Hi James I know how stressful this can be. Some people generate antibodies from three weeks post exposure, but most do not. So your test result at 4.5 weeks, whilst encouraging, can't be relied on. There is a lot of information on the internet, unfortunately not all of it is reliable. There are laboratory tests available in the UK that can detect HIV infections as early as 4 weeks post exposure. These tests require taking blood from a vein and sending the sample off to a lab. The results can then take anywhere between 4 hours and 4 days to be returned to you, depending on where you get the test done. I'm really sorry that this has been as stressful as it has, but taking steps to know your HIV status is really important. Kind regards Gary Carpenter BioSure (UK) Limited

Thanks Gary. so I guess the 4.5 week test result is no good as this would not turn positive until at least six weeks. I will have to get another test - I misunderstood some internet website which said window period was usually four weeks. This is very stressful. Many thanks for your help

Hi James Thanks for the question. The test is a 2nd generation HIV test. The generation of the test actually comes form the method of construction of the test, the "window period" is a function of the generation. The BioSure HIV Self Test detects antibodies to HIV from the class known as IgG. IgG antibodies are made as the second wave of the bodies response to an HIV infection. Most people will have the first wave of antibodies, IgM, at around 4 weeks, with the second wave about 14 days later. But this does not apply to everyone. A very small number of people, approx. 2%, do not generate antibodies until 3 months after infection. So, a negative HIV test is always encouraging but at 4.5 weeks should not be relied on. We would recommend that you retest at 3 months post exposure, either through an additional self test or through a clinic. I hope that this helps. If you have any questions, please don't hesitate to contact me again. Kind regards Gary Carpenter BioSure (UK) Limited