Minocycline is an oral antibiotic used to treat acne or bacterial infections including respiratory and urinary tract infections.  The therapy is currently being studied for use in people with relapsing-remitting multiple sclerosis (RRMS) because its anti-inflammatory properties may possibly reduce myelin damage caused by inflammation.

Phase 2 multicentric and parallel group study (NCT01134627) to determine the effect of minocycline in combination with interferon beta-1a in RRMS patients was terminated in 2013. It showed no statistically significant benefit.

But a Phase 3 (NCT00666887) double-blind placebo controlled Canadian study of minocycline in people with clinically isolated syndrome (CIS) was completed in 2015. CIS refers to the first episode of neurologic symptoms that lasts at least 24-hours and is caused by myelin damage. Study results showed that doses of 100 mg of oral minocycline twice daily for six months reduced the relative and absolute risk of MS in people who experienced CIS by 44.6% and 27.4%, respectively.

The results of the Phase 3 study encourages the development of larger minocycline studies.

The most common side effects of minocycline are diarrhea, dizziness or light-headedness, skin and gum discolorations, sun sensitivity, and fungal infections.

Note: Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.


  1. https://www.mssociety.org.uk/ms-research/treatments-in-the-pipeline/minocycline
  2. http://onlinelibrary.wiley.com/doi/10.1111/ene.12953/full
  3. https://multiplesclerosisnewstoday.com/2015/10/13/insights-promising-ms-therapies-late-breaking-news-session-ectrims-2015/