@cornwallis
I purchased doxycycline tablets from Mexico, only one box of 10 tablets. I experienced with several low doses, and can recommend staying below the 40mg to avoid development of bacterial resistances.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4421036/
I experimented with the following dosages:
On the first day, I took half a tablet (50mg) and experienced slight intestinal discomfort.
This prompted me to reduce the dose to 25mg once every 24hours. After about 2 days of this I increased the dosage to 25mg every 12 hours, this was in an attempt to keep reducing the bacterial load at a steady pace. Keep in mind I did this without any advice or instruction from any doctor or medical expert.
I ended up only consuming about 225mg total, and have 7.75 tablets left over.
I would recommend staying upright during the first 20-30minutes of consumption and if you can handle it, on an empty stomach. Make sure to be careful with sunlight exposure as doxycycline can make you very sensitive to sunlight exposure.