What are the side effects of the Pfizer booster vaccine?

side effects pfizer booster vaccine, menstrual cycle
© Ilja Enger Tsizikov

Here, we explain side effects of the Pfizer booster vaccine – with a look at how they impact menstrual cycles

At the moment, richer countries across the world are majority double-vaccinated. In Israel, a fourth dose of booster is even being administered.

Some countries remain in the single digits of vaccination, while dealing with simultaneous other diseases and humanitarian crises. These countries will probably not be majority vaccinated until atleast 2023.

An in-depth investigation found that 120 factories across Latin America, Asia and Africa are capable of producing mRNA vaccines. But they remain legally banned from knowing the recipe, due to pharmaceutical companies seeking profit on their intellectual property.

The Pfizer booster is having similar side effects to a second dose of the vaccine.

What are the common side effects of the booster?

Some of the most common side effects of the Pfizer vaccine include:

  • Tenderness, swelling and/or redness where the injection has been administered
  • Headache
  • Muscle ache
  • Feeling tired (fatigue)
  • Fever (temperature above 37.8°C)

Around 1 in 10 people will experience these side effects, which prove that the vaccine is working to create antibodies.

What about more uncommon side effects?

The more uncommon side effects that 1 in 100 people may experience include enlarged lymph nodes that can last up to 2 weeks, but this can be expected a few days after receiving the vaccine as a sign of the immune system’s response.

A rare side effect that can occur and affects around 1 in 1,000 people may be temporary one-sided facial drooping. Some may also suffer from an allergic reaction, but the data on this is unknown as no cases have been reported.

These side effects are not life-threatening and should simply settle on their own.

Pfizer booster can temporarily impact menstrual cycle

A huge survey of 23,754 menstrual cycles, looking at Moderna and Pfizer booster shots, found no serious or lasting change.

The research, published in Obstetrics & Gynecology, finds that participants had a cycle length can change by only 1 day. This apparently happens only to those who are vaccinated with two mRNA doses, such as Pfizer or Moderna, within one of their cycles.

If the two doses of mRNA vaccines are “timed correctly”, they can temporarily adjust the timeframe for the hypothalamic-pituitary-ovarian axis – also more commonly known as the delicate balance of hormones which allow the human body to produce lining for the womb and expel it, once a month.

This team also disproved that the vaccine creates fertility issues.

However, the authors pointed out that COVID-19 has devastating effects on the same delicate hormones. They say that infection with the virus “could be catastrophic to hypothalamic-pituitary-ovarian axis function, sometimes permanently.”

Does the Pfizer booster make a huge difference in protection?

Research by The Clalit Research Institute finds that a Pfizer booster jab can make the difference between life and death.

The analysis, published in The Lancet, finds that a third dose can decrease COVID death risk by 81%, decrease hospitalisation rates by 93%, and lower risk of severe COVID by 92%.

These percentages are calculated in comparison to double-vaccinated individuals, whose vaccine protection appears to stop after five months. The effect of a third dose is similar across gender, age and even individuals with comorbidities like diabetes or obesity – meaning that it works across the board.

Can the booster vaccine stand up to Omicron?

So far, it seems like the third dose keeps Omicron from creating severe infection. According to new data by scientists at BioNTech, a third booster gives a person enough protection. 

Since the virus has heavily mutated after it left Wuhan, the original form of the virus is what most vaccine-makers used as a template. So, the concern is if the existing vaccines can recognise and stop the much-changed version we have today, whether Omicron or Delta, or a future iteration.

The team found that a triple-hit of Pfizer was able to hold “23-fold increased neutralising titers.”

In other words, the third dose creates the equivalent of two Pfizer doses against the original form of the virus.


  1. I got a horrible red rash – like excema that broke out all over my face 4 weeks after my booster shot. I am a Senior. My face skin started to get red marks after my very first shot of Pfizer and more red spots came onto my face after the second shot. When I got my booster shot, that’s when “all hell broke loose” on my face. I now have a huge red, blotchy rash all over my face and it is very itchy.

