Comparison
DNA test vs blood test for hormones: which do you need?
Quick answer
A blood test measures your hormone levels today. A DNA test reads the variants you were born with, in genes involved in making, carrying and responding to hormones. They answer different questions, and a DNA test can never replace a blood test for monitoring your health.
- Blood test: changes over time, so it is repeated. It is the test for checking how your body is coping.
- DNA test: never changes, so it is done once. It gives background, not a measurement.
- Neither test can tell you whether anabolic steroids are safe for you.
Your levels, on the day
- Testosterone (total and free), SHBG, oestradiol, LH, FSH
- Haematocrit, liver and kidney function, cholesterol
- Changes with time, medicines and substances
- Repeated: before, during and after any change
- GP (free) or private lab, roughly £60 to £160
Your variants, for life
- Variants in genes such as AR, SHBG, CYP19A1 and UGT2B17
- What research has found about each variant
- Never changes, whatever you take
- Done once, from saliva or a cheek swab
- Private only, roughly £160 to £450
Question by question
| Your question | Blood test | DNA test |
|---|---|---|
| What is my testosterone level? | Yes | No |
| Is my haematocrit, liver or cholesterol OK? | Yes | No |
| Have my levels recovered after stopping? | Yes, by retesting | No |
| Do I carry variants studied in connection with hormones? | No | Yes |
| Is my SHBG partly inherited? | Shows the level, not the cause | Shows some of the variants linked to it |
| Would a doping test read my T/E ratio unusually? | No | The UGT2B17 deletion, if tested, is one known reason |
| Are steroids safe for me? | No | No |
Why genes are only part of the picture
Hormone levels are partly inherited. In UK Biobank, genetic variants explained a meaningful share of the differences in testosterone and SHBG between people, and hundreds of variants were involved, each with a small effect.[1] Age, weight, health, sleep and anything you take change your levels far more from month to month. That is why a DNA result is background, and a blood test is the measurement.
Some genetic differences matter in specific ways. A common deletion of the UGT2B17 gene, for example, changes how much testosterone leaves the body in urine, which affects urine-based doping tests rather than blood levels.[2] Read more in does genetics affect how you respond to steroids?
Using both
- Blood test first, for a baseline of your hormones and blood health. If you use anabolic steroids, keep repeating it: our checklist lists what UK guidance suggests.
- DNA test once, if you want to know which hormone-related variants you carry and what research says about them.
- Talk it through with a GP, a pharmacist or a needle and syringe programme, who can see both.
Questions
Is a DNA test or a blood test better for hormones?
A blood test, if you want to know your hormone levels; that is the only way to measure them. A DNA test answers a different question: which hormone-related variants you were born with. Many people who use a DNA test also have regular blood tests.
Can a DNA test show low testosterone?
No. It can show variants that large studies have linked to slightly higher or lower average testosterone or SHBG, but those variants explain only part of the difference between men. Only a blood test can show your level is low.
Do I need to repeat a DNA test?
No. Your DNA doesn't change, so a genetic result stays the same for life. Blood tests do need repeating, because hormone levels and blood health change.
Which is cheaper?
A single hormone blood test from a UK private lab costs roughly £60 to £160, and NHS blood tests are free when your GP orders them. Private DNA tests for hormone genes cost roughly £160 to £450, but you only need one.
Is a saliva DNA test as accurate as a blood DNA test?
For reading DNA, yes. Saliva contains plenty of DNA from cheek and white blood cells, and laboratories genotype it with accuracy comparable to blood. Saliva can't measure hormone levels reliably for most clinical uses, which is why hormone tests use blood.
Sources
Keep reading
- Tools
Which test do I need?
Four questions that tell you whether a blood test, a genetic test or your GP answers what you want to know.
- Compare
Medichecks vs GeneticEdge
A sports hormone blood test against a hormone-gene DNA test: what each measures and when you'd use both.
- Guides
Blood tests for steroid users
What to test, when, and where in the UK, from published guidance for people who use anabolic steroids.
For information only, not medical advice. GeneticEdge does not recommend or endorse anabolic steroid use, and no genetic test can tell you whether steroids are safe for you. Talk to a GP or pharmacist about your health. Last reviewed 30 October 2026.