Friends of Science in Medicine’s Ken Harvey has slammed Chemmart’s myDNA test, which he says “offers more than it can deliver”.

Writing in The Conversation today, Adjunct Associate Professor Harvey, from the School of Public Health and Preventive Medicine at Monash University, says that “some of Chemmart’s claims may be misleading for consumers who lack detailed knowledge of DNA testing and may produce unrealistic expectations of the product’s effectiveness”.

He says that these claims may have breached several provisions of the Therapeutic Goods Advertising Code 2015.

Prof Harvey questions “the effectiveness and clinical utility” of pharmacogenetic testing, which he says is still uncertain.

“A ‘normal’ PGx test doesn’t mean you’re not at risk of drug-related side-effects or of not responding to a drug,” he writes. “Current tests only capture known variants of known genes.

“And even if the test shows gene variants that impact on a certain drug’s metabolism, this is only one of many patient characteristics and factors that influence how they respond to drugs. Others include interactions with other drugs, allergies, and kidney and liver function.”

He says that Chemmart’s claim that “myDNA is a genetic test that identifies which medications will work best for you” overstates the role and value of the test.

“It has limited applicability only to certain drugs in particular situations,” he writes.

“We do not believe the test is ‘particularly relevant’ to those who ‘take multiple medications, have children on prescribed medication’, or ‘are pregnant or planning pregnancy’ because of the extremely limited applicability of the test to these patient groups.

“We also have problems with the claim that ‘the myDNA test covers 50% of the most commonly prescribed medications’.”