Alberta Law Enforcement Response Teams says the drug is also known as the date-rape drug, but adds it's usually abused as a party drug.
The team seized 8.5 litres of GHB, along with methamphetamine, Percocet, Valium, six firearms, ammunition and $16,100 in cash, from a home in northeast Edmonton on June 18.
Police say GHB is colourless and odourless and was being sold in water bottles.
They warn even a small drink from an unsuspecting person or child could lead to fatal results.
Mark Boivin, 31; Chantel Garnier, 31; Kevin Jurach, 58; and Aaron Watt, 19, are facing 44 charges.