There are some medications and supplements that can affect the reliability of blood results.

Here are some examples of things that might affect certain results:

We advise completing the course and waiting until you feel recovered before collecting your sample.

We recommending not taking biotin supplements at least 48 hours before collecting a blood sample.

Your results will only show what your hormone levels are from hormonal contraception — the insights might be less useful. This includes the oral contraceptive pill, implant, ring, injection, and hormone replacement therapy.

If you just stopped contraception, wait three months before doing this test — this allows time for your natural cycle to return. If you were using the contraceptive injection, we recommended waiting until your cycle returns to what it was before starting — this can take up to a year.

If you use an oestrogen or testosterone cream / gel, always use a glove when applying it. Contact with your fingers could affect your finger-prick oestrogen or testosterone result.

If you’ve been prescribed medication by a healthcare professional, always check with them if you’re thinking of stopping it before doing a blood test. They can advise if it’s safe to stop, and how to restart your medication if needed.

If you’ve been prescribed any medications or supplements, check with a health professional before stopping them.

Add any medications or supplements you’re taking to your health profile. The GP reporting on your results can take this into account and let you know whether it might have affected your results.

Looking for something else? Perhaps one of these articles might help:
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​How do I get my results?
​What are your women's health test packages?

When should I take my test?