This page is general health information, not medical advice. It cannot tell you whether you have an infection. A clinician can, and the testing options on this site are a good place to start.

Mycoplasma genitalium is a bacterial sexually transmitted infection that many people have never heard of. It is rarely named on a clinic menu, and it is not part of the routine panel most people get. That gap can be confusing when symptoms keep coming back after treatment for something else.

This guide covers what the organism is, what research suggests about it, why testing works differently, and how to ask about it in Houston. The focus is on the science and on practical next steps, not on worry.

What mycoplasma genitalium is

Mycoplasma genitalium, often shortened to M. genitalium or MG, is a very small bacterium. The CDC STI Treatment Guidelines (2021) list it as a cause of urethritis in men. The guidelines also link it to cervicitis and, in some cases, pelvic inflammatory disease in women.

It spreads through sexual contact. That includes vaginal, anal and oral sex, and the CDC describes it as an infection that can affect people of any gender or orientation.

Because it is a bacterium, it is curable with the right treatment from a clinician. The challenge is that treatment is not as simple as it is for some other bacterial infections, as explained below.

How the organism is built, and why that matters

This is the part that works like a composition breakdown. Most bacteria are wrapped in a rigid cell wall. M. genitalium is among the smallest known bacteria that can reproduce on its own, and it has no cell wall at all.

Research suggests this structure explains several practical facts:

No cell wall means some drug families do not work. Many common antibiotics act by attacking the cell wall. Those drugs have nothing to act on here, so a clinician has to choose from other classes.
It is hard to grow in a lab. Researchers have found it very slow and difficult to culture. That is why modern detection relies on molecular tests rather than growing the bacteria.
It has a very small genome. Research suggests it depends heavily on its host for nutrients, and that it can change certain genes under drug pressure.

That last point leads directly to the biggest issue clinicians discuss with M. genitalium: antibiotic resistance.

Mycoplasma genitalium symptoms

Mycoplasma genitalium symptoms overlap with those of chlamydia and gonorrhea, which is part of why it is easy to miss. According to the CDC, the infection can show up in a few ways.

In people with a penis

Burning or discomfort when urinating
Discharge from the urethra
Symptoms that clear and return, or that linger after treatment for another infection

In people with a cervix

Unusual vaginal discharge
Bleeding after sex or between periods
Pelvic or lower abdominal pain, which a clinician would want to evaluate promptly

Many people have no symptoms at all. The same symptoms can come from many other causes, so symptoms alone cannot say what is going on. Only a clinician and a lab test can sort that out.

If you are also reading about similar infections, our guide on chlamydia symptoms, testing and treatment in Houston covers the one most often checked first.

When CDC recommends testing

This is where M. genitalium differs from most other STIs. The CDC STI Treatment Guidelines (2021) do not recommend testing people who have no symptoms, and they do not recommend routine screening for the general population. The reasons include the lack of evidence that finding it in someone without symptoms improves health, and concern that treating more people could add to resistance.

The CDC does point to specific situations where testing makes sense:

Persistent or recurrent urethritis. This means urethral symptoms that continue or come back after initial treatment.
Persistent or recurrent cervicitis. This is the same pattern in someone with cervical symptoms.
Some cases of pelvic inflammatory disease. The CDC says testing can be considered.

The guidelines also say clinicians may consider testing sex partners of a person who has been diagnosed. Your own clinician is the right person to decide what applies to you. Nothing here tells you whether you should or should not be tested.

Why it is not on standard panels

A routine STI panel usually covers chlamydia, gonorrhea, syphilis and HIV, and sometimes trichomoniasis or hepatitis. M. genitalium is generally not included, for a few reasons that research and the CDC describe:

Screening is not recommended. Since the CDC does not advise testing without symptoms, labs and clinics have little reason to bundle it into a default panel.
It needs a specific molecular test. The CDC describes nucleic acid amplification tests (NAATs) as the way to detect it. FDA-cleared tests exist, but they are a separate order from the usual panel.
Access varies. Not every clinic or lab offers the test.

The CDC does not publish a window period for M. genitalium the way it does for HIV or syphilis. If you have had a recent exposure, a clinician can tell you what timing makes sense for the test they use.

Resistance-guided treatment

Research suggests that M. genitalium has developed resistance to some of the antibiotics clinicians have long used. The CDC STI Treatment Guidelines (2021) report that resistance to the macrolide class is common and that a drug family often used for other bacterial infections, doxycycline, does not reliably clear this one on its own.

