Did you know that antibiotics could affect the menstrual cycle? Indeed, most of them can have an effect on menstrual periods, with some reporting delays. Find out more about the connections between antibiotics and the menstrual cycle below.
Your Regular Cycle
During the first 14 days of a 28-day menstrual cycle, your follicle will start to grow and kick-start the initial production of additional estrogen. It will start to make the endometrium lining thicker. When ovulation commences, the estrogen hormone will be joined by the progesterone hormone from the corpus luteum to make the endometrium mature and thicker.
How Antibiotics Affect the Normal Cycle
Antibiotics can interfere with your body’s mechanism, which secretes the human chorionic gonadotrophin hormone (hCG) and cause uterus shedding to delay your period. This will happen mainly because the available estrogen will be reduced to cause a change in your cycle for it to become irregular.
A study done in 1947 shows that Penicillin caused heavier bleeding, changes in pain and PMS symptoms and the start of the cycle itself, but they stated that they weren’t able to find any correlative information regarding that.
There are actually two ways antibiotics could affect the estrogen metabolism. Most antibiotics are metabolized in the liver, and when they are present, the metabolism rate of estrogen as well as progesterone will be affected. This can interfere with the estrogen supply that is in the blood and causes an irregularity of the menstrual cycle.
In order for the follicular phase of menstruation to occur, the estrogen is needed to stimulate the ovaries and thicken the uterine wall. Without this, ovulation doesn’t happen or it happens late, which obviously affects when your period will arrive.
Other Issues with Antibiotics
There are some antibiotics that will cause diarrhea-like symptoms when they interfere with the stomach flora.
Even though it’s supposed to kill the bad bacteria in the body, it also affects and kills the good bacteria as well, which is why some women report yeast infections as well after their use of antibiotics.
The entero-hepatic circulation will be affected and cause a reduction of estrogen levels in the blood. It’s becausegut bacteria that usually re-activates small amount of estrogen in intestine are no longer available [1].
When the estrogen levels change in the blood, your cycle will be affected low estrogen levels fail to stimulate pituitary release of hormones. Your body actually ovulates based on the pituitary gland’s ability to identify that sufficient estrogen is in the blood, and then cause LH surge which causes ovulation on 14th day of cycle. So antibiotic treatment can affect these delicate hormonal balances.
So your body doesn’t have enough estrogen to regulate normal menstrual cycle.
Another important point to note is that antibiotics change your body’s metabolic performance and the ability to sustain a steady hormone level.
Use the Second Form of Protection if you are Not Trying to Get Pregnant
Antibiotics can also affect the estrogen as well as progestin levels in oral contraceptive pills. Estrogen is actually an active ingredient in these pills and the antibiotics will affect how it’s metabolized in the body.
Rifampicin and Rifabutin are liver enzyme-inducing drugs and can clear the estrogens from blood at faster rate thereby reducing the contraceptive benefit anticipated from contraceptive pills.
You should get medical advice if you are taking antibiotics in the first seven days of a new pill packet and you engage in sexual intercourse in the last five to seven days. The antibiotics could disrupt the normal protection that the pills provide and cause you to get pregnant.
So if you are taking antibiotics, ensure that you are also protecting yourself as well if you are not looking to have another child right now.
Reasons other than antibiotics that affect your period
While antibiotics get a bad rap regarding the effect on the body and the menstrual cycle, there can be other potential issues and situations that can go on with the body during the time frame. When sick, antibiotics or not, the body is being stressed to the max.
It is trying to accommodate for being sick and the stress of still having to maintain a home, a job, children, a spouse (because you know, moms don’t take sick days). So take into consideration that it can be affected by the meds or by stress, weight loss or gain, usage of birth control, and PCOS or thyroid conditions.
How to Prevent Antibiotic Related Period Issues
One way to help balance your hormones while you are on antibiotics could be to switch up your diet while you are taking antibiotics (and after as well if you are looking to maintain a healthy balance).
In order to balance the estrogen levels, you can add some fish oil, vitamin D, and vitamin B to your diet as well as probiotics, which can help balance that gut bacteria in a beneficial way.
Plus you’ll want to get enough sleep (which helps so many bodily systems) and be stress free (see above).
