The impetus for such a move was driven by the high costs of wholesale drugs and medicines at the time, and Leete and Church set about manufacturing their own products for sale exclusively by members of the association.

Established as a company to be funded by member subscriptions, initial interest from pharmacists was lukewarm, however Leete and Church persisted with their manufacturing plans.

In 2017, partly in response to Australian Government changes pharmacists’ payments under the Pharmaceutical Benefits Scheme, Sigma diversified further, acquiring Medication Packaging Systems (MPS), Australia's largest provider of dose administration services to the aged care sector and community pharmacy patients.

During the 2020 COVID-19 pandemic, Sigma announced that it had sold the land and buildings of its distribution centres in Queensland and New South Wales, under an agreement to lease the facilities back from the new owners for an initial term of 15 years.

[8] The following year, Sigma launched a bid for Australian Pharmaceutical Industries, which owned a number of rival retail pharmacy brands including Priceline, Pharmacist Advice and Soul Pattinson Chemists.

[13] The Group reported net profit after tax (NPAT) attributable to owners of the company for the year ended 31 January 2021 of $59,761,000 which was up $72,091,000 from the prior period ($12,330,000 loss).