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
I have a jaundice and typhoid and its my periods time, but I am spotting sometimes not having complete mensuration. Is it because of medicines or something else had happened.
Hello Suraya, if these are two new sicknesses you are experiencing and prior to this your cycle has never been interrupted then the medication given might be causing some delay in your period returning.
I had Bv and a yeast infection. I was taking metronidazole and using terazol for a week. I had sex the day after I took my last pill and the day after that my period started! My period is usually light the first day or two but It’s day 5 and it’s still very light!! So light that I only see brown or red when I wipe. It’s not even flowing enough to stain a pad or panty liner. I also took an early detention pregnancy test and it was negative.
Hello Kyle, if you have symptoms thereafter you can redo the pregnancy test, however one of the times a pregnancy test is most accurate is 7 days after a missed period.
I had unprotected sex on the 27th of last month, he didn’t release in me. My ovulation day was on 30th of the same month. I am treating staph & candida, taking Levi since d 15th of this month & my period has delayed by 5 days. What can be the problem?
Hello Valerine, the taking of antibiotics might be the cause for your menstrual delay.
Hi… I have been on antibiotic for a while and then I started noticing something like a bloody discharge, but it’s not rushing, it’s just there and when I wash I wash out blood from my vaginal but the confusing part is its not even coming down to stain the pad.. it’s just there in my vaginal… I dunno if it’s caused by the antibiotic, and I dunno how long it’s going to continue like this, because it’s three days now…I don’t know if I am to stop the antibiotic for a while and allow the blood able to rush or I just continue and wait for it to stop.
Hello Nala, you did not mention what you were using the antibiotic to treat, however, I advise that you maintain taking the course of the antibiotics.
Hi. I have a 4 day cycle. But last month I got it right on time but for 5 days which was November 1st. And to my surprise 2 weeks later November 23 I got another period and now I’m late 4 days late. I’m taking an antibiotic so should I worry or not?
Hello Layla, the antibiotic is more than likely the cause for this.
Hello Alison, the first day of my last period was the 13th October, I went to the doctors for an ear infection on the 24th October, I was on antibiotics (The first week one pack of antibiotics cannot remember the name and the last 2 weeks were flucloxacillin) for almost 3 weeks, I have not had a period since October, done plenty of tests and all negative, I’m not sure if it’s in my head of feeling pregnant.
Hello Abigail, the antibiotics is more than likely the reason for this. Your period should come back naturally soon.
Im 13 days late and took PT thrice its all negative. I just finished taking antibiotic for my gums. Is it possible? Or because of the antibiotic i took?
Hello Abby, the antibiotics you took is more than likely the reason for your delay.
Hello I am on birth control and my bf came inside me last Sunday 12/10/17. The next day I got UTI symptoms and turns out I had a UTI and took 1 of the antibiotic pills but i did not continue taking them because i feared it would mess with my birth control and make me ovulate or something and get pregnant since sperm can live up to 6 days. I continued taking my birth control pills normally. Anyways i’m taking the placebo pills and im almost done with them and havent gotten my period. Could it be delayed because of the antibiotics?
Hello Lynn, yes your period might be delayed as a result of taking the antibiotics.
Hi I’m Jean ,my Derma prescribed me to take Doxycycline hyclate 100mg twice a day. I started that antibiotics in m 27th days but now im 9days delayed but not pregnant base on Pregnancy Test. Do I have to stop taking antibiotics to get back my normal cycling period?😩
Hello Jean, please maintain the course of your antibiotics as prescribed by your doctor. Your period will return naturally.
I was having dengue fever from 18 oct 2017 to 25 Oct 2017 and periods came on 22 october 2017. after that I haven’t have any periods till today. I had taken so many tablets during fever so is this the reason of delay in periods. please suggest me I’m in tension. I am unmarried.
Hello Sheena, did you take antibiotics? If so, this might be the cause for your delayed period.
I had my menses on 7th November and had unprotected sex on 12th…..but my b.f used withdrawal……after a week I suffered pneumonia and was under medications……am worried because I have not received my periods till now……could I be pregnant or what is the problem?
Hi there Melisa, apart of the medications you took could have also been anti-biotics which might be responsible for your delayed period.
Hi..I was prescribed tarivid ofloxacin for a UTI and I want to know if its okay to try to conceive at this time as my ovulation falls within the period of medication..
Hello Chilax, you can still try around this period once the UTI is not very bad for you.
I had sex on the 29 of nov, according to my app I was not really but ovulating, because the 28th was like the day my ovulation was big, anyways I had unprotected sex but he didn’t finish in me but since the 29th of the night I had to take antibiotics for like 3-5 days cause I had work on my gums, the thing is that I haven’t got my period. I always get it between 6th-9th
Hello Mel, the antibiotics might be the reason for your delay.
Hello, I had unprotected sex Nov 7th, then took plan B Nov 9th. A week later I was taking antibiotics for a UTI infection. My period was late and I took two pregnancy tests and they were both negative. I’m not sure what’s wrong.
Hello Rylie, the UTI may have delayed your period.
Hi Alison,I had unprotected sex on the 25th of DEC and I was ovulating that period,like a week after I had unprotected sex but took contraceptive,I started using antibiotics,and have been bleeding seems to be my period and it just extra early.
Hello Princess, yes with the taking of anti-biotics your period might be delayed or come earlier than expected.
I had pneumonia on oct 28. Had ten days worth of levaquin and a z pack. I got my period nov 3. Had unprotected sex November 11 and he pulled out. It is now cycle day 33 and no period. Tests are negative. Could it still be possible?
Hello Cynthia, the antibiotics you took for the pneumonia seems to be the reason why your period is delayed.