Why do some UK clinics ask people to wait 3 months before an HIV test?

No UK clinic should ask you to wait for three months before testing.

UK guidelines say you can be tested 3 to 4 weeks after an exposure.

Ask if your clinic uses 4th generation tests. If so, you can test after four weeks, and confirm this with a second test after three months.

If your clinic doesn’t use 4th generation tests ask why not, and where you can get this test.

Please call i-Base if you want us to help.

BASHH statement on the window period

  • HIV testing using the latest (4th generation) tests are recommended in the BHIVA/BASHH/BIS UK guidelines for HIV testing (2008).
  • These assays test for HIV antibodies and p24 antigen simultaneously. They will detect the great majority of individuals who have been infected with HIV at one month (4 weeks) after specific exposure.
  • Patients attending for HIV testing who identify a specific risk occurring more that 4 weeks previously, should not be made to wait 3 months (12 weeks) before HIV testing.
  • They should be offered a 4th generation laboratory HIV test and advised that a negative result at 4 weeks post exposure is very reassuring/highly likely to exclude HIV infection.
  • An additional HIV test should be offered to all persons at 3 months (12 weeks) to definitively exclude HIV infection. Patients at lower risk may opt to wait until 3 months to avoid the need for HIV testing twice.

Ref: British Association on Sexual Health and HIV (BASHH), March 2010.

Last updated: 1 December 2019.