Former 100m world record holder Asafa Powell will have to wait until 12 February to find out if he faces a two-year ban from athletics.
The 31-year-old is accused of taking the banned stimulant oxilofrine, but his trial was adjourned on Wednesday.
On day two of the hearing, a toxicologist claimed Powell would have gained no advantage from the drug.
Powell's camp have defended the manner in which coach Chris Xuereb, who the sprinter blames, was appointed.
"I simply relied on the referrals of well-known and trusted physios who we had worked with in the past," Powell's agent Paul Doyle told the hearing in Kingston.
Powell, who set a world record of 9.74 seconds in 2007, was one of five Jamaicans, along with former training partner Sherone Simpson, to test positive at the Jamaican national championships in June.
Professor Wayne McLaughlin of Caribbean Toxicology told the Jamaican Anti-Doping Commission trial that oxilofrine "does not improve speed".
Tests have shown the stimulant is present in a supplement known as Epiphany D1, a substance Powell and training partner Simpson, whose trial resumes on 4 February, claim Xuereb supplied.
The trainer denies supplying the supplement, but the court heard that he was also administering Powell's anti-inflammatory injections and Vitamin B12, despite not being certified as a doctor, massage therapist, chiropractor or physiotherapist.
On Tuesday, Powell told the court he did not list all his supplements at trials as he could not remember their names.