Pharmacogenomic testing, also called PGx testing, looks at how specific changes in your genes affect the way your body responds to certain medicines.
Genes are pieces of DNA that give instructions to make your body look and work the way it does. Specific changes in your genes can affect how slow or fast your body processes—or metabolizes—medicines.
If your body processes a medicine slower than expected, you may have more side effects. This is because too much of the medicine can build up in your body.
If your body processes a medicine faster than expected, the medicine may not work well for you, because your body gets rid of it too fast for it to work properly.
Some changes in your genes can also put you at higher risk of having certain serious side effects from some medicines.
To learn more about genetics, including genes, DNA, and other kinds of genetic testing, go to
Understanding genetics.
What testing can tell you
Pharmacogenomic testing tells you which changes in your genes you have and which medicines they may affect. This information can help your healthcare providers choose medicines and doses for you.
It’s common for the tests results to show that your body processes medicines as expected. But some test results may show you could benefit from using different doses or avoiding certain medicines.
Having these test results could be helpful for the healthcare you are receiving now and in the future.
Always speak to your healthcare provider before making any changes to or decisions about your medicines.
How testing works
There are 3 steps to pharmacogenomic testing:
- Collect a sample: A sample of your DNA is collected, typically using a cheek swab.
- Analyze the sample: The sample is analyzed in a lab to show the changes in your genes that may affect how your body processes different medicines.
- Interpret the results: A pharmacist and the healthcare provider who ordered the test review the results. They use the results to make decisions about medicines that will be prescribed for you.
What results look like
Pharmacogenetic testing done by Alberta Precision Laboratories uses a classification system called star alleles. A star allele is a specific version of a gene. It is identified with a star (*) and a number, like *1 or *2.
You inherit one copy of each gene from each parent, so your test report will show two star alleles for each gene.
The combination of these two star alleles helps predict how quickly or slowly your body processes certain medicines.
Your test report will:
- show your two star alleles for each gene tested
- explain what your test results mean
- have recommendations that can help your healthcare provider choose medicines and doses of medicines for you
The report is based on guidelines from:
- the Clinical Pharmacogenetics Implementation Consortium
- the Dutch Pharmacogenetics Working Group
- the U.S. Food and Drug Administration
How to get tested
Make an appointment with your healthcare provider to talk about pharmacogenetic testing and if it’s right for you.
You may be able to get testing through a referral in Alberta. You can also pay for private testing, which is available across Canada.
Learn more
Research continues to learn about how changes in our genes affect the medicines we use.
For more information about pharmacogenomic testing, go to
ClinPGx: What is pharmacogenomics?
