Medications · FAQ
Can finasteride affect PSA testing or interact with other medicines?
Short answer
Finasteride can lower prostate-specific antigen, or PSA, which may affect how a prostate blood test is read. Tell anyone ordering a PSA test that you use finasteride, including topical treatment. Share all medicines and supplements with your physician so they can check for overlap, interactions, and other safety concerns.
PSA is a protein measured in blood tests used to help assess prostate health. Finasteride can lower PSA levels. A result that looks normal may need a different interpretation when you take this medicine. Always tell the clinician ordering the test that you use finasteride and when you started it.
Do not stop finasteride just to prepare for a PSA test unless the clinician tells you to. They may use your treatment history and past results to interpret the number. Report topical finasteride use too, since medicine applied to the scalp can enter the bloodstream.
Your physician also needs a full list of your medicines, vitamins, and supplements. Include prostate medicines, other hair-loss products, and any treatment containing finasteride or dutasteride. Taking products with overlapping effects without guidance can add risk.
There is no need to assume that every medicine interacts with finasteride. Still, a pharmacist or physician should review your specific list before you start, stop, or combine treatments.
Sources
Written by the Verra clinical team · Medical review pending
General information, not medical advice. If you're in crisis, call or text 988.