Raw research findings for this medication. Mostly single studies, not curated or confirmed robust.
Losartan is an angiotensin II receptor blocker (ARB): it stops the hormone angiotensin II from narrowing blood vessels and making the body hold salt. It is used for high blood pressure, to protect the kidneys in type 2 diabetes, and in heart failure. It is sold as Cozaar, among other names, and with hydrochlorothiazide as Hyzaar.
The liver enzyme CYP2C9 turns losartan into its more potent active form (E-3174). People with reduced-function CYP2C9 versions such as *3 form less of it, and some studies found a smaller drop in blood pressure in them. Studies have also looked at genes of the renin-angiotensin system, such as the receptor gene AGTR1 and ACE, with weaker evidence. There is no CPIC or DPWG guideline.
Every published finding on gene variants and Losartan. Upload your DNA file to see which of these rows apply to you.
PharmGKB weighs all studies of a variant and rates how strong the evidence is, from 1A (strongest) to 4.
CYP2C9 CYP2C9*1, CYP2C9*2, CYP2C9*3, CYP2C9*5, CYP2C9*6, CYP2C9*8, CYP2C9*13, CYP2C9*59, CYP2C9*62: Level 3. Metabolism/PK. 6.
CYP2C9 rs1934969: Level 3. Other. 2.
CYP2C9 rs1057910: Level 3. Efficacy. 2.
ABCB1 rs1045642: Level 3. Efficacy: Hypertension. 1.
Studies of how quickly the body processes this medication.
Studies of how well it worked in people carrying a variant.
Studies that do not fall into the groups above.
Study findings and evidence levels: PharmGKB (CC BY-SA 4.0). Guidelines: CPIC and DPWG, as bundled in PharmCAT. Most studies were done mainly in people of European ancestry.
More drugs from the same category
Not a prescribing recommendation. This page is educational information about pharmacogenomic research and clinical guidelines - it is not medical or dosing advice, and not a prediction of how any medication will work for you. Never start, stop, or change a medication or dose based on it; talk to your doctor or pharmacist, who can order clinical-grade testing if appropriate.
Content updated September 2026.
ReadYourDNA provides educational interpretation of DNA data you already have. It is not diagnostic, not a substitute for professional medical advice, diagnosis, or treatment, and is not intended to diagnose, treat, cure, or prevent any disease. Talk to a clinician before acting on any result.
Raw DNA Data Reports for 23andMe & AncestryDNA · About ReadYourDNA · FAQ · Methodology & Science · Pricing · Support and complaints · Legal & Contact · Health Traits · Pharmacogenomics · Carrier Status · Variant Explorer · The Human Karyotype · Privacy Policy · Terms of Service · Accessibility · Consumer Health Data Privacy · Your Privacy Choices · Editorial Standards · Your Data, Checkable · Sample Report · ReadYourDNA and Promethease compared · What is inside a 23andMe raw data file · What is inside an AncestryDNA raw data file · What a chatbot can and cannot do with your raw DNA file · Where a raw DNA file can still be uploaded in 2026
Written, maintained and operated by Martin Pechhacker, sole proprietor, Vienna, Austria. Trade register GISA 40064420. support@readyourdna.com