The trial is a test case of a 1988 law passed by Congress that outlawed distributing steroids for non-medical reasons.
They have been indicted on charges of conspiring to distribute steroids.
The four have been charged with illegally distributing steroids and other performance-enhancing drugs to elite athletes.
McMahon was put on trial in 1994, accused of distributing steroids to his wrestlers.
Two Balco executives were among four people charged this month with illegally distributing steroids and other performance-enhancing drugs.
But designer drug laboratories like Balco have been accused of seeking to distribute potent steroids that don't test positive.
He served time in prison in 2005 after pleading guilty to conspiracy to distribute steroids and money laundering.
Anderson is one of four men charged with conspiring to distribute steroids to elite athletes and money laundering.
He is one of four men in the case charged with distributing steroids and laundering money.
He admitted yesterday to distributing steroids to athletes but was not asked in court to name the athletes.