STD Testing Window Periods

How Long to Wait Before You Test

On This Page: Window Periods by Test | Why Windows Differ | Known Exposure Date | Unknown Exposure Date | Retesting After Treatment | Where to Get Tested | FAQ

There is no single number that works for every test. How long you should wait depends on which infection you are testing for, and on what the test actually looks for in your sample.

The gap between exposure and the point a test can find an infection is called the window period. Across a full panel, those windows run from about one day to about nine weeks.

Here is the short version. Tests that look for the bacteria or virus itself, using a urine sample, work fastest. Chlamydia can show up in 1 to 5 days and gonorrhea in 2 to 6. Tests that look for your immune response take longer, because your body has to react first. Hepatitis C is the slowest at 8 to 9 weeks.

By three weeks after an exposure, a full panel covers most of what it tests for. Herpes and hepatitis C are still too early, and hepatitis A may be. And no lab claims 100% accuracy on any test, so a negative result taken inside the window is a partial answer rather than a final one.

Window periods for every test on an STD panel

How to read this table. Find your test in the first column, then look at Wait at least. That is the earliest point the test can reliably find an infection, so testing before that date risks a negative result you cannot trust. A few tests also show a Conclusive at date. That is the later point when a negative result is treated as settled, so if you tested early and came back negative, that is the date to test again.

Most rows show one number rather than two. A second number appears only where the lab documents a firmer later point, which is the case for both HIV tests and for trichomoniasis. For every other test on the panel, work from the Wait at least column.

No lab claims 100% accuracy on any STD test. The dates above are the points where a test becomes reliable, not the points where it becomes perfect, which is why the retest advice further down matters.

Why some tests work in days and others take weeks

The timing comes down to what each test is looking for.

The three fastest tests look for the infection itself in a urine sample, so as soon as there is enough of it to find, the test finds it.

The slower tests look for your immune response. That response does not exist on day one. It takes weeks to build. Hepatitis C sits at the end of the list because the test is waiting on an antibody your body has not made yet.

That difference matters again when you read your result. Hepatitis A looks for an IgM antibody, which points to a current infection. Hepatitis C and both herpes tests look for IgG, which can stay in your blood for life. So an IgG result can come back positive for something your body handled years ago. If you want the full picture on how results are worded, see how to read your STD test results.

It is also why the HIV RNA early detection test is useful from nine days when the standard HIV test is not useful until three weeks. One looks for the virus itself. The other looks for a piece of the virus plus your body’s reaction to it.

When to test if you know the date of your exposure

Count forward from the longest window you care about, not the shortest.

Less than 7 days ago. A urine test for chlamydia, gonorrhea and trichomoniasis can already tell you something useful. Nothing blood based can yet. If HIV is your main worry, the HIV RNA test comes into range at nine days.

One to two weeks ago. The urine tests are solid now, and Mycoplasma genitalium is in range. The blood tests are still too early.

Three weeks ago. This is the point where a full panel starts to make the most sense, because the HIV 4th generation test, hepatitis B and syphilis all come into range together. Hepatitis A may or may not.

Six weeks ago. Herpes, hepatitis A and syphilis are all comfortably in range.

Nine weeks ago. Everything on the panel, hepatitis C included.

If a negative result comes back and you tested inside the window for the thing you were worried about, book the retest. Treat that result as a first look, not a final one.

When to test if you don’t know when you were exposed

Worried you were exposed but not sure when? That is a common situation, and a table cannot answer it. Two rules cover nearly all of it.

Test now, then pick a date to test again. Testing now covers anything you picked up long enough ago to show up, which is most of what a panel looks for. What it cannot do is rule out something from the last few days.

Choose the retest date from the longest window that matters to you. If one infection is your main concern, use the window for that test. If you want a clear answer across the board, nine weeks after the last possible exposure covers every test on the panel, hepatitis C included.

Nine weeks can feel like a long wait. Test now anyway, because a positive result found today is a result you can act on today, and treatment can start as soon as you have it.

When to test again after treatment

Two questions get mixed up here. The first is when a test can find an infection in the first place. The second is when to test again after you have been treated. They have different answers.

Do not test again the moment you finish treatment. Genetic material from dead bacteria can still show up on a urine test, so a test taken too soon can report an infection you have already cleared. For chlamydia, the CDC advises against a test to confirm the cure until at least four weeks after you finish treatment.

For chlamydia, gonorrhea and trichomoniasis, test again about three months later. That retest is about catching a new infection, not about whether your treatment worked, and the CDC recommends it whether or not you believe your partner was treated.

For gonorrhea, a test to confirm the cure is not usually needed. The CDC does not recommend one for a standard urogenital infection treated with a standard regimen.

For Mycoplasma genitalium, a test to confirm the cure is not recommended either if you had no symptoms and were treated with a standard regimen. If symptoms stick around, that is a reason to speak to a clinician rather than to retest on a schedule.

Where you go to get tested

You order online, visit a lab, and give a sample. The labs are Quest Diagnostics and Labcorp patient service centers, and there are over 4,500 of them. These are the same centers your own doctor would send you to for bloodwork, and they are run by those labs rather than by us.

You do not need an appointment. Once your order is placed you can walk into a center during business hours, and if you would rather have a set time you can call the lab and arrange one. Most visits take under five minutes.

You can find a testing center near you or read how the whole process works.

Frequently asked questions

Can I test the day after a possible exposure?
You can, and for chlamydia and gonorrhea it may already tell you something, since those windows start at one and two days. For anything blood based it is too early, and a negative result would not mean much. If you have already tested very early, the useful next step is booking the retest.

What is the shortest window on the panel?
Chlamydia, at 1 to 5 days. It is a urine test that looks for the bacteria’s genetic material instead of your immune response, which is why it is quick.

What is the longest window on the panel?
Hepatitis C, at 8 to 9 weeks. It is an antibody test, so it depends on your body having responded first.

How long after exposure is an HIV test accurate?
The standard HIV test on our panels is a 4th generation test. It looks for a piece of the virus plus your antibody response, and it becomes reliable at about three weeks, with 12 weeks as the point the result is treated as settled. The HIV RNA early detection test looks for the virus itself and becomes reliable at about nine days, with 28 days as its settled point.

Does a negative result inside the window mean I am in the clear?
No. Test again after the window has passed for the test you took. This is the most common reason a negative result turns out to have been wrong.

Why do two tests for the same infection have different waits?
Because they look for different things. A test for the organism’s genetic material can work as soon as there is enough of it to find. A test for your antibodies cannot work until your body has made them.

Is any STD test 100% accurate?
No, and no lab claims otherwise. Accuracy varies by test, and that is the whole reason retesting exists.

Do I need an appointment?
No. After you place your order you can visit the lab any time during business hours. If you are pressed for time, you can call the lab and make an appointment.

If I test positive, what happens next?
Positive results come with the option of a phone consultation, where a clinician explains the result and can discuss treatment. See doctor consultation for how that works.