The 19th annual service proceeded just as the founders intended when they first lodged a memorial rock in Weston Park in 1996: the crowd sat on blankets or the grass, petals from blooming trees floating around them as they listened quietly to the names of those lost.

Twenty years since the Families and Friends for Drug Law Reform advocacy group was founded, grief and heartache still dominated the ceremony.

However, there was also hope: both for healing and a chance to lobby governments to make the changes those left behind believed would prevent other families from experiencing the same suffering.

Families and Friends for Drug Law Reform president and founding member Brian McConnell said Monday's ceremony was a chance to reflect on both the people lost and the progress made since the mid-1990s.

"We started at a time when the words 'drug law reform' were something that no one talked about," he said.

"But now, today, you can talk about drug law reform and it's not something people will frown on you about."

Mr McConnell said the annual ceremony was a way to keep the issue "out in the open" and develop the least harmful drug policy possible.

He said that came from following overseas examples where supervised injection rooms, prescribed heroin designed to wean addicts off the substance and some drug decriminalisation brought benefits.

"The laws are really irrelevant to whether people use drugs or not, but it is relevant to whether they come to harm from drugs," he said.

"If you look at where we are in Australia, people use their drugs secretly behind closed doors and in back alleys. The people whose names were read out most likely died on their own because there was no one to help them."

Family Drug Support chief executive Tony Trimingham, who lost a son to drugs in the 1990s, shared his own experiences with the crowd.

He said the pain was "excruciating" at the time but lingered in a different form.

"You would dream they were still with you, then wake up to the nightmare of reality," he said.

"The pain doesn't stop. The pain changes. It's not that intense any more, but it's the lost opportunities; it's the grandchildren we didn't get, it's not seeing them get well."

Former ACT chief minister Kate Carnell, who unveiled the rock during her term in office, was also invited to speak and discussed the changes in attitudes to harm minimisation policy.

As well as remembering and seeking changes to government policy, the day was also for meeting other people who had dealt with the loss of a loved one.

At the end of the ceremony, a man and woman passed. The man smiled and said "see you at the next one".