    • I got my booster shot of Pfizer 10 days ago and my face especially my forehead has a huge red rash.
      I had Astra Zeneca for my first 2 shots

    • Hi Jeanne, my father is almost 90, never had any skin problems, but 6 weeks after 4th booster like you a severe rash broke out, we’re now 5 weeks on, antibiotics & steroids seem to be working now . Hope you have recovered .

  2. I have severe pain in the arm where the booster shot was injected. It has been over a month and the pain is getting worse. It feels like muscle spasms and continuous sharp pain radiating from my neck down to my fingers.

  3. I have a pain in my arms,,muscle pain down to my hands,,and I’m not feeling well…after inject booster shot lastnyt……jazz pray that im okay,,,

  4. About 4 hrs after my booster I just felt achey all over but they say that’s your body producing antibodies ,that was yesterday I do feel a lot better today and sits a tiny price to pay vs being hospitalized or worse but you’ll be ok don’t worry about it ,it will only make things worse for you

    • Hi mike. I had pfizer shot a week ago. I too had aches in my joints all this started a few days ago from elbows back knee to ankle it got so bad last night i couldnt stand up straight. Back was killing me so put an ice pack across back for 20 mins. Im good today can walk and most pain gone. Will do another ice pack today and some ibuprofen and hope for the best.

  5. I am having a buzzing noise in my head after having Pfizer booster shot . This is still not going away after 5th weeks. Initially for three weeks I have chest pain also. I went to a doctor and on his suggestion had a CT angiogram. The repot came out normal. AS my buzzing noise in head not going away, I went to an ENT specialist and on her suggestion had a head mri done. Will see her this Friday for report on it. I had my initial 2 dose of Astra Zeneca with no side effects. Before Pfizer booster, life was good. But now life is miserable. Hoping to recover but very depressed.

    • I have this horrible buzzing noise too. Feeling fatigue and light headed. I got my booster shot last Thurs. I hope it is the side effect and not me having underlying illness… Been googling about it too, came out titunis… But I just hope it is only temporary setback.
      I hope Yr test result ent came back OK. Let me know


  6. Pfyser booster week later felt dizzy headaches. Dizziness lastes 1 min but staggered me when walking. Felt nauseous in the mornings and rapid heartbeat. Going into 4th. mo. Severe fatigue daily. Age is 72 female.

  7. Had booster shot Pfizer on Sunday, and adverse effects came on Tuesdays early morning,
    Muscle ache
    Feeling tired (fatigue)
    Do i need to provide mc to my employer

  8. Initially I had two shots of Astrazeneca anf 4 months later a Pfeizer booster in early February 2022. I was sick for about 5 days with headache, aches and pains, sore back and dirareah. I’m OK now but not sure about getting more vaccinations in the future. New variants are appearing and nobody seems to know if the vaccine is effective for seniors. I’m 67 . I live in Tasmania Australia where cases are low. Mostly school children are spreading the virus atm. I wear a mask at work, in pubs, restaurants and shopping. Maybe it’s enough to keep us safe.

    • When i got my pfizer booster shot, i feel weak. My arm is still painful and my legs feels like it’s cold. I can’t explain but it’s not the same when I got vaccine of sinopharm. I also experienced headache and back pain 3-4 hours after the shot.

  9. I had two shots of Pfizer Vaccine, 6 months later a Pfeizer booster in early March 2022. I had headache, aches and pains, sore back and now tooth Ache from the upper to the lower jaw . I’m not sure about getting more vaccinations in the future. New variants are appearing and nobody seems to know if the vaccine is effective for seniors. I’m 57. I live in South Africa, Durban, Kwa Zulu Natal where cases are low. I wear a mask at work and and shopping. Maybe it’s enough to keep us safe.


