The painkillers manufacturer, Reckitt Benckiser, settled the class action over its specific pain range at the federal court in Sydney last month.
According to the terms of that settlement, which was reached on behalf of claimants by law firm Bannister Law, each person who claimed to have bought the relevant painkillers between 2011 and 2015 would receive a set amount in compensation per packet.
If the settlement is under-subscribed; that is, if the total amount claimed at the end of the settlement period is less than whatever funds remain once the third-party settlement administrator has been paid, then the leftover funds are returned to Reckitt Benckiser.
But if there are too many claimants for everyone to be paid the set fee, the funds paid to individual claimants will be adjusted at a pro rata rate.
Say only $2m is claimed out of the $3.5m, and its $500,000 for the administrator and there is still $1m there, that money will go back to the respondent, Bannister Law lawyer Diane Chapman, who conducted the class action, told Guardian Australia.
But if there are 10 million Australians who applied for the funds it may only be a one-off payment of not a very large amount.
Chapman said that scenario was not out of the question.
Any person who bought one of the designated products between 2011 and 2015 is eligible to join the class action by applying online and then filling out a statutory declaration, which will be emailed out.
No proof of purchase is required, but those who claim to have spent more than $200 on the painkillers may be audited to determine both the veracity of their claim and the size of their settlement.
As of 31 July, the date the settlement was agreed, the class action had 1,700 members. A spokesman for Bannister Law said that number was growing daily.
The final number of members will not be determined until four months after the settlement hearing, which will be before the federal court in Sydney on 20 September.
Nurofen conceded to the court that all products contained exactly the same active ingredient, 342mg of ibuprofen lysine, and none were more or less effective than any of the others at alleviating a specific source of pain.
The products were more expensive than standard Nurofen products, which used a different ibuprofen formula.
Chapman said some consumers, particularly those with chronic pain issues, had spent several thousand dollars on the products.
There is a real social justice issue in this case, Chapman said. Theres a lot of people out there that would like to know that Reckitt Benckiser has done the wrong thing and consumers have got some recompense.
Reckitt Benckiser did not respond to a request for comment.