An inquest into eight overdose deaths at the Hamilton-Wentworth Detention Centre resumed Monday.
Officials are providing a more in-depth look at the impact opioids have on the body.
A panel of five jurors has already heard from the health-care services manager at the Barton Street jail about the criteria for methadone therapy for those trying to treat an opioid addiction.
According to Angela DiMarco, an inmate has to already be using methadone, pregnant, or a month away from release, to have access to it in jail.
DiMarco admitted she sees no harm in starting the therapy sooner.
She testified that medical staff tried to provide the same level of care as what is available outside the facility, but added security considerations make it difficult.
DiMarco revealed overdose-reversing drug naloxone is not available to the general population or corrections officers but most recently it has been made available to sergeants in addition to health-care staff.
She also provided details on signs of a potential overdose.
They ask, is the person taking 10 breaths or fewer in a minute? Are they confused, or unconscious? Is there suspicion of an overdose.
Attention will now turn to the adverse effects of opioids, those expected to be at play in the deaths of eight men between 2012 to 2016.
The inquest is expected to last six weeks and is examining the deaths of William Acheson, Trevor Burke, David Gillan, Peter McNelis, Stephen Neeson, Marty Tykoliz, Louis Unelli, and Julien Walton.
Experts in both toxicology and pathology will appear Monday at the inquest.
The jury can make recommendations to prevent similar deaths.