Based on CDC | Can azithromycin cure chlamydia with a single 1 gram dose, and when is it safe to have sex again?

Short answer

Yes, a single 1‑gram oral dose of azithromycin can cure uncomplicated genital chlamydia in many cases, and it has long been used as an effective regimen. ^[1] Randomized clinical trials have shown cure rates comparable to a 7‑day doxycycline course. ^[2] After taking a single‑dose treatment, it is generally advised to avoid sex for 7 days and until all partners have been treated to reduce the risk of transmission or reinfection. ^{[3] [4]}

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What the evidence shows

• Effectiveness of azithromycin 1 g single dose
  Azithromycin (1 g taken once) has been recommended historically as a highly effective treatment for uncomplicated chlamydial urethritis and cervicitis. ^[1] In a controlled clinical trial, a single 1‑gram dose achieved bacteriologic cure rates similar to doxycycline 100 mg twice daily for 7 days. ^[2]

• Pharmacologic rationale
  Azithromycin reaches high intracellular concentrations and has a long tissue half‑life, features that support single‑dose therapy for infections caused by Chlamydia trachomatis (an intracellular bacterium). ^[5]

• Practical advantages
  Single‑dose therapy can improve adherence because the entire treatment is completed at once, often under direct observation. ^[1]

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When it’s safe to have sex again

• Timing after single‑dose therapy
  If you receive a single 1‑gram dose of azithromycin, you should avoid sexual activity for 7 days after taking the medicine. ^[3] Guidance also advises waiting until your sex partners have completed treatment to minimize reinfection risk. ^[4]

• If you use a multi‑day regimen
  For a 7‑day regimen (for example, doxycycline), abstain until you have finished all doses and symptoms have resolved. ^{[3] [4]}

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Reducing reinfection and protecting partners

• Treat partners
  Partners should be tested and treated; otherwise, you could be reinfected even after successful therapy. ^[4]

• Retesting strategy
  Reinfection can be common, so retesting at roughly three months is often recommended in many clinical settings to catch new infections, even if initial treatment worked. ^[4]

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Alternatives and considerations

• Doxycycline
  Doxycycline 100 mg twice daily for 7 days is another highly effective regimen and has been widely used. ^[6] Some programs prefer doxycycline for certain presentations due to evolving resistance patterns and co‑infections, but single‑dose azithromycin remains an option in many cases, particularly when adherence is a concern. ^[1]

• Co‑infections and evaluation
  People diagnosed with chlamydia are commonly tested for other sexually transmitted infections (STIs), including HIV, because co‑infections can occur and may influence treatment plans. ^[4]

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Quick comparison

Aspect	Azithromycin single dose	Doxycycline 7-day course
Typical regimen	1 g orally once	100 mg orally twice daily for 7 days
Evidence of efficacy	Demonstrated cure rates comparable to doxycycline in RCTs for uncomplicated genital chlamydia. [2] [1]	Longstanding standard regimen with high efficacy. [6]
Adherence	Often higher due to single observed dose. [1]	Requires completing all doses over 7 days. [6]
When to resume sex	After 7 days and once partners are treated. [3] [4]	After completing all 7 days and once partners are treated. [3] [4]

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Key takeaways

• A single 1‑gram dose of azithromycin can cure many cases of uncomplicated genital chlamydia, with clinical trials showing similar success to a 7‑day doxycycline regimen. ^{[2] [1]}
• Avoid sex for 7 days after the single dose and until all partners have completed treatment to prevent transmission and reinfection. ^{[3] [4]}
• Ensure partners are treated and consider retesting after several months to catch reinfection. ^[4]
• Your clinician may choose doxycycline or azithromycin based on your specific situation, adherence considerations, and local practice patterns. ^{[6] [1]}