Azithromycin is an antibiotic that can treat the sexually transmitted infection (STIs) chlamydia and some of its complications, such as urethritis and cervicitis. It may also help treat gonorrhea.
STIs are infections that typically pass from one person to another through sexual contact. Anyone, regardless of their sexual orientation or hygiene standards, can contract these infections. Many types of bacteria can cause STIs. To treat these infections, a doctor will typically prescribe antibiotics.
Azithromycin is an antibiotic a doctor may recommend for some STIs. For example, it is a common treatment option for chlamydia and for potential complications from chlamydia, such as nongonococcal urethritis, cervicitis, or lymphogranuloma venereum.
In this article, we will discuss azithromycin, including whether it treats STIs and how to use it.
A note about sex and gender
Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

According to the Centers for Disease Control and Prevention (CDC), azithromycin is the
The results of a 2015 study comparing different antibiotics for treating chlamydia suggest that azithromycin can treat
Other studies also suggest that doxycycline may be more effective for treating chlamydia in both males and females.
Still, the British Association for Sexual Health and HIV states that azithromycin should remain an option for individuals who are allergic or intolerant to tetracyclines, such as doxycycline, and for people who are pregnant.
Additionally, the
- chancroid
- donovanosis
- Mycoplasma genitalium infections
Azithromycin is available in both tablet and powder formulations. The dosage will vary depending on the infection a person is treating. A doctor will advise on the dosage and duration of medication.
For treatment of chlamydia, a doctor will likely
For the treatment of nongonococcal urethritis, a doctor will
Like any other medication, azithromycin can cause side effects. It is advisable to consult a doctor if any of the following adverse reactions are severe or do not go away:
- diarrhea
- nausea
- vomiting
- stomach pain
- headache
Occasionally, a person may experience more serious side effects, which can include:
- fast, pounding, or irregular heartbeat
- dizziness
- fainting
- rash with or without a fever
- blisters or peeling
- fever and pus-filled, blister-like sores, redness, and swelling of the skin
- hives
- itching
- wheezing or difficulty breathing or swallowing
- swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
- hoarseness
If a person is sexually active, it is
STI testing recommendations
- Adults and adolescents aged 13–64: It is advisable for a person to test at least once for HIV.
- Sexually active females: It is advisable that females younger than age 25 test for gonorrhea and chlamydia every year. Females who are over age 25 and have risk factors — such as new or multiple sexual partners or a sexual partner who already has an STI — should test for gonorrhea and chlamydia every year.
- A person who is pregnant: A pregnant individual may want to consider testing for syphilis, HIV, hepatitis B, hepatitis C, chlamydia, and gonorrhea starting in early pregnancy.
- Sexually active males who have sex with males: It is advisable for a person to:
- test at least once a year for syphilis, chlamydia, and gonorrhea
- test at least once a year for HIV
- test at least once a year for hepatitis C if living with HIV
- consider testing more frequently (e.g., every 3–6 months) if they have multiple or anonymous partners
- Sexually active males who have sex with females: There is not enough evidence for screening among males who have sex with females and are at low risk. However, a person may wish to test once they become sexually active.
- Transgender and gender diverse persons: It is
advisable that a person follow screening recommendations based on their anatomy. A person may want to consider annual testing, depending on their risk factors. - An individual who has had oral or anal sex: A person may want consult a healthcare professional about throat and rectal testing options.
Below we answer some frequently asked questions about the use of azithromycin and STIs.
How quickly does azithromycin work?
Azithromycin can take approximately
To prevent passing the infection to others, it is advisable for a person to avoid sexual contact until the infection completely clears.
What happens if a person does not treat STIs?
If a person has an STI and does not receive treatment, their symptoms may worsen and become more severe.
For example, untreated chlamydia
Untreated STIs can also lead to problems during pregnancy, and it is possible for a pregnant person’s baby to contract the infections during delivery.
How to prevent STIs
There are several ways a person can prevent or decrease the risk of contracting an STI,
- Pre-exposure vaccination: Vaccinations can prevent transmission of some STIs. For example, healthcare professionals routinely recommend the HPV vaccine for males and females aged 11 or 12.
- Condoms: When people use them correctly, both internal and external condoms can reduce the risk of acquiring or transmitting STIs.
- Abstinence and reduction in number of sexual partners: A person can prevent STI transmission either by abstaining from sexual activities or by engaging in sexual contact only with a monogamous partner who does not have any STIs.
Azithromycin is an antibiotic a doctor may prescribe to treat STIs that result from bacteria. It is a common and effective treatment option for chlamydia.
Untreated STIs can lead to further health complications. As such, it is advisable for sexually active individuals to take measures to reduce the likelihood of contracting an STI, such as safer sex practices and regular screenings.