Prepare for your Ultimate Performance Blood Test by following these instructions. Please take your sample before 10am. If you have an unusual sleep pattern (eg shift worker) then take this test within 2 hours of waking. Take this test when any symptoms of short-term illness have settled. Avoid heavy exercise for 48 hours beforehand. Avoid fatty foods for eight hours before your test, you do not need to fast. Take this test two to five days after the start of your period, ideally on day three. It can be taken any time if you do not have periods. Hormonal contraception can affect the results of this test. Taking a break from this and waiting for your periods to restart before your blood test will give more accurate results. Corticosteroid medication can affect this test, ask your doctor whether to stop before testing. If you use hormone gels, pessaries, patches, or tablets, we strongly recommend selecting a venous sample to minimise contamination sometimes seen with finger-prick tests. Otherwise, administer any hormone supplements using gloves, and make sure your fingers have not been in contact with hormone supplements for at least four weeks before taking the test. Hormones can be absorbed deep within the skin even after minimal contact and remain there for weeks despite vigorous handwashing. You should take this test before you take any medication or vitamin/mineral supplements. Do not take biotin supplements for two days before this test, discuss this with your doctor if it is prescribed. Do not take vitamin B12 for two weeks prior to this test. If your B12 is prescribed ask your doctor whether to stop.