In her new book Open Heart, Open Mind, Hughes reveals she was suspended for three months after testing positive for the stimulant.
The cycling and speed skating Olympian told CBC's Adrienne Arsenault she does not know how it found its way into her sample.
"I do know that I didn't cheat. I can look myself in the eye and know ... that is my truth," Hughes said in her recent interview.
Kriellaars believes Hughes is telling the truth. He's the former chair of the Sports Medicine and Science Council of Manitoba's substance-use committee.
He said ephedrine use was rampant during the time Hughes tested positive, and many athletes innocently consumed the drug.
The stimulant is found in many seemingly benign products including, cold medications and Chinese herbal supplements.
Health Canada notes ephedrine is sometimes sold under different names including Ma Huang and Chinese Ephedra.
Ephedrine use was so common in sport, Kriellaars said in 2006, regulators began to allow small amounts of the drug.
Today, the World Anti-Doping Agency allows up to 10 micrograms per millilitre in urine for competing athletes.
While ephedrine may have a performance-enhancing effect, the health costs of abuse can be serious.
Health Canada warns against using ephedrine for "weight loss, body building or increased energy," adding it may cause such conditions as irregular heartbeats, seizures, psychosis and even death.
Right now in Canada, the only approved use is as a nasal decongestant.
According to the Sports Medicine and Science Council of Manitoba's annual survey of local athletes, current use of ephedrine ranges from two per cent to 20 per cent in the province.
Also on HuffPost