40 mg anti-inflammatory-dose doxycycline for rosacea (phase III, 2007)

This paper reports two separate phase 3 trials run in parallel. In both, people taking 40 mg controlled-release doxycycline once daily lost about twice as many inflammatory lesions over 16 weeks as those on placebo. The dose is deliberately below the level that kills bacteria — it works by damping inflammation instead, which is why it does not carry the usual antibiotic-resistance concern. Side effects were mild and uncommon. Two independent trials agreeing is what makes this strong.