Treponemal Syphilis Test
This page explains the treponemal syphilis test, what it measures, and how to arrange it. A treponemal syphilis test is a blood test that looks for antibodies the body makes specifically against Treponema pallidum, the bacterium that causes syphilis. It is usually ordered to confirm a syphilis infection after a first screening test is reactive, or when a person has symptoms or a known exposure.
- Sample type
- blood
- Category
- Sexual Health
- Turnaround
- 1-3 business days
- Price
- $198
- Referral
- Not required
A treponemal syphilis test is a blood test that looks for antibodies the body makes specifically against Treponema pallidum, the bacterium that causes syphilis. It is usually ordered to confirm a syphilis infection after a first screening test is reactive, or when a person has symptoms or a known exposure.
What it measures
- Treponema pallidum antibodies — Proteins made by the immune system in response to the syphilis bacterium.
- Reactive or nonreactive result — A simple positive or negative interpretation of the antibody finding.
- Antibody index or signal-to-cutoff value — A number some labs report to show how strongly the sample reacted.
Who it is for
Any clinician can order this test, including primary care providers, urgent care staff, obstetricians, and sexual health clinic staff. It is commonly offered to people with symptoms, a known exposure, or a reactive initial screening test.
Preparation
No fasting or special preparation is needed. Tell the person drawing your blood about any prior syphilis diagnosis or treatment, because past infection can affect results.
Results and what they mean
Results are reported as reactive or nonreactive, sometimes with a numeric value. A reactive result does not always mean active infection, so a clinician interprets it alongside your history, symptoms, and other tests. This is general information, not medical advice; discuss your results with a qualified clinician.
How to order this test
- Choose the test and place a confidential order online.
- Select a certified collection site and pick a time that suits you.
- Have your specimen collected — most draws take only a few minutes.
- Review results in a secure portal, typically within 1–3 days.
Preparation, hours, and pricing vary by site; confirm details directly with the lab before your visit.
Availability by state
Direct-access online ordering for the treponemal syphilis test is available in most states. It is currently unavailable in 6 states:
Everywhere else you can order confidentially and collect your sample at a certified site. Browse by state →
Frequently asked questions
Does a reactive result mean I have syphilis now?
Not always. A treponemal test can stay reactive for life after a treated infection, so your clinician may order other tests to see whether the infection is current.
How long after exposure can this test be positive?
It can take several weeks after exposure for antibodies to appear, so a test done too early may be nonreactive even if infection is present.
Is this test private?
Yes. Results are kept confidential and shared only with you and the clinicians involved in your care, as allowed by law.
Can other conditions cause a reactive result?
Rarely, some other infections or immune conditions can cause a false reactive result, which is why confirmatory testing may be used.