  10. Before I had the pfizer booster I was fit, healthy and full of life. But after I had the booster I have become permanently tired, no energy and dizzy all the time, unless I am sitting down. I had the booster in November 2021 and I was working outside doing a lot of bending work,,,,,,weeding etc. and I did not associate with the booster. I had a blood test which was OK. I went to the doctor’s in February 2022 and he gave me a very thorough check but could not find anything untoward. He suggested that I went for a MRI scan which also showed everything was OK.
    Up to this point I had not thought that It could be caused by the booster because my wife and I had all our injections on the same day. A friend said it could be the booster because she was feeling dizzy for several days after the jab. I am still none the wiser but will get in touch with the doctor again to see what he advises.

    • Government and Pfizer says this is a side affect . They don’t compensate for it but if you are a surgeon pilot truck or bus driver or even driving a car fatigue is a dangerous side affect . Report to TGA

    • I am 49, had the pfizer booster and i havent felt normal. i used to be a regular to the gym now i go to the gym, ezercise and my whole body hurts, every single muscle of my body hurts. I think the mRNA vaccine did something to my nerves and that is why nothing is getting detected in tests. I hope all this is temporary and will wear off.

  11. I had the Pfizer booster, 2/18/2022 right arm. I still have muscle pain from neck to fingers. I feel that my arm is stupid. Also, my arm and hand swelling went do force or carry something heavy. Thank God ,I found this place, i thought i was alone.

  12. I had my booster in December and in February had sudden onset bilateral tinnutus which has now led to chronic insomnia and depression. Before booster i was perfectly healthy and have no underlying health conditions. Has any else experienced anything similar

  13. Had second Pfizer booster April 7 22 on April 11 work up with room spinning and dizziness acute case of vertigo and sore in back and neck felt weak all day and dizziness forward to April 12 no sign of vertigo back a Little sore but that’s normal

  14. I had 2 x Astra Zenica which i was fine on,
    then in December 2021 had the pfzer booster, I came down feel ill within 45 mins,
    since then Ive really not been feeling great at all, both ankles and feet hurt im constantly taking off my shoes as it feels like my socks have fallen down and gathered in the toe of my shoes, and l have lost a lot of sensation in my toes,
    even without shoes on my feet and toes feel strange almost like pins and needle due to poor circulation.

  15. I had the Pfizer booster on 2021-12-09 in left arm. It was sore for a few days snd that is all. But about six weeks ago I suddenly had a very bad left shoulder so bad I couldn’t even lift it. Went to the doctor who sent me for e rays and blood tests. Two days later it went to my hips snd now I can hardly walk. Can’t sleep nights and tired all the time. Feels like a arthritis but it came upon me so quickly, I am wondering if it is something different. The e rays showed nothing and haven’t got blood tests results back yet. Any one else experiencing anything like this.

    • I have the same only it’s not as acute as before but in the past few months I’ve noticed my hair thinning out and feeling brittle. No one seems to report this

    • Hi Wayne,
      My name is Rob Joyce
      I live in Norfolk UK,
      I am experiencing exactly the same symptoms as your self, was wondering if you have any progress in you condition ,ie what kind of treatment you had,or you still experiencing the same levels of pain and discomfort

    • I had the 2 AstraZeneca last year and everything was good and went and had the 3 rd booster shot of Pfizer in January….it’s been six months since the injection …… but I’m still experiencing extreme coldness where I have to get into bed and put the electric blanket on ….fatigue……tiredness……dizziness……. I’ve ended up in hospital twice due to falling over ……and my last blood pressure test was 80/60 ……… I have had so many blood tests ct scans and constant visits to doctors etc etc …….. has everyone else had these symptoms…….

  16. I had 3 phizer jabs no problem. Had morderna booster, in shoulder, left painful, headaches and feeling sickly, 3 days later woke up with pain on left side (jab side), jaws, arms, back,and leg unable to walk without aid. Spent 24 hours in bed Still recovering slowly. Just hope it is worth it.,

  17. I am 79 yrs old and received my 2nd Phizer booster shot this morning and this afternoon I have a slight ringing in my ear and feel light headed. It’s not bad enough to lay down but I’m staying in and not going outside in case I feel more light headed as not to fall down.

