A jury has heard how Majid Mustafa, 48, encouraged a man called Robert Lipinski to obtain the drug, which is usually associated with date-rape, to help him find out about a relationship his wife Renata Antczak was conducting.
Prosecutors at Doncaster Crown Court said he wanted to incapacitate Ms Antczak so he could use her fingerprint to access her mobile phone but he never got hold of any GHB.
The jury was not told during the trial that Ms Antczak was reported missing a year ago in Hull and has not been seen since.
The last known sighting of the 49-year-old from Hull was when she dropped her 11 year-old daughter off at school in the city on the morning of Tuesday, April 25, last year.
Specially-trained officers later conducted searches on grassland on Kingswood, close to Mrs Antczak’s home.
The jury was discharged today after Mustafa changed his plea to guilty of on a charge of intentionally encouraging an offence and was then given a conditional discharge for 12 months by Judge Mark Bury.
The court heard how he used various surveillance methods to try and find out what was happening with his wife.
But he also encouraged Mr Lipinski to get hold of GHB from Poland.
The court heard that Mr Lipinski was already trying to get hold of the drug in order to use it on his own wife.
The judge stressed that Mustafa never obtained the drug.
Sentencing him, Judge Bury made it clear that the offence he was convicted of had nothing to do with his wife's disappearance.
He said: "You are not charged with, still less convicted, in connection with her disappearance."
Judge Bury also said: "There are many people whose partners, unhappily, are unfaithful. There are very few people who would want to drug them with GHB to try and find out what was going on."
The judge said that he was taking the unusual step of imposing a conditional discharge partly because there had been no actual harm done to anyone and also because Mustafa had already spent five-and-a-half months in custody on remand last year.
But the judge said that period of remand could only have been imposed due to ongoing inquiries relating to Ms Antczak's disappearance.
Ms Antczak, 49, was last seen in the Kingswood area of Hull and was reported missing on April 25 last year.
Police have made a number of appeals to try and find her and the search continues to be a major inquiry for Humberside Police who launched a murder investigation.
Mustafa, of Beamsley Way, Kingswood, Hull, admitted one count of intentionally encouraging an offence.
The charge states that between March 30 and April 25 last year, he encouraged Robert Lipinski to obtain a noxious substance so that it could be unlawfully administered to Renata Antczak with the intent to injure, aggrieve or annoy.
Mustafa left court saying he just wanted to go back to Hull and see his family.