, and only in a supporting capacity.