Herxheimer Reaction - What is it and How to Manage?

July 7, 2023

Have you ever gotten sick, and then went to a doctor who gave you just the right medicines to make you feel better, but you actually got worse before you got better? Two independent dermatologists in the late 1800s and early 1900s observed their patients’ symptoms worsen after starting treatments with a mercurial compound and studied the phenomenon which went on to be called the ‘Jarisch-Herxheimer Reaction’ (JHR), popularly called the Herxheimer reaction or the Herx reaction or “herxing”. 

What is the Herx Reaction?

The Herx reaction is a temporary reaction that is triggered by an exorbitant number of endotoxins in the bloodstream. Endotoxins and glycoconjugates are harmful substances that are released by harmful microorganisms and bacteria when they are destroyed by an antibiotic or a kill agent in general [1].

In the process of the death of harmful microbes two significant events happen – a) the breaking down of biofilm, and b) the release of toxic substances commonly called endotoxins, and glycoconjugates. 

  1. Breaking down of biofilm: Biofilms are protective layers formed around colonies of harmful colonies of pathogenic microbes – bacteria, fungi, yeast, etc. The key function of the biofilm is to act as a protective layer for pathogens by enabling resistance against good bacteria and antibiotics. Within the biofilm, the pathogens proliferate and thrive in a low-oxygen environment, accumulating metabolic by-products and waste. When the biofilm is broken down by a kill agent, the pathogens are released into the GI tract, along with the metabolic waste and toxins [2]
  2. Release of toxic substances: When the individual cell membranes of each of the microorganisms break down, various toxins from within the cells get released into the GI tract. 

The release of these toxins triggers the immune system to respond with an acute and temporary inflammatory response. Your immune system starts working overtime to kill the harmful microbes and get rid of the toxins from the bloodstream and the GI tract to avoid any infections from occurring. This response can worsen the existing set of symptoms, and even result in the development of new symptoms. The level of exacerbation of symptoms is often an indicator of the height of the immune response. 

Symptoms of a Herx reaction:

While there is no definitive set of symptoms associated with the Herx reaction, here are some commonly observed symptoms - 

  1. bloating
  2. brain fog
  3. chills
  4. fever
  5. muscle aches
  6. weakness
  7. fatigue
  8. decrease in blood pressure
  9. headaches
  10. nausea
  11. skin lesions

The sudden worsening of symptoms, even though it may cause one to feel that the severity of their condition has worsened, is actually an indicator that the treatment or protocol is working effectively. 

How long does the Herx reaction last?

Although a temporary reaction, the duration of the Herx reaction is subject to several factors of the individual such as the condition being treated, the severity of the condition, the health of the immune system, degree of exposure to external toxins, lifestyle – including food consumption, sleep, exercise, etc. 

What causes the Herx reaction?

While the Herx reaction is very common with anti-biotic-based treatments for Lyme disease, Syphilis, Leptospirosis, etc. it has also been observed in the following cases when you - 

  1. switch to eating clean – getting rid of sugar, and processed foods that feed harmful microbes,  which eventually results in the death of the harmful microbes. 
  2. start a protocol of anti-microbial, anti-parasitic, and/or anti-fungal supplements. For example, herbs such as oregano, cinnamon, garlic, neem, dandelion, grapeseed extract, etc. that can destroy harmful microbes. 
  3. introduce or increase the consumption of probiotics, which can effectively outnumber harmful microbes and kill them. 

Managing a Herx reaction

Although the Herx reaction is unavoidable, there are ways to reduce the intensity of the Herx reaction without disturbing the efficacy of the treatment. 

  1. Increased fluid intake: Drinking plenty of fluids helps the system to better eliminate toxins released into the bloodstream and thus reduce the intensity of the Herx reaction. Water is a great choice, but a better choice would be fresh ginger tea which is rich in anti-inflammatory agents and can combat the body’s inflammatory response [3]. Hydration also helps support the proper functioning of the liver and kidneys, which can boost detoxification. 
  2. Anti-inflammatory herbs: Consumption of anti-inflammatory herbs under the guidance of a functional medicine practitioner can help reduce systemic inflammation. Herbs such as Turmeric, Chlorella, and Boswellia are loaded with excellent anti-inflammatory properties and can help reduce painful Herx symptoms. Turmeric, in particular, has demonstrated proven anti-inflammatory effects against multiple pro-inflammatory cytokines that are associated with the Herx reaction [4]
  3. Sleep: There is absolutely no better remedy than sleep when it comes to the restoration of your body. When you sleep, your body performs a lot of biological processes that help detox and restore your body that it cannot accomplish while awake. When you get enough rest by means of sleep, your body is also able to manage systemic inflammation by a reduction in the number of pro-inflammatory factors. 
  4. Gastrointestinal binders: Gastrointestinal binders are agents that can help the elimination of toxins released during the die-off of microbes. These can help reduce the degree of Herx reaction as well as the duration of the Herx reaction. A very commonly used binder is activated charcoal which