anyone experience abnormal menstrual cycle? I stopped getting my...

Based on this website:

http://drugs.medsort.com/drugs/DrugLabel.aspx?MedID=4050

They say that it takes the medication about 18 hours to leave your system. Hope this helps! There is a bunch of other neat info about the drug on this site, too.

I have experienced the same thing. I have stopped taking it and mine still is not here. I think it's best to get in touch with your doc.

Well I have been off it for about 9 days now and no show of my cycle.
Since I am out of the country and can't get in touch with my doctor, I was wondering if anyone knew of good websites realted to Doxy's relation to hormonal affects...please post anything that could be useful. Thank you for the above link although I have yet to find anything realted to my topic.

Reply to #40278. Yes! My periods were very light and eventually stopped except for one day of light bleeding (I took Doxycycline in 4 rounds of 3 months each for 14 months, and have been off of it for about 2 months). My bacterial infection appears to be gone now and I have improved but menstrual periods have stopped except for the one day of light bleeding, hardly noticable. Doctors and pharmacists claim Doxcycline could not have this effect; however, I have had 28 day periods for 5 days each period for a lifetime and this did not change until taking Doxcycline and when I was pregnant earlier in my life. I suppose could be perimenapause. I also noticed an almost imperciptible and gradual decline in my mood (depression) which signficantly improved within several days to a week after taking Doxycycline. The only thing I can find about side-effects relating to this drug are that birth control pills may become less effective and to use another form of birth control during the time of taking the drug. Doesn't that suggest that perhaps harmones might be effected? My pharmacist thought so but could find no conclusive work on this. Don't know. If I start, I'll post a reply that I did. Otherwise, I am certain it effected my menstrual cycle.