Ventura County sheriff's deputies said 36-year old Duong Che knowingly gave his co-worker an edible without the victim's knowledge that it contained THC, also known as tetrahydrocannabinol.
THC causes the euphoric high found in cannabis.
The incident happened on March 12 at a restaurant in the 400 block of Moorpark Road in Thousand Oaks.
Deputies were first sent to the restaurant on a call of possible poisoning after the victim began to experience shortness of breath, confusion and disorientation. As a result, she was unable to continue working, officials said.
On Wednesday, detectives searched Che's car and found drugs, as well as a chocolate bar that was the same type given to the victim.
Detectives also say Che possessed 70 ecstasy pills and more than $600 in cash, leading to him being arrested for possession for sales of a controlled substance.
Police executed a search warrant at his Rosemead home and say they found more than $4,300 in cash, saying it was believed to be the proceeds from illegal drug sales.
He was booked at the Ventura County Sheriff's jail with bail set at $70,000. He posted bail and is scheduled for a court appearance on April 27.
Correction: An earlier version of this story stated the suspect gave his co-worker "an edible with the victim's knowledge." It has been corrected to "without the victim's knowledge."