Mumbai, March 27 : Actor Jonathan Majors is suspected of using an anabolic steroid during his alleged assault on his girlfriend. Following his domestic violence arrest over the weekend, the actor was accused of taking a dangerous steroid while filming "Creed III", reports aceshowbiz.com. The drug is believed to be what led to his outburst during an argument with the woman he was dating. "He was taking (steroids) while filming ('Creed III'). I can't say what he was taking, but people on staff were saying that he was on tren," a source, who allegedly worked with the 33-year-old hunk on the set of the movie, told Media Take Out. According to the website, Tren, or trenbolone acetate, is a popular synthetic anabolic steroid that's estimated to be three to five times more potent than testosterone, according to the outlet. The FDA does not allow its use on human beings and it is only available to use on cattle. However, it is being illegally utilised by athletes to amplify muscle strength and mass. It's regarded as a high risk, high reward steroid. The use of the drug comes with a ton of very scary side effects. In addition to it damaging the male reproductive system, Tren can lead to severe emotional instability and possible psychosis. Speculation previously arose that Jonathan used steroids after he gained weight in 18 months for his "Creed III" role. "I am beginning to suspect that Jonathan Majors may be using anabolic steroids," one person wrote on Twitter last year. Another chimed in, "Jonathan Majors did a wheelbarrow full of steroids for Creed III." The actor, however, has explained that his body transformation was the result of rigorous training and diet regimen he followed. He revealed that he consumed a whopping 6,100 calories per day, which is equivalent to six full meals. The 'Ant-Man and the Wasp: Quantumania' star said he took his role as Killian Maddox very seriously and gave it his all when it came to his training. He followed an intense workout routine, which included two sessions of two hours each day, and even added a third session after filming. Jonathan was arrested on Saturday morning, March 25 after an alleged domestic dispute with his girlfriend. He is being accused of slapping his partner when she tried to view the messages before putting his hands around her neck, ultimately resulting in visible injuries. Among them were a "laceration behind her ear, redness, and marks to her face." He has been charged with two counts of assault in the third degree, aggravated harassment and attempted assault. His rep, however, has insisted that "he has done nothing wrong," adding, "We look forward to clearing his name and clearing this up." His defence lawyer is also confident that "all charges will be dropped" in the case. The attorney added, "All the evidence proves that Mr. Majors is entirely innocent and did not assault her whatsoever. Unfortunately, this incident came about because this woman was having an emotional crisis, for which she was taken to a hospital yesterday." Although Jonathan maintains his innocence, the U.S. Army pulled his "Be All You Can Be" ad campaign in the wake of his domestic violence arrest. Two ads featuring the actor had been released prior to the assault allegations. /IANS