The aim of treatment is to reduce levels of hepatitis C virus (HCV) to undetectable levels very rapidly. By the end of the treatment course everyone should have undetectable virus levels. Twelve weeks (and sometimes also 24 weeks) after the end of treatment, virus levels will be tested again. If the virus is undetectable at this time, you are considered to be cured of hepatitis C.

If the virus reappears between the end of treatment and the 12-week post-treatment test, this is called viral relapse. Relapses later than 12 weeks after treatment are very rare.