Because of this, the CDC recommends resistance-guided therapy when it is available. In plain terms, the lab checks the sample for genetic markers linked to macrolide resistance. A clinician then uses that result to choose which medicine to prescribe.

Some points worth knowing:

Treatment is something only a clinician prescribes. This page does not name amounts or schedules, and you should not take leftover or borrowed medicine.
Completing the full course a clinician gives you matters, because partial courses can add to resistance.
A follow-up visit may be suggested if symptoms do not improve.
Partners may need evaluation too, so that the infection is not passed back and forth.

Doxy-PEP, the doxycycline option for some people after sex that the CDC addressed in its 2024 guidance, is aimed at certain bacterial STIs. It is a topic to raise with a clinician, who can explain what it does and does not cover.

Safety profile and quality of testing

Instead of ingredients, the safety questions here concern the test and the treatment.

The test itself

The sample is usually a urine sample, a vaginal swab or another swab, depending on your anatomy and symptoms. It is low risk. The main quality point is that the CDC describes FDA-cleared NAATs as the appropriate type of test. If a test is not clear about what it detects, ask the clinic what method it uses and whether it checks for resistance markers.

Treatment

Medicines carry their own cautions, such as allergies, other medicines you take, and pregnancy. A clinician needs your full health history to choose safely. Tell them about any past reactions to antibiotics.

Reading a result

A positive or negative result only describes the sample that was tested. Ask the clinic what the result means for you, and whether follow-up testing is advised.

Where to ask about testing in Houston

None of the Houston clinic pages we reviewed list M. genitalium testing by name. That does not mean it is unavailable. It means you should ask directly before you go. A good question is: "Do you test for mycoplasma genitalium, and does the test include resistance markers?"

Here are public and community options that offer STI care in Houston, with what each organization publishes:

Houston Health Department health centers. Northside Health Center (8504 Schuller Rd., 77093), Sharpstown Health Services (6201 Bonhomme Rd., 3rd Floor, South Tower, 77036) and Sunnyside Health and Multi-Service Center (4410 Reed Rd., 77051) offer STD and HIV services. The Houston Health Department lists a sliding scale for cost. The number is 832-393-4220. The department says walk-ins are accepted as capacity permits, and that appointments have been encouraged since September 1, 2026.
Harris County Public Health Antoine Clinic (5815 Antoine Dr., 77091). The county lists testing for HIV, syphilis, gonorrhea and chlamydia, with services described as free. Phone: 832-927-7350. Its page lists Monday to Thursday 8am to 7pm, Friday closed, and some Saturdays 8am to 2pm, so confirm before you go.
Legacy Community Health, Montrose (1415 California St., 77006). Legacy says services are open to all regardless of ability to pay, and that a full STI panel is offered as appointments are available. Its page does not state a price for the full panel. Phone: (832) 548-5100.

Avenue 360 and The Montrose Center list free rapid testing for HIV, hepatitis C and syphilis. The Montrose Center says it does not offer a full STI panel. For M. genitalium, those two are unlikely to be the right fit, but they are useful for the tests they do offer.

For addresses, services and hours in one place, see our list of Houston testing clinics. For a broader look at cost and what to expect, read STD testing in Houston: where to get tested and what it costs.

You can also use the CDC's locator at gettested.cdc.gov to find testing sites by ZIP code.

A note on mail-in options

Texas DSHS lists a free mail-order self-collection kit through Test for Texas for anyone in Texas aged 13 and older. DSHS describes it as covering HIV, syphilis, gonorrhea and chlamydia. It does not list M. genitalium, so it is not a way to get that specific test. It can still be useful for the infections it does cover.

Local context

The Texas Department of State Health Services (DSHS) 2022 surveillance report counted 31,406 chlamydia cases and 12,935 gonorrhea cases in Harris County. These are the infections that most often share symptoms with M. genitalium. State surveillance does not publish M. genitalium counts in the sources reviewed here, so there is no local figure to quote. That is another reason the practical step is to ask a clinician what they can test.

Questions to bring to your visit

My symptoms came back after treatment. Could a test for M. genitalium be useful?
Does this clinic run that test, or send it to a lab that does?
Does the test check for resistance markers?
How long will results take, and who will contact me?
Should my partner or partners be evaluated?

Asking these questions is routine. Clinicians hear them often, and no one needs to explain their private life to get good care.

Mycoplasma Genitalium: What It Is and Where to Get Tested in Houston