  18. As of a few women that have left a response on here, I have the same problem as they do with
    After my Phfizer First booster injection I have had pain that goes down from my neck to my fingers and has been very painful for the last six months.
    The injection was done under my arm near my neck!! No one knows what it is!!

  19. I had my second booster of Pfizer. I turned a pretty shade of pink for about 30 minutes all over my body.My palms stayed pink until the next day. I had a headache and a little body aches. No breathing problems. I am thankful for the availability of a vaccine and will continue to follow the guidelines.

  20. March 26,2022 recieve my pfzer booster
    May menstruatiom didnt come. And when i found out im pregnant a week before i receive my pfzer booster
    Hopefully doesnt effect to my baby im worried.

  21. If your injection was improperly done into the shoulder bursa, it is very painful and can cause a frozen shoulder. You should tell your doctor. Medical providers are trained to inject below the bursa, in the muscle. Some are not well trained or make mistakes. A frozen shoulder injury will need physical therapy.

  22. I just got the booster for Pfizer shot and my arm after 2 days feels like it’s on fire – like a cigar pressed into it. I also had vomited quite a bit and had chills. I didn’t have that with the first two shots. Still not feeling well have to miss work for yet another day. I’m only 56 and not in bad health for a woman – I don’t understand why the shot has knocked me off my feet!

    • I got my booster shot the Pfizer yesterday i was fine yesterday and this morning but out of no where I started to vomit my back is in severe pain im entire left side from neck to toes are in pain and swollen and I have a fever and chills. Also while i was laying in bed the side i got the shot on went numb and i couldn’t move it for a few second. I feel like shit

  23. I received my 2nd Pfizer booster yesterday and my lower back is very much pain. It is pain to bend over. Stand for a while, no mater what i do my back is killing me. Is this related to the booster?
    What can i do?

    • Hi
      I have 3 phizer shots
      Regretting it up to now

      1. All above mentioned some side effects is still with me

      Now 4 months

      2. Something I have to mention is Sinuses
      It’s bad noise in the eardrums skin on my head hurting when sinuses start

      It’s bad really bad
      I Wil never take this vacation again

  24. I got 2 Pfizer booster shots. After the second I slept for 2 1/2 days solid. Wobaly legs etc couldn’t get out of bed.

  25. Hi after my booster vaccine
    I had an ear infection and
    been having alot of colds
    with a running nose now
    I have a cold with a throat
    infection just one cold after

  26. I did Covishield 1st and 2nd dose. I had a lot of side effects; head ache, high fever, burning sensation in the eyes, nostril, indigestion and pain all over the body for three days. The head ache and occasional dizziness went in for 2 months. My menses were heavy and irregular. As 3 rd dose I was offered pfizer as booster dose by the hospital. I am in complete shock with the reaction. I got a sore upper left arm. A deep pain in my upper left side back with a huge swelling and the pain spread to my left ribs and front. My left breast went numb and i feel dizzy. I was offered diclofenac and paracetamol by hospital to control the inflammation. Its already four days and i am not finding relief. What should i do?

  27. I had the Pfizer booster, the first day was ok. But from the third day I have muscles pain and still have an ongoing pain from neck downwards. My left breast feel swollen up to now. My neck hurts up to now -over one week. my lymph nodes feel very swollen and I have been having headaches throughout but have been taking paracemetol. Lifting weight feels like a load these few days. Hope it eases by the end of this week.

    • Consider yourself fortunate. But do consider this, everyone’s body is different and how they respond to these new vaccines will be different considering there age, general health, medications, exercise, and genetic makeup. During clinical trials, scientist can’t cover every existing condition because the subjects are volunteers which are generally healthy people like yourself. So, please don’t label these responses as bogus! The only way for scientist to improve these vaccines is review these comments in real time and hopefully enough people will come forward. Just because you feel fine, don’t mean that others aren’t getting a reaction. After my first booster, I got some discomfort in my right shoulder to my hands, which has numbness and feels like needles and pins policy my fingers. This is real and so is this virus or whatever it is!

