What is the Genetic Medicines Test Service and how does it work?
The Genetic Medicines Test is a convenient at-home test that looks for gene variations affecting how your body processes certain medications. Your results can help your doctor determine whether you metabolise a medication quickly, slowly, or at a typical rate. If you're found to be a fast or slow metaboliser, your doctor may adjust your dosage to improve effectiveness or reduce side effects. This is the first private service of its kind in the UK and is also available to users in the US.
Give me an example of why this service may suit me?
In psychiatry, choosing the right antidepressant or antipsychotic often involves trial and error. These medications can have limited effectiveness and may cause unwanted side effects, meaning your treatment might not work as well as it should.
The Genetic Medicines Test helps your doctor personalise your treatment by adjusting the medication or dose based on your genetic makeup, improving both safety, effectiveness and treatment outcomes.
The infographic below shows how your genes can influence how you process certain medications.
What genes do you test?
We currently offer two gene panel tests to help you understand how your body may respond to certain medications. Our laboratory screens for genetic variations with a validated sensitivity of over 99%.
The two gene panels we test are:
CYP2C19
CYP2D6
These enzymes play a key role in processing more than 30% of commonly prescribed medications, including many antidepressants and antipsychotics.
What is CYP2C19?
CYP2C19 is an enzyme involved in breaking down 5–10% of commonly prescribed medications. It is controlled by the CYP2C19 gene, and variations in this gene can affect how well the enzyme works.
Around 3–6% of people of European and African ancestry, and 13–23% of Asian populations, have a slower-acting form of the enzyme, making them poor metabolisers.
Your rate of drug metabolism is important; it influences how your body processes medication.
Fast metabolisers break down drugs too quickly, which can reduce effectiveness.
Slow metabolisers process drugs too slowly, increasing the risk of side effects or toxicity.
By testing for CYP2C19 gene variants, we can determine whether you are a fast, normal, or slow metaboliser. This information helps your doctor decide whether the standard dose of a medication is appropriate, or if it needs to be adjusted or replaced.
This is a personalised approach to prescribing, ensuring that the right medication and dosage are selected based on your unique genetic profile.
What is CYP2D6?
CYP2D6 is an important enzyme responsible for metabolising about 25% of all prescription medications. This enzyme is regulated by the CYP2D6 gene, and genetic differences can significantly affect how well it functions.
Your metabolism rate influences how your body responds to medication:
Fast metabolisers break down drugs too quickly, which may reduce their effectiveness.
Slow metabolisers process drugs more slowly, increasing the risk of side effects or toxicity at standard doses.
By testing for CYP2D6 gene variants, we can identify whether you are a fast, normal, or slow metaboliser. This insight helps your doctor determine if the usual dosage is appropriate for you, or whether it needs to be adjusted or changed altogether.
This is a personalised approach to prescribing, ensuring that the right medication and dosage are selected based on your unique genetic profile.
What advantages does the Genetic Medicines Test offer me?
Limiting adverse effects
If there is a change in your DNA that causes the gene to produce fewer proteins, then your body could break some medications down more slowly, leading to a higher chance of side effects as the medications ‘builds up’.
Therapeutic Efficacy
If your body is producing too many of these proteins then you might work through medications too quickly to really get a benefit from them.
Genetic Medicines Test results are lifelong results
These results are lifelong results. However, as tests change and new genes are researched, you may be asked or want to perform further Genetic Medicines Tests in the future. The laboratory reference sheet at the end of the report will be your best resource for determining if other testing could provide benefits.
Benefit outside of the initially ordered indication
Some genes, like CYP2D6 and CYP2C19, can provide information on multiple drug classes. For instance, these same genes can be involved in antidepressant medications, opioid pain medications, antipsychotics, proton pump inhibitors and nerve pain medications.
What are the limitations of the Genetic Medicines Test Service that I need to be aware of?
Not All Medications Are Covered
The Genetic Medicines Test service is designed to identify specific gene-drug interactions, primarily involving the CYP2D6 and CYP2C19 enzymes. These enzymes play a key role in processing a wide range of medications, especially antidepressants, antipsychotics, and other frequently prescribed drugs. However, many medications are broken down through other biological pathways. As a result, not all medications you use will be covered by this test. You can check if your medication could be influenced by the gene test using our eligibility checker.
Negative Predictive Test (NPT)
It is possible that the results of the testing will not help you and your physician in managing your care. Even if we narrow down the choices based on the results, it doesn’t guarantee that those medicines will work for you. There may still be some trial and error.
Only one part of the medication selection process
Keep in mind that genetics is one of many factors taken into consideration when selecting a medication. Depending on the medication, drug-drug interactions, kidney and liver function, age, weight and diet, just to name a few, can also play a role.
May not catch rare variations
Genetic Medicine testing does not evaluate the entire gene. We look for changes that are known to affect how you respond to a drug. You may have a change in your genes that we are not looking for. If that happens, you could have a normal test result and still have changes in how you respond to medications. As more research is completed, different tests may be available in the future.
Genes with limited evidence
The Genetic Medicines Test we use gives us the results for many genes. Our clinicians will only make recommendations for genes that have enough research to help us select medications. The genes we do not talk about today may become important in the future as
Are there any concerns or risks I need to be aware of?
Genetic discrimination and protections
If you are concerned about the risks of genetic testing with respect to insurance coverage, we refer you to the UK Code on Genetic Testing and Insurance. This code bars employers and health insurance from discrimination based on genetic testing.
Disease risk
This test does not look at disease risk or other health factors. Genetic Medicine testing only looks at genes and their relation to the response to certain medications.
