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 was on antibiotics for almost 3 weeks and it caused a 10 day delay in my cycle. Once you start your period, are the effects from the antibiotics gone? Do the antibiotics only affect the cycle you are in when you take them?
Hi Katie,How long antibiotics stay in your system after you finish taking them totally depends upon the antibiotic the person is taking, doses, and the person`s metabolism as well.Generally antibiotics should stay for a week in the system after you finish taking them.
I had a protected sex August this year after which I saw my period August 26-29. After then till now I haven’t seen my period. Though I had a cut on my forehead after my period which was stitched and I collected series of injections including antibiotics and so on. Can this delay my period up to a month or does it mean I am pregnant?
Hello. Antibiotics are known to delay periods so this could be a factor. Your period may also be late because of stress, fatigue or medical reasons. Since you’ve missed your September period, you can now take a pregnancy test to confirm if you’re pregnant.
I took a course of antibiotics since august n haven’t had a period since..I guess its normal for your period to delay but not for so long…I’m not pregnant n hoping it comes soon
Please refer to this link for the answers that you seek http://womanjunction.com/antibiotics-and-menstrual-cycle/
I had to take two intense rounds of azithromycin for a positive chlamydia test after throwing up the first round. Could that cause the delay in my period because it was so much?
Hello Christine, Antibiotics can delay your period, if you have other questions talk to your doctor.
I have taken antibiotics for a bad tooth 500 mg had the intercourse and now my menstrual period won’t stop what’s going on
Hi Yvette Mckines, i am not sure what could cause that to happen but You should visit your doctor to make sure everything is ok and you dont become anemic because of loosing too much blood.
Hi, i took antibiotics for a week. even though it’s been a week later, can the antibiotics cause early spotting/period because i had my period while i was taking the antibiotics and a little over a week later it’s like i have my period again
im not on birth control
Hello Hannah, antibiotics causes changes in the menstrual cycle so yes it can cause you to see your period a earlier.
My last period was 4th sep, on 21st the same month I was treated for urinalysis and was given antibiotics, on 24th night I started vomiting til the next day I stopped taking them and there was blood on my pants, would I be menstruating cause my back aches and there is stain on my pad
Hi Irene, If you are not sure you are menstruating you should visit your doctor and tell him your concerns to make sure there’s no other problem.
Greetings
I was on a 5 day Amoxicillin course beginning of Sept and then recently had to take Azithromycin two days ago. My period delayed by a day and only came for 2 days as opposed to the 5 I usually take.
I’m really worried,
Please help
hi, pls I’ve been on antibiotic for some days now, and my menses came and lasted for only two day. last month it came on the 24th of August and this month it came on 19th September and lasted for only two days instead of four days. can something be wrong?
This helped me so much my period was 4 days late as of yesterday and I kept wondering why, then started to think if the antibiotics I’ve recently started taking was affecting my period, I’ve never been so happy to say my period finally started! Lol
glad to hear that, Stephanie 🙂
I suffered from urinary infection which even inflected my blood as well and I was on periods at that time. I was hospitalized then doctor gave me antibiotic I m fine now but my menstrual cycle is not. I usually have periods for 3-4 days but after this infection I only had for 2 days. Is it something to worry about
Hi Sheetal, Have you talked to your doctor about this? i think you should talk to him about it to make sure there’s no other issue Maybe the antibiotics affected your cycle.
Thank you. Can antibiotics cause extreme cramping? I usually have no cramping at all during my periods. This time it’s torture.
Yes, stomach cramping is a side effect of some antibiotics. Ensure that you’re taking the correct dosage; taking more than the prescribed amount will give you an upset stomach. Also, some antibiotics stipulate if they must be taken with food or on an empty stomach. Ensure that you take them as prescribed by your doctor. Antibiotics affect both the good and bad bacteria in your body; if the good bacteria are attacked it can cause stomach pain. You can eat more yogurt to increase your levels of good bacteria.
I’ve been freaking out for the past week. I’m somewhat at ease now but would like for Aunt Flo to arrive already, that way i know for sure!
This is so helpful! Other websites have said similar things, so my anxiety is starting to subside. I just wish my doctor would’ve warned me of this side effect.
This is very helpful information! I can now put my husband’s mind at ease since I am 4 days late after having been on 2 weeks of antibiotics. Thank you.
can it make me start my first period?