  28. I had the booster 2 days ago and my armpit has swollen, can hardly move my arm, headaches, and generally feel unwell. I only had it to go away in 2 weeks. Now I’m told I could have a lump under my arm for up to a month! Great!

    • Hi Heather I have the long too it hurts so bad it hurts just as bad as the vaccination spot along with all these other symptoms I’ve had it for three days now I hope you feel better

      • Hi I’m from Botswana.
        Name and my wife had the 3 booster shots
        Now she are in pain in the area where she hat the injection.
        Swollen shoulder arm put seems like a sak forming under her arm
        She can’t move her arm at all
        It’s 4 days now


  30. Have been troubled with lower back and joint pains after two Pfizer booster jabs. Hands in particular are so bad I can’t make a fist and it is very painful to take lids of bottles and jars. Been like this since first booster in February and not getting any better. Painkillers not helping, paracetamol and tramadol.

  31. Has a yo e reported that their hair is coming out after the second Pfizer shot? I have been losing my hair now for almost 2 months and It’s very upsetting. I am a cancer patient in remission and did lose my hair in 2019 when I was on chemo. If anyone else has experienced this side effect please respond. I am hoping I am not alone.

    • Hi Lori. I am a cancer survivor and cancer-free since 2018. I’ve completed my 2nd dose of Pfizer booster on 30 Nov 2022 last year. So all together i had 2 Pfizer vaccines, and 2 Pfizer booster. Ever since i’ve completed my 2nd dose booster, i noticed i have series of sickness which started of with severe viral fever, subsequently had Influenza B and back to viral fever. Along side, i had severe allergies rhinitis which became worse after booster, skin allergy with rashes, dryness and itchiness, less menstrual circle, headache hair thinning & hair fall (less hair volume now), as well as fatigue and joint pain. I did not had all those previously. My concern now, what could have happen after this and what should i do? I noticed like my body is more vulnerable and weak now, compare to before vaccines and booster were taken. Somehow i’m sure Pfizer did distrupt part of my body system

  32. Got the Pfizer 1st 2 shots no issues. Got the Booster 22 days ago and it’s really been a roller coaster. Day after booster tongue and lip numbness on left side took Benedryl, next morning same, then following Monday tongue swelling, throat felt like closing, all left sided with t lip numbness, got IV drugs and went back home.. for the next 4 days ER visits for the same issues. Was told by 1 Dr they saw Bells Palsy, got prednisone for that . Irregular heart beats, ringing in ears, weakness, tingling in hands and feet, just a general feeling of unwellness. Was fine before Booster. Waiting on an Allergist and Neurologist appt hopefully this will help shed some light.. oh had 2 CT and was told normal. I really don’t think the Dr’s know what to tell me or do for me. I have been told to take Pepcid and something like Benedryl as needed..

  33. I am 67 yrs old. Got my Pfizer booster shot one week ago. Day after I had headache and fever. Since then I keep getting headaches and intermittent fever throughout the day. I feel horrible. Could this be a reaction to booster after a week? If so, how long might I expect it to last

  34. Hi I just got my 2nd Pfizer booster on Monday. This is the worst I’ve felt after vaccines. It started on Tuesday, I had severe aching from head to toe, even in my ankles and feet. It feels like brain fog! I’m slurring words and can’t think right. I’m a rideshare driver and my eyesight is like when you go outside after having your eyes dilated. The sun is real bright. I’m tired and it’s even harder to walk. Had trouble today and yesterday walking. Was sick to my stomach this morning. I’m trying to think of all the side effects. My arm is sore on the vaccine sight.

  35. Had 2nd Pfizer booster 3 days ago, I have a sore throat, inflammation of the lymph nodes, dizziness, weird noises and ringing in my ears and severe tiredness and fatigue. I also have a deep cough that keeps me up at night.
    I had none of these symptoms with 1st booster.
    Feeling horrible. I am 96 yrs old. NO, I’am not making this up!

