Mycoplasma Genitalium
Free risk assessment
Do I Have Mycoplasma Genitalium?
Mycoplasma genitalium (often shortened to M. gen or Mgen) is a common but under-recognised bacterial STI that frequently causes no symptoms at all. When it does cause them, it's a leading cause of urethritis — and of urethritis that keeps coming back after treatment — and it can lead to cervicitis and pelvic inflammatory disease. Answer a few questions about your symptoms and exposure to see how concerned to be and what to do next. This is a guide, not a diagnosis.
- 100% anonymous
- Under 3 minutes
- No sign-up
- Curable
- Yes
- Resistance-guided two-step regimen: doxycycline first, then azithromycin (if macrolide-sensitive) or moxifloxacin (if resistant or unknown)
- Macrolide resistance
- 50–62%
- In US STI clinic populations; single-dose azithromycin monotherapy now fails in the majority of cases
- Routine screening
- Not recommended
- CDC does not recommend screening asymptomatic people; test those with symptoms of NGU, cervicitis, or treatment failure
- Asymptomatic in women
- Frequent
- Cervicitis and PID can occur without symptoms, making the complication risk real even without a warning sign
How it works
How this assessment works
-
Grounded in public-health guidance
The questions, and how heavily each answer counts, follow the risk factors and symptoms the CDC and WHO describe for M. genitalium.
-
A risk guide, not a diagnosis
Your answers produce a risk level, how concerned to be, and flag anything that needs urgent care. Only a lab test can confirm or rule out an infection.
-
Private by design
It runs in your browser. We never ask for your name, email, or anything that identifies you.
About mycoplasma genitalium
What is mycoplasma genitalium?
Got urethral discharge or burning when you pee that isn't going away — maybe you've already been treated for chlamydia or gonorrhoea and the symptoms keep coming back? Mycoplasma genitalium is worth ruling in or out. It's a bacterial infection that's one of the main causes of urethritis, and it's a common reason symptoms persist after other infections have been treated. In people with a vagina it can instead show up as cervicitis or urethritis, and it's often completely silent, so it slips past the standard panel unnoticed.
The catch with M. gen is that most standard STI panels don't look for it, so it tends to get caught only when a clinician goes looking after other results come back clear. Getting the right test — a NAAT on urine or a swab — is what pins it down, and because the bacteria are frequently resistant to the usual antibiotics, being seen matters so treatment can be guided to what will actually clear it. This check weighs your answers to show how concerned to be and what to do next.
Many infections are silent. A low result here doesn't rule mycoplasma genitalium out: if you've had a new partner or any concern, testing is the only way to be sure.
Screening guidance
Who should get tested for mycoplasma genitalium?
Testing for mycoplasma genitalium is guided by symptoms, a known exposure, or a partner's diagnosis rather than routine screening, you test when you have a reason to.
- 1
You have symptoms of urethritis or cervicitis
Urethral discharge, burning when you pee, abnormal vaginal discharge, or bleeding between periods or after sex are the kinds of symptoms a NAAT for M. genitalium is designed to investigate. Testing is aimed at people with symptoms rather than routine screening.
- 2
Your urethritis keeps coming back after treatment
Persistent or recurrent nongonococcal urethritis — symptoms that return after a course of antibiotics — is a classic reason to test for M. gen specifically, since it's a common culprit and can be resistant to the first-line drug.
- 3
A recent partner tested positive
Sex partners of someone who has tested positive should be tested and treated, even without symptoms, to clear the infection and stop it bouncing back and forth between partners.
- 4
You have signs of pelvic inflammatory disease
In people with a vagina, M. genitalium is linked to PID. Lower-abdominal or pelvic pain — especially with fever or pain during sex — is a reason to be seen and tested promptly rather than waiting.
Timing
When a mycoplasma genitalium test is reliable
Like other bacterial STIs, M. genitalium is generally detectable roughly 1–3 weeks after exposure, so a test taken very soon after sex can miss an early infection. If you were exposed only a few days ago and test negative but still have symptoms, it's worth repeating the test after the window has passed. The test itself is a NAAT run on a urine sample or a genital or rectal swab — remember it usually isn't on the standard panel, so ask for it specifically.
