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
Hey There. My last period was on the 5th of Jan. I have regular periods. Today is the 9th Feb and I am not seeing my period. I am experiencing some white discharge . I had unprotected sex in Jan and early Feb. I was on some antibiotics for vaginal infections in Jan after my period. I am currently experience sore breast. Is there any way I am pregnant? Very worried. I am 19.
Hello Unknown, there’s always a chance that one might be pregnant having had unprotected sex, however the taking of antibiotics can cause weird symptoms and can delay your menstrual period.
Okay thanks. how can I get pregnant very fast. I am 19 will be 20 april
Hello there Unknown, I hope the following link helps you: http://womanjunction.com/category/ovulation-signs/
Hi, thanks a lot for the article.
My period is almost every 32-34 days. My last period was started on 29.12.16. I had flu with fieber (40 degrees for 2 days) and sorethroat. That sickness was started on 14.01.17 so directly in the middle of my menstrual cycle. I took 1000mg×2 antibiotics and flu medicines for 7 days. So today is 7.02.17, my period hasnt started yet. Should I buy a predictor test? I am afraid to go to doctor 🙁 any suggestions?
Btw: my body has all the period causes like sensitive breast, acnes on the face etc.
Thanks
Hello Melanie, since you are afraid to see the doctor, buy a pregnancy test and use it. All the best!
I was on a Z-Pak for 5 days the first week of January. My period is now 4 days late. Typically my cycle is 28-30 days; today is day 34. I don’t want to waste money on a preg test if it’s likely the antibiotic is messing with my menstrual cycle. Any ideas?
Hi there Megan! Antibiotics usually don’t affect your period but the illness itself can. You should ask your doctor about it. Best Regards
hi i have been taking tarivid antibiotics for 6 days and my period is now late for 12 days and tested last 5 days for pregnancy and found negative. does the antibiotic have any effect of the delayed menstruation?
Hi Aisha, yes, taking birth control can mess up one’s cycle, if this does not normalize see your general practitioner.
Hi, I started taking Amoxicillin 3 pills a day for 10 days and started my cycle 4 days early after it was down for the normal 5 days. I’ve gotten another full cycle and it’s only been 10 days. On top of that I’ve developed a UTI and was prescribed Macrobid. Could taking the antibiotics cause my cycle to be affected? I’ve had normal periods all my life and this is the first time I’ve had irregularity.
Hi there Michelle! There is no interaction between menstrual period and Amoxicillin and Macrobid. There are many other reasons for a delayed period, or a missed period, and most of the antibiotics don’t cause any menstrual cycle irregularities. You should consult your doctor for this. Best Regards
I took Cipro twice a day from Dec 28th – Jan 3rd. (7 days) for a UTI. My period was due Jan 17th. It is now the 25th… I am 9 days late. My breasts have been sore since the expected period day, but no period. I could be pregnant, but not too likely… we did have unprotected sex, but he never finished inside me, and the pregnancy test I took yesterday was negative. I will be taking another test in a week. Just curious if this was common with Cipro?
Hi Casey, yes Cipro might alter your cycle and cause a slight shift in your cycle. If things have not normalized take another pregnancy test to confirm.
I was on an antibiotic for 7 days, approximately 2-3 weeks ago. I haven’t taken medications in over 4 years, nor have i done an antibiotic in almost 20 years. I was suppose to start my period 4 days ago. We are trying to conceive so now I am concerned that if miss my cycle, that means I miss ovulation too. How late will I be or could I possibly miss my period altogether? And is there something I can do to help reverse this impact of the antibiotics, other then a probiotic.
Hey there Kim! Most of the antibiotics don’t interact with the menstrual cycle but some do. I don’t know which antibiotics you are taking. You should ask your doctor about this one. Best Regards
hello! 2 weeks before my period i’ve been on 6 different antibiotics. still on them, with 6 days being late for my period. experiencing cramps and been bloated and headaches. i’ve had light pink mucus but nothing after that. can you still have period symptoms with being on antibiotics but no period?
Hi there Samantha! You should consult your doctor for this. Regards
i am two days late from my menses,I took infection drugs for 5 days
Hi there Tonia! Wait for at least one week for your period after the expected or calculated date.
Hi i had protected sex on dec.26 and i started taking augmentine 800and amoxicillin 125 together for a really bad sinus infection on the 29 my period was suppose to come on the 31 and now it is 3 days late should i be worried or take a test? my doctor told me to eat lots of yogurt and take a probiotic
Hi there Mariah! You should stick with your doctor’s advice and you will be fine. Regards
Hi,had my period last week. now I have been using antibiotics for 2 days and have started again another period. should I stop the antibiotics?
Hi Tsitsi, I don’t think you should stop you antibiotics treatment. Your cycle will return to normal as soon as you finish your treatment.
Hi I have been taking my antibiotics for almost 2weeks now. Within the third day of taking then I started my cycle (after being off for only 10days) I have been bleeding for 11 days straight. Is this normal???? Also when I first started taking them I didn’t realize I was suppose to take 4 a day (2 of each kind) instead I was taking one of each for about 2/3 days. Did this affect my cycle?? Please help
Hi there! Antibiotics can change your menstrual cycle. You should always ask your doctor about the interactions of the drugs with your body, food, menstrual cycle, he/she prescribes you. Regards
I finished my antibiotics one week ago and I supposed to see my period on 4th last two days but no sign sign since then Pls what can caused it?
Hi there Jecinta! Antibiotics can affect your periods. You will get your periods in a week. Regards
Hi!
Been taking geniclox (ampiccillin & cioxacillin) capsule four days before my menses started today, should I discontinue taking it or continue, just want to be sure so it doesn’t have a negative effect on me.
Thanks
Hi there! You should consult a doctor or a pharmacist for this. Regards
Hi, am Hannah , i was on cipro for 14 day to treat UTI , I saw my period for half day ,and since then i have not seen it. Is it the antibiotic that caues it.
Hi there Hannah! Most of the antibiotics don’t interfere with your periods. You should ask your doctor about the antibiotics he/she is giving you. Regards
Hi I had antibiotics for seven days towards the end of October last month, my period came on the 14th of November and it was not as heavy as it used to be and lasted for barely three days. Could it be the antibiotics or I’m pregnant
Hi there Tee! Please refer to this article. for information. Regards