HIV test results come back as non-reactive, reactive, or occasionally indeterminate. Non-reactive means no HIV antibodies or antigen were detected, which is a negative result as long as enough time has passed since any possible exposure. Reactive means the screening test detected a signal and a confirmatory test is needed; it is not a diagnosis on its own. Indeterminate means the result was unclear and the test should be repeated. Understanding the window period for the test you took is what makes a non-reactive result meaningful.
Key takeaways
• Non-reactive = negative, if you are past the window period.
• Reactive = needs a confirmatory test; false positives on screening happen.
• Indeterminate = repeat in a few weeks.
• Fourth-generation tests detect HIV about 18 to 45 days after exposure.
The three results
Non-reactive. The test found no HIV antibodies (or antigen, on combination tests). If your last possible exposure was before the window period for that test, this is a negative result. If the exposure was recent, repeat after the window closes.
Reactive. The screening test detected a signal. Screening tests are designed to be very sensitive, so a small share of reactive results are false positives. The lab automatically runs a confirmatory antibody differentiation test and, if needed, an HIV RNA test. Only the confirmatory result establishes a diagnosis.
Indeterminate. The confirmatory test was neither clearly positive nor negative, which can happen very early in infection or for unrelated immune reasons. The next step is an RNA test or a repeat in a few weeks.
Window periods by test type
• HIV RNA (viral load) test: about 10 to 33 days after exposure
• Fourth-generation antigen/antibody test (the standard lab blood test): about 18 to 45 days
• Antibody-only tests, including most rapid and home tests: about 23 to 90 days
A non-reactive result before the window closes cannot rule out infection. Guidelines advise a final test at 45 days for a lab fourth-generation test, or 90 days for antibody-only tests, after the last exposure. The HIV test guide covers the test types.
What to do with each result
Non-reactive, past the window: you are HIV negative as of that exposure. Consider PrEP if you have ongoing risk.
Non-reactive, within the window: repeat at the end of the window. If the exposure was within 72 hours, ask urgently about post-exposure prophylaxis (PEP).
Reactive: wait for the confirmatory result the lab runs automatically. If confirmed, treatment is highly effective, and people on treatment with an undetectable viral load do not transmit HIV sexually. A clinician will connect you to care.
Indeterminate: follow the clinician’s advice on an RNA test or a repeat.
Privacy
HIV results are protected health information. August keeps results in your private dashboard, and a clinician reviews every result and can discuss it with you confidentially.
Testing with August
Order HIV testing, alone or in an STI panel, from the August lab tests catalog. At-home draw or lab visit, results typically the next day for the screening test, confirmatory testing added automatically if needed, clinician review, one all-inclusive price, no membership required. August Care members ($29 a month, cancel anytime) get up to 50% off next-day lab tests, a first clinician consultation included, later consultations at $19, and AI action plans on results.
Frequently asked questions
What does non-reactive mean on an HIV test?
No HIV antibodies or antigen were detected. It is a negative result if enough time has passed since your last possible exposure.
What does reactive mean on an HIV test?
The screening test detected a signal and a confirmatory test is needed. It is not a diagnosis; some reactive screens are false positives.
What does indeterminate mean?
The confirmatory test was unclear. An RNA test or a repeat in a few weeks resolves it.
How soon after exposure can a blood test detect HIV?
A fourth-generation lab test detects most infections by 18 to 45 days; RNA tests from 10 to 33 days.
When is a negative HIV test conclusive?
45 days after the last exposure for a fourth-generation lab test; 90 days for antibody-only tests.
Can a false positive HIV test happen?
On screening, yes, which is why every reactive result is confirmed before any diagnosis.
What if I was exposed in the last 72 hours?
Seek care immediately about PEP, which can prevent infection if started within 72 hours.
Are my HIV results private?
Yes. Results are protected health information, stored in your private dashboard, and discussed only with you.