What is the evidence for Genetic Medicines Tests?
Our testing is based on CPIC (Clinical Pharmacogenetics Implementation Consortium) evidence. The medications we offer testing on through the service have a PharmGKB Clinical Annotation Level of evidence of 1A, 1B, 2A and 2B and a CPIC level status of ‘final’.
CPIC level A and level B gene/drug pairs have sufficient evidence for at least one prescribing action to be recommended, and only those gene/drug pairs that have been the subject of sufficient in-depth review of evidence are given the CPIC assignment level of ‘final’.
Is this a safe service?
For UK users, our German laboratory complies with the fundamental guidelines set out in the quality assurance for clinical laboratory testing by the German Medical Association (Bundesarztekammer).
Furthermore, the requirements of DIN EN ISO 15189:2014 are all met and are established in an integrated quality management system based on the certification according to DIN EN ISO 9001:2015 and the requirements of the Rili-BAK (2019).
In addition, all consumables used for sample collection are procured in the UK and certified with conformance standards bodies.
For US users, our American laboratory is CLIA-certified and registered with the Pennsylvania Department of Health.
Both the UK and US services utilise Clinical Decision Support (CDS) software based on the evidence base of the Clinical Pharmacogenetics Implementation Consortium (CPIC).
Is the service available in the United States and the United Kingdom?
Yes. This service is available in the United Kingdom and the United States.
Do I need to pay for this service?
Yes, this is currently a private service. However, in the UK, this may change and may be funded by the NHS, in the future. In the US, it may be possible it is covered by insurance, but this depends on your health plan.
I have been recommended two tests covering CYP2D6 and CYP2C19, do I need both?
Yes. Your medication may be sensitive to both CYP2D6 and CYP2C19 therefore, we recommend you have both panels tested.
For example, CYP2D6 and CYP2C19 are two clinically relevant genes that can influence how your body metabolises antidepressants.
If you only had one gene panel tested, this would not give you conclusive information about how your body processes the medication you take because the other panel’s influence would be unknown.
How do I use the Genetic Medicines Test Service?
Navigate to the Genetic Medicines Test Service Card which can be found in the ‘Private Care’ section of the account homepage.
Choose ‘Check Eligibility’ from the Options Menu on the Genetic Medicines Test Service Card.
Use the AI Chat Bot to check if your medication is influenced by your genes.
Or, if you have provided us with access to your medication records, we will run an AI eligibility check to see if you qualify. If you do, we will send you a notification.
If you qualify, you can click ‘View Test’ to learn more about the test, or alternatively ‘Add to Cart’.
Follow the steps below to complete your purchase:
What Happens Next:
Home Test Kit Delivery
Your Genetic Medicines Test Kit will be delivered to your home or preferred address.
Collect Your Sample
Follow the step-by-step instructions included in the kit to collect your sample.The following instructions will be included:
Return Your Sample
Use the prepaid return packaging provided to send your sample back to our laboratory.
Processing & Notification
Once your sample has been analysed, you’ll receive a notification letting you know your results are ready.
Book Your Consultation
Schedule an appointment with one of our licensed genetics clinicians to review your results.
Follow the instructions below to book:
View Your Results
After your consultation, your results will be available in the ‘Reports & Letters’ section on the account homepage.
How do I return the sample to your laboratory?
We supply you with a return system package. Use this to send back the sample. Samples are fully tracked and can be posted from any Royal Mail post box, for UK customers, or USPS, for US customers.
How long does it take to get the test results back?
Test results can take up to 10 working days to process from the day we receive your sample back.
What happens during the consultation?
Here’s how the virtual consultation will generally go:
Introduction & Verification
The clinician will begin by introducing themselves and confirming your identity to ensure privacy and confidentiality. The clinician will also explain what the Genetic Medicines Test is designed to do, that it identifies genetic variations that can affect how the patient metabolises or responds to specific medications.
Review of Test Results
They will walk you through your test results, in clear, non-technical language, explaining what the results me for you in relation to:
Metaboliser status (e.g., poor, intermediate, normal, rapid, or ultra-rapid)
Which genes were tested (e.g., CYP2D6, CYP2C19)
How your gene variants may affect your response to your medications
3. Personalised Interpretation & Recommendations
During your consultation, the clinician will review your Genetic Medicines Test results and explain what they mean in relation to the medications you're currently taking. If the results suggest that a medication or dosage may not be suitable for you, the clinician may recommend that your doctor reviews your prescription.
In this case, a referral letter, including your test results, will be sent to your doctor. If the test results indicate that your current medications are unaffected by your genetic profile, the consultation will simply conclude without the need for changes or further action.
4. Answering Your Questions
You’ll have time to ask questions or discuss any concerns. The goal is to make sure you understand how your gene/medication status may affect your treatment outcomes and be provided with the next steps clearly.
5. Next Steps & Support
After the consultation, you’ll receive a notification summarising the key outcomes of your consultation. This summary will include whether a referral letter to your GP was made.
If a referral was issued, a copy of the letter will be available in the ‘Reports & Letters’ section of the account homepage.
Your test results will also be unlocked, allowing you to view, download, and share them with any other healthcare provider as needed.
Are my results confidential?
Yes, we follow strict General Data Protection Regulations (GDPR) which came into force in May 2018. This places legal requirements on ourselves to ensure your personal data is managed securely with utmost confidentiality. Records are maintained of the processing that is carried out and reported when breaches of the regulation do occur. Our platform is also HIPAA compliant which means we are able to handle PHI (Personal Health Information) securely.