If you're having symptoms, don't wait out the full window before seeing anyone — a clinician can assess you, arrange the right test, and, because resistance is common, guide treatment to what will actually clear it.
Your mycoplasma genitalium testing window
After a possible exposure, a mycoplasma genitalium test becomes reliable around 1–3 weeks later.
Before day 7 a test can miss it · from day 7 it's reliable · re-test after day 21 if you tested early.
Free tool · not a clinic
When can I test? Exposure-window calculator
Testing too soon can miss an infection. Enter the date of possible exposure to see the earliest a test can reliably detect each STI.
| Infection | Earliest reliable test | Conclusive after |
|---|
Guidance only, confirm timing with a clinician. A negative result before the conclusive date may need a repeat test.
Stats & rates
Mycoplasma genitalium in the United States
M. genitalium prevalence estimates range from 1–2% of sexually active adults in the general population to 15–25% of men with non-chlamydial NGU presenting to STI clinics. It disproportionately affects people with recurrent or treatment-refractory urethritis or cervicitis. Not a nationally reportable condition; no official US incidence figures are published.
- 50–62%
- Macrolide resistance rate in US STI clinic populations, the key driver of treatment failure
Medically Reviewed · Updated
Reviewed by Mark Riegel, MD · Sexual Health Physician · Chief Medical Reviewer
Physician focused on sexual health, STI testing, treatment and prevention, and EasySTD's chief medical reviewer. Owns the condition guides and is the clinical backstop for any page without a more specific specialist. Our editorial guidelines →
2 Sources
Data & references
- CDC, Mycoplasma genitalium (STI Treatment Guidelines, 2021)https://www.cdc.gov/std/treatment-guidelines/mycoplasmagenitalium.htm
- NYSDOH/Johns Hopkins, M. genitalium Management (NCBI Bookshelf)https://www.ncbi.nlm.nih.gov/books/NBK583532/
Good to Know
Mycoplasma genitalium FAQs
What people ask most before testing for mycoplasma genitalium.
What are the symptoms of mycoplasma genitalium?
Often there are none — many people carry it without noticing. When symptoms do appear, people with a penis tend to get urethral discharge, burning when passing urine, and urethral irritation (the picture doctors call nongonococcal urethritis, or NGU). People with a vagina may notice abnormal discharge, bleeding between periods or after sex, painful urination, or pelvic discomfort. Because it's so often silent, it's frequently found only when symptoms persist after other tests come back negative.
How is mycoplasma genitalium spread?
Through vaginal and anal sex — genital contact with an infected partner. It can infect the urethra, cervix and rectum. Oral transmission has not been established. As with other STIs, ejaculation isn't needed for it to pass, and someone with no symptoms can still pass it on.
How is mycoplasma genitalium tested for?
By a NAAT (nucleic-acid amplification test) run on a urine sample or a genital or rectal swab. Crucially, it is not included in most standard STI panels, so you often have to ask for it specifically — it's commonly checked only after chlamydia and gonorrhoea come back negative but symptoms persist.
Why is treatment sometimes complicated?
M. genitalium has become resistant to the common macrolide antibiotics in many cases, so a single standard course doesn't always clear it. Because of that, clinicians increasingly prefer resistance-guided treatment — testing which antibiotics the infection will respond to, then treating accordingly — which is why it's important to be seen by a clinician rather than self-treating.
Should I get tested if I have no symptoms?
Routine screening of people without symptoms is not recommended. Testing is aimed at people with symptoms of urethritis or cervicitis, persistent or recurrent NGU, signs of pelvic inflammatory disease, and the sex partners of someone who has tested positive. If a recent partner tests positive, it's worth being tested even if you feel fine.
Have a different question? Browse the full STD & STI FAQ library, every question we answer, in one place.
Keep reading
More from the health library
HIV & AIDS
HIV Awareness and Your Children