The captopril challenge test (CCT) is a non-invasive medical test that measures the change in renin plasma-levels in response to administration of captopril, an angiotensin converting enzyme inhibitor.

It is not generally considered a useful test for children,[1] and more suitable options are available for adult cases.

Plasma concentration of renin is measured prior to and following the administration of captopril.

[2] CCT in adults is known to have high sensitivity, but a low specificity.

[3] Subtraction angiography is considered a more suitable test for renal artery stenosis in adults.