  36. I had my Pfizer booster shot four days ago. I was having no problems the first day of the shot. But had severe fever and aches in the body the following day. My armpit is swollen and still suffering from fever. I have red rash type things on the left side of my belly and lower back.
    I am worried as I am living in the tribal district of Khyber Pakhtunkhwa, Pakistan. Here the health facilities and advise are not the one that available in the Us.
    Some one please advise me what to do????

  37. I had my booster on Tuesday, everyday there has been something different with my body, tired, weak, nasty taste in my mouth, swollen right arm, large red bumps on my right breast, swelling and bumps under my skin in my left hand. My back seems to have pimples coming on it. I feel miserable.

  38. Had my Pfizer booster in November followed by dreadful painful rashes . Got to the point where my hands were so bad they skinned and even opening a door was extremely painful.
    Finally ( despite my Gps best efforts ) she has managed to get my various rashes under control and my hands are nearly clear .
    It says in this article that no allergic reactions have been notified………well now they definitely have .
    Another booster …….not a cat in bells chance !!

  39. WOW
    All this coments are very scary.
    I got my 2 pzfizer vaccines last year but after all this coments I ‘m very concern of the booster vaccines.
    A friend lawyer got her vaccines and got her heart raise.
    My G D I wonder about this boosters vax. Can they hurt you more that they can help you.

  40. After my booster shot and until now month ago body pains kills me..stiff neck, back pains and leg cramps. Hoping it will wear off for the next month or days. It is very disturbing.

  41. My husband and I got the second buster ( Pfizer) two weeks ago.
    Pain in knees, ankles, numbness in feet, muscles pain, lower back pain.
    Everyday is better and we hope it all goes away.
    Better than getting Covid and maybe surviving it, maybe not!

  42. I haven’t had any Pfizer jab, no Moderna jab, no Astra Zeneka jab, no Johnson & Johnson jab, no baby jabs at all, haven’t caught covid, am 52 and feel great

    • My brother in law was just like you Helen, except that he contracted Covid in Feb 2022 and his body was zipped up in a black plastic bag then incinerated 3 weeks later.
      I’ve had 5 Pfizer jabs. This last one caused injection point muscle pain and mild to severe aches in my joints for about 48 hours and then disappeared.

  43. I’m 73 years old male, 19 years out from a double lung transplant, Espogheal Cancer, and a stroke, and I’ve had all shots required plus all booster shots. Besides a sore arm for a few hours after the shot, nothing. Plus my wife and Daughter plus grandkids have had COVID and I stayed COVID Free.

  44. Am 55years old male. I had my Pfizer booster shot on Monday 29thAugust 2022. Apart from the usual side effects of joint pain,etc I experienced a chest pain after two days. The pain has persisted til now. Have taken some mild pain killers cataphlan and betaphyn but hasn’t improved. What could be the issue?

  45. I got 1st shot of pfizer booster August 8,2022. My body is tired, dizzy,my left chest and arms is pain,and also my back, short of breathing, sometimes i feel numb on my knee. And i lost weight

  46. I got 1st shot of pfizer booster August 8,2022. My body is tired, dizzy,my left chest and arms is pain,and also my back, short of breathing, sometimes i feel numb on my knee. Untill now i feel all of this And i lost weight. I hope i feel better soon

  47. My wife is 48 ,she had the 4th booster vaccines about a week ago and has pins and needles in her fingers and has diarrhoea for 2 days so far

  48. Got Pfizer booster vaccine in march in southafrica. Am back to kenya but Whenever I take a bath my whole body start to ich I get rushes then they disappear after an hour ..or whenever it’s cold my whole body start to ich and I scratch myself like hell ..oh my God I regret taking the 3 vaccine .

  49. I have experienced severe and constant itching all over from scalp to lower legs
    after receiving fourth Pfizer vacc,
    No rashes but a hive here and there.
    Feel like I am being pricked all over with needles.
    I was fine before this happened about 8 months ago. Tried antihistamines but no effect. Very debilitating when trying to sleep.
    I hope this is not permanent, my doctor doesn’t seem concerned. Seems like an allergic reaction, what can I do, any ideas anyone?


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