Chlamydia is the most commonly diagnosed sexually transmitted infection (STI) in the UK, with over 200,000 diagnoses recorded annually. Because it frequently causes no symptoms, many people are unaware they are infected — yet untreated chlamydia can cause serious long-term complications including pelvic inflammatory disease, infertility, and ectopic pregnancy in women, and epididymo-orchitis in men. Azithromycin provides a fast, highly effective, single-dose treatment that is NICE-recommended as a first-line option for uncomplicated chlamydia.

What Is Azithromycin and How Does It Work?

Azithromycin is a macrolide antibiotic — a class of antibiotics that kill or inhibit bacteria by binding to the bacterial ribosome and blocking protein synthesis. Unlike many antibiotics that are confined to the bloodstream, azithromycin concentrates inside cells and tissues, making it uniquely effective against intracellular pathogens like Chlamydia trachomatis, which lives and replicates inside human cells rather than in extracellular fluid.

This intracellular activity, combined with azithromycin’s extended tissue half-life, is why a single 1g oral dose is sufficient to clear most cases of uncomplicated urogenital chlamydia.

Azithromycin vs Doxycycline for Chlamydia

Both azithromycin and doxycycline are NICE-recommended first-line treatments for chlamydia. The choice depends on individual factors:

• Azithromycin 1g (single dose): Preferred where adherence to a multi-day course is a concern; single dose is often more convenient and ensures the full treatment is taken
• Doxycycline 100mg twice daily for 7 days: May be preferred in pregnancy (first trimester: erythromycin preferred), or for rectal/pharyngeal chlamydia infections where azithromycin may have lower efficacy
• Both achieve cure rates of over 95% for uncomplicated genital chlamydia when taken correctly

What to Do After Taking Azithromycin for Chlamydia

1. 1
   Avoid sexual contact for 7 days — including oral sex — after both you and any partners have completed treatment.
2. 2
   Notify recent sexual partners — anyone you have had sex with in the previous 6 months should be informed and encouraged to test.
3. 3
   Retest after 3 months — BASHH guidelines recommend retesting 3 months after treatment, as reinfection is common.
4. 4
   Test of cure — required if you were pregnant, had rectal or pharyngeal infection, or if symptoms persist 3–4 weeks after treatment.

The Access Doctor Process

Accessing azithromycin through Access Doctor is straightforward, private, and clinical:

• Complete a confidential online health assessment — no GP appointment needed
• Your consultation is reviewed by a GPhC-registered pharmacist independent prescriber
• If azithromycin is clinically appropriate, a prescription is issued following NICE and BASHH guidance
• Treatment is dispensed by our UK-registered pharmacy team and sent in discreet, plain packaging
• Next-day tracked delivery available across the UK

Side Effects and Safety

Azithromycin is generally well-tolerated, particularly when taken as a single dose for chlamydia. Common side effects include mild nausea, abdominal discomfort, and diarrhoea. These are usually brief and resolve on their own.

Important: Antibiotic Resistance

Completing the full prescribed course — even when you feel better quickly — is essential to prevent antibiotic resistance. For the single 1g dose used in chlamydia treatment, this is straightforward. If you are prescribed a longer course for another indication, stopping early can allow surviving bacteria to develop resistance, leading to treatment failure and potentially contributing to wider public health resistance problems.