From Piranha and The Howling to The Burbs and Gremlins, few directors of the VHS era mastered the tricky balance of humor and horror as well as Joe Dante. Innerspace’s billing as a sci-fi-rom-com suggested there’d be little need to cover your eyes, yet the 1987 story of a shrunken man navigating the body he’s accidentally been injected into often resembles a Cronenberg-esque chiller.

Innerspace sees Dennis Quaid’s disgraced Navy aviator Tuck sign up for a hush-hush experiment in which he’ll be miniaturized and jabbed into an unsuspecting rabbit. But a rival organization gets wind of this new technology, and after being chased by their relentless heavy Mr. Igoe (Vernon Wells) for the syringe storing Tuck’s tiny frame and submersible pod, panicked and wounded chief scientist Ozzie (John Hora) thrusts it straight into the closest person.

That unfortunate passerby is Jack Putter (Martin Short), a nerdy and neurotic supermarket clerk who couldn’t look less like the hero of the hour if he tried. Even before all the body horror, Dante ramps up the anxiety levels, first with that tense and slightly surreal cat-and-mouse through a shopping mall populated by people in animal costumes, and then when Jack’s recurring bad dream about mistakenly charging a customer 100 grand at the checkout comes true.

But Innerspace truly gets under the skin when Tuck, who fell unconscious at the point of impact, awakens to discover his new home isn’t of the leporid kind. You may recall how obvious inspiration Fantastic Voyage shrunk an entire submarine crew to help repair an injured scientist from the inside, but while it was always obvious Raquel Welch and company were simply wandering through various sound stages, advances in special effects mean Tuck’s journey still looks impressively realistic. It’s often wince-inducing too.

“It was like someone had suddenly shoved a white-hot sewing needle through the pupil of my eye,” Jack tells his colleagues after Tuck implants a camera on his optic nerve. Further torturing the squeamish, a detour to the ear canal allows the pair to communicate, even if hypochondriac Jack initially believes he’s been possessed by the devil and is subsequently diagnosed with theistic hysteria. Short has perhaps never bettered this masterclass in physical comedy as a man who suddenly lacks full control of his body.

Jack eventually accepting that he’s inhabiting a pea-sized dweeb allows Innerspace to further explore the wonders and weirdness of the human body. After battling another gun-toting henchman, for example, Jack almost suffers cardiac arrest when his rapid pulse sends Tuck hurtling dangerously close to his heart.

In the scene most likely to have scarred the Blockbuster generation for life, a shrunken Mr. Igoe — also injected into Jack against his will to kill Tuck and retrieve a vital computer chip — gets graphically dissolved in bubbling gastrointestinal acid produced by an uptake in stress. “You just digested the bad guy,” goes the film’s most memorable zinger.

Innerspace’s concept and the supposed science behind it may be ridiculous. However, its visualization of how the body can be its own worst enemy is never less than captivating. From the vast sea of floating blood cells to all the pulsing veins and throbbing arteries, the film’s anatomical visual effects were fully deserving of their Oscar.

Even the film’s more comedic elements possess a certain level of yuck. Teetotaler Jack’s madcap dance routine to Sam Cooke’s “Twistin’ the Night Away” only occurs because Tuck wanted to fill his flask with alcohol, perhaps ignoring the fact by the time it got through Jack to him, it would be mixed with saliva and all kinds of bacteria. Elsewhere, Jack’s head looks like it’s going to explode Scanners-style when his facial muscles are rapidly manipulated to look like Robert Picardo’s scene-stealing fixer The Cowboy. And the moment when Jack briefly fears Tuck may have exited his body while using the urinal may well have given The Boys producers a few ideas.

Thankfully, Tuck doesn’t escape via the urethra, but through Jack’s nostrils with a sneeze brought on by an allergy to hairspray just moments before his oxygen supply was due to run out. Just in case you haven’t already been grossed out enough, the mucus-covered pod lands squarely on a scientist’s face. The realization Jack would otherwise have had a corpse floating around his insides that could potentially interfere with his organs at any moment only adds to all the nightmare fuel.

The fact Innerspace that was marketed as a fun for all the family caper proves the ‘80s were on a whole different level. Sure, there’s plenty of amusing slapstick, cartoonish villainy, and even a love story, albeit one that becomes increasingly bizarre; an icky kiss between Lydia (an under-utilized Meg Ryan) and Jack transports Tuck into his girlfriend’s body where he sees their unborn baby up close. However, it’s the genuine sense of jeopardy — take note Ant-Man and the Wasp — and visceral tour of the body that makes the film an underrated, if occasionally stomach-churning, gem.

Innerspace is streaming on HBO Max until March 31.