Do Antibiotics Weaken Your Immune System?

Antibiotics are some of the most commonly prescribed medications and are taken to treat bacterial infections. This makes them imperative for your body’s health, but can they also weaken your immune system?

As medication that kills and destroys bacteria, antibiotics can also affect the good bacteria in your body. This good bacteria has many responsibilities, including its role in your immune system. As such, taking antibiotics can weaken your immune system and make it less effective. 

Continue reading to learn why we still take antibiotics, when they are not recommended, and how to boost your immune system while on antibiotics. 

Table of Contents

What Are Antibiotics, and What Are They Used For?

Antibiotics are a type of medication used to treat bacterial infections. They can come as pills, liquid suspensions, ointments/creams, or IV infusions. Most antibiotics are only available as a prescription, but some topical creams can be purchased over the counter. 

Since antibiotics target bacteria, they cannot treat viral or fungal infections. 

Some infections that antibiotics may be used to treat include:

  • urinary tract infections (UTIs)
  • strep throat
  • E. coli
  • acne
  • bronchitis
  • sexually transmitted diseases (STDs)
  • skin infections
  • upper respiratory tract infection
  • ear infection
  • conjunctivitis (pink eye)
  • eye infections
  • gum disease
  • meningitis

There are hundreds of different antibiotics, which vary based on their mechanism of action and, thus, the infections they treat.

How Do Antibiotics Work?

How antibiotics treat bacterial infections varies based on the type of antibiotic, also known as the antibiotic class. 

Some of the most commonly prescribed antibiotic classes include:

  • tetracyclines
  • penicillin
  • quinolones
  • cephalosporins
  • macrolides
  • lincomycins
  • aminoglycosides
  • sulfonamides
  • carbapenems
  • glycopeptides

The class encompasses a group of antibiotics with similar chemical and pharmacologic properties. Because of this, many antibiotics within the same class kill the same or similar bacteria. 

How antibiotics attack an infection varies between classes. Some antibiotics kill the bacteria directly, while others prevent it from growing and multiplying by interfering with protein production or decreasing the bacteria’s cell wall integrity. 

Do Antibiotics Weaken Your Immune System?

Antibiotics have become a staple of treating bacterial infections, and when you feel sick, it’s common to go to the doctor in search of an antibiotic. This is because the antibiotic helps to attack the bacteria, aiding your immune system in negating the infection. 

Knowing how antibiotics work, it is common to think they only benefit the immune system. However, there is a downside to be aware of. 

As we know, antibiotics kill bacteria, which is good in the case of bacterial infection. However, you naturally have bacteria throughout your body, with some of the most diverse areas being the gut, mouth, and (in women) the vagina. These areas of the body rely on good bacteria to function correctly and even to prevent infections from occurring, but this is where antibiotics can interfere. 

How Can Antibiotics Weaken Your Immune System?

When you take an antibiotic, it gets rid of the bacteria causing your infection, but it may also attack the good bacteria in your body. 

One of the roles of this bacteria, specifically the bacteria in the gut, is to support your immune system. So, when antibiotics kill the good bacteria, they can harm your immune system and weaken it. This is especially noticeable when taking antibiotics for illnesses that they are not meant to treat.

Antibiotics are intended only for cases when you are ill with a bacterial infection, not a virus or fungus. If you take antibiotics when you have a virus-related illness, you can suffer from a depressed immune system, worsening your illness as your body’s immune system cannot work to remove the infection. In the cases of viruses, their removal often relies entirely on your body’s immune system, so taking an antibiotic is not only ineffective, but it can also result in you having a longer-lasting or more severe illness.

A problem with this is that some illnesses may result from both a virus or bacteria. For example, strep throat, bronchitis, and pneumonia can all result from a virus or bacteria, yet only cases resulting from bacteria will benefit from antibiotics. Otherwise, taking antibiotics will not only be ineffective against your illness, but by suppressing your immune system it may make your infection worse.

How Can You Strengthen Your Immune System?

As we know, antibiotics can harm the good bacteria in your gut, but you can help to counteract this effect by taking probiotic shots while on antibiotics. The probiotic shots help replenish the good gut bacteria, helping your body’s natural immune system stay strong. 

Other supplements may help strengthen the immune system, such as vitamin C, elderberry, echinacea, and zinc. Research has shown that these supplements may help improve the immune system, which can help counteract the effects of antibiotics. 

Even more, some of these supplements may also help fight viruses because they help improve the immune system. For example, echinacea and elderberry exhibit antiviral properties in research studies. Elderberry, in particular, blocks the proteins viruses need to enter cells and can keep infected cells from releasing the virus. 

Elderberry also works with Vitamin C by helping your body absorb it better, and by contributing to the immune system, Vitamin C can then help improve it. 


Do antibiotics suppress your immune system?

Antibiotics can suppress your immune system by depleting the amount of good bacteria in your body, which play a role in the body’s immune system. When taking antibiotics, these bacteria may also be attacked, which can make your immune system less effective. Generally, this is only a concern when taking antibiotics for illnesses not bacterial in nature because the antibiotic cannot fight the infection, and taking it suppresses the immune system.

Do antibiotics make you more susceptible to getting sick?

Taking antibiotics can suppress the immune system, which may make you more susceptible to getting sick. This is because the immune system is responsible for finding and removing foreign invaders before they can cause an infection. If your immune system is suppressed and you are introduced to a foreign invader, it may become an infection. However, antibiotics do not introduce these foreign invaders into your body, they only suppress your immune system. 

Key Takeaways

Antibiotics are a key prescription medication used to treat bacterial infections. However, because they attack bacteria, they can also attack the good bacteria that naturally reside in the body and play an essential role in the immune system. As such, antibiotics can weaken the immune system.

When treating a bacterial infection, this is often not a concern as the benefits offered by antibiotics outweigh the temporary suppression. However, if you take antibiotics for a viral infection, which they cannot treat, you then suppress your immune system and may experience a longer and more severe infection.

If you take antibiotics, there are supplements you can take to boost your immune system, such as probiotics, elderberry, echinacea, zinc, and vitamin C. 


Content on the DrHouse website is written by our medical content team and reviewed by qualified MDs, PhDs, NPs, and PharmDs. We follow strict content creation guidelines to ensure accurate medical information. However, this content is for informational purposes only and not a substitute for professional medical advice, diagnosis, or treatment. For more information read our medical disclaimer.

Always consult with your physician or other qualified health providers about medical concerns. Never disregard professional medical advice or delay seeking it based on what you read on this website.

If you are experiencing high fever (>103F/39.4C), shortness of breath, difficulty breathing, chest pain, heart palpitations, abnormal bruising, abnormal bleeding, extreme fatigue, dizziness, new weakness or paralysis, difficulty with speech, confusion, extreme pain in any body part, or inability to remain hydrated or keep down fluids or feel you may have any other life-threatening condition, please go to the emergency department or call 911 immediately.



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