In general, antibiotics can affect so many bodily systems. Know that they shouldn’t be something that you take on a regular basis because it can cause antibiotic resistance in the body.
Take them only if necessary and ensure that you take the proper precautions for preventing pregnancy and keeping your other systems in balance.
If your period is still late, however, take a test and be confident with the results. But if you are still concerned with what is going on, be sure to talk to your doctor if you need more information on the effects of antibiotics and menstrual cycle.
References
- Estrogen-gut microbiome axis: Physiological and clinical implications. https://www.ncbi.nlm.nih.gov/pubmed/28778332
Hi, i got a cut on my hand and had to get stitches and it turned out to be infected. On the same day as my period i started antibiotics for ten days (4 days longer than my period). It is the next month now, i have finished my antibiotics but i am now 2 days late for my period. Would that be because of the antibiotics. I am stressing out because i might be pregnant. I took a pregnancy test but it turned out to be negative. Help!
Hi Emily, yes antibiotics can effect your periods and cause delay.
I was prescribed 2 different antibiotics for a sinus infection about 3 weeks ago. Since then I had unprotected sex and I was supposed to start my period 11 days ago. Should I be worried or is it just the antibiotics? Please help, I’m getting worried! Thanks!!
Hi Raquel, Taking antibiotics can affect your menstrual cycle. The most common result is that it delays your period. This has to do with the way that the antibiotic affects the breakdown and uptake of estrogen in your body. Obviously if you have concerns you should seek qualified medical help.
Hi I’m 5 months postpartum. Diagnosed with BV. I took metronidazole for 7 days, my period supposed to due last may. 28. But it didn’t come until now.
My period delay for few days now and just finished my medication last week Thursday I’m a bit worried is nexium/nexole can also delaying my period?
Hello Tessa, yes medications do sometims effect your menstrual cycle and may delay it.
Hi, I had boil under my armpit and I was prescribed with Ampiclux. I was supposed to see my period on the 22nd. I just finished using the Ampiclux yesterday 29th but until now I still haven’t seen my period and I haven’t had sex going to 2months now. Sometimes I feel my period is coming, but when I go to check I see nothing. Please help me, I am worried.
I would check with your doctor. I am not familiar with this medication enough to know if it can disrupt your period. Stress can also make a period late as well. If you were pregnant, you would be showing symptoms by down or at least feeling different.
Hi! My doctor prescribed me antibiotics for 7 days 3x a week..But unfortunately on my 4th day taking of antibiotics i just had my period…Can i still take antibiotics while on my period or should i stop it?Your reply would be a big help..Thanks!
Hello Iyka, you should consult your doctor about this as the doctor best knows about what medication you are taking and what effects it could have on your cycle.
Hi everyone,
I’m a little worried. This month I got really ill and went through 3 courses of antibiotics starting with amoxyl, then levaquin and then clavulin. During the time I was ill, i stopped the use of my antidepressant, wellbutrin. I had sex with my partner maybe 8 times since my last period but always ALWAYS with a condom. We also check for leaks afterwards and everything looked fine. Yet my period is 9 days late and I still haven’t gotten it. I’ve been getting cramps but it may just be intestinal. I also had alot of watery discharge while on my last course of antibiotic around the time I would have normally gotten my period. Around that time I was also having a lot of yogourt and kefir to try and rebalance my intestinal flora. I read eating those foods as well as being on antibiotics could very well cause vaginal discharge and of course there’s often a risk of yeast infections while on antibiotics. I also felt a burning sensation for maybe 1-2 days but it seems to have past. Anybody else been through something similar? Is it time to get a pregnancy test?
Hello Sianab, Antibiotics do effect your mestrual cycle and you could be late because of it.
Can someone please help? On April 10 I had my last period. It wasn’t as much as usual, but it was there. 4 days later I went to the doctor and he told me that I had a bladder infection and put me on antibiotics for 5 days. I still haven’t got my period. Need I be worried?
I used antibiotics recently, expecting my menses 6-8th of May. I actually noticed a little discharge on the 5th. After then it stopped. Then a kind of much discharge on the 6th. But since then, there hasn’t been any discharge. Could it be as a result of the antibiotics?
Hi, the first day of my last period was March 19th, and I had a UTI so i was given Ciprofloxacin HCl to treat it. I started the medication April 13th on the medication, but I was suppose to have my period April 14th, but it still has not came. Could it be from the medication? I’m suppose to take it 2 tabs x 3 days. I’m very worried..
It sounds like our cycles are basically the same and we are in the same situation. My last period was March 22. I was diagnosed about a week ago with a kidney infection and was given Ciprofloxacin 2 times a day. I am now 3 days past due with a negative pregnancy test. I am wondering if the medication is causing my period to be late or if I am actually pregnant.
hi! I was prescribe antibiotic shalcip TZ, i had a combination of ciprofloxicin and tinidazole, i took it for 7-8days, i started taking the on 6th April.. my last period was on 14th of march and my next period was suppposed to be on 11 April but Upil now it is out and there is no sign of it coming soon.. Though i had unprotected sex on the 4th April… Could i b pregnant or could it the effect of the antibiotics?
Hello, antibiotics and pregnancy both can be the reason here. If you have not got your period by today, then please take a pregnancy test.
Hi, I had been admitted for pneumonia last Feb, took 21 days total of antibiotic and Steroid for my lungs, after a month recovery, I have my period or bleeding 9 days early and its not stopping until now its been 14 days now, its started to very light to medium, and there was big clamp of blood that came out that make me scared, doc put me on ibuprofen for 7 days so far its slowing down, but still very worried if it ever will stop, is this cause by meds that I took or should I be worried for other causes, I am regular when it comes to period, I am 37 years old, thanks for reply in advance.
Hi Dhen, antibiotics often affect period, but in your case the effect is a lot. Sometimes other medicines (including birth control pills) can react with antibiotics and that may be the reason too. The best thing is that you went to a doctor. A professional will be able to treat the exact problem. All the best!
Hi, I was prescribed antibiotics Clindamycin 4 tabs x 7 days due to tooth infection. I started taking them from March 19th, had period also on March 19th as it was due and had tooth extraction on March 22nd. My next period should have been somewhere around April 12th, but I had them on April 05th (a bit too early!). Also, I had excess clots on 3rd day not like I normally have about size of a loonie. Please help me…can I relate this to the antibiotics…Im so worried….
Hi Chinnama, yes many antibiotics including Clindamycin can affect your period. About blod clots, usually Clindamycin should enhance the anti-clotting ability. I woul suggest that you consult a professional for that. You can also discuss this with the doctor who prescribed Clindamycin.
Hello, my periods should supposed to be started on Friday, April 1st. Then I started penicillin antibiotic for my throat infection on Saturday. It did not come yet and my periods were very regular. Please answer me whether penicillin has an affect in menstrual cycle.
Hi Ann, usually penicillin alone does not affect periods. If you are taking any kind of birth control pills, then penicillin can cause a delay. Are you taking any other medicines too? Or is there a change of routine (exercise/diet)?
Hi, I had my tooth extracted on February 25th and the dentist prescribed an antibiotic named Clindamycin 2x a day for 7days. My period was due on March 4, up until now, I haven’t had my period. I’m 17 days late. Could it be the antibiotic that caused this? Thank you for the reply. I really need help, please.
Yes, antibiotics can affect your menstrual cycle; it can cause delays. You need to take a pregnancy test to ensure that you’re not pregnant though. For more information on how antibiotics can affect your cycle, read more here http://womanjunction.com/antibiotics-and-menstrual-cycle/ .
I took a pregnancy test yesterday and today and the result was negative although I have my
usual sign of having a period, for instance, my nipples are sensitive.
Sensitive nipples can be attributed to PMS as well. Make sure that you’re not testing too early.
Is 18 days late too early? Should I test again tomorrow? Thank you so much.
Ok, reading all these comments here and I’m like the rest of you. Was supposed to start by the 9th of this month. So almost Ten days late and have been on different antibiotics since 2/23. I’m NEVER late. I took a test two days after missed period and was negative. Should I retest or wait it out?
I have the same problem as yours. Did your menses show up?
Hi Stephanie. Antibiotics can have an affect on periods causing them to be delayed. If you think you’re pregnant you should test again. If you are not satisfied with the result you should talk to your doctor.