Hollywood's Greenest Mess Came From the Medicine Aisle

In 1984, Ghostbusters needed a lot of ectoplasm, and not the kind you could buy at a store. The effects crew had to invent something gooey, green, and safe to splatter on actors.

Practical effects ruled the era, so there was no digital shortcut. Whatever the team mixed had to look wet on camera, cling to costumes, and survive take after take under hot studio lights.

Their answer was a simple mix of water, green coloring, and methylcellulose, a thickener. Methylcellulose is also the bulk-forming ingredient in some over-the-counter laxatives.

That is why the goo behaved so well. Methylcellulose soaks up water and turns it into a thick gel, which gave the slime its slow, stretchy drip when it hit a jacket or a face.

The famous victim was Bill Murray, who gets slimed by Slimer in the hotel hallway. The mess was real, practical goo, not an optical trick. Murray's startled reaction sells it.

Sticky slime and expensive wardrobe do not mix. Cleanup was reportedly miserable, and cast members have joked over the years about how unpleasant the stuff was to wear.

So the next time Slimer glides through that hallway, remember the goo came from the same chemistry sitting in a pharmacy aisle. Hollywood's iconic slime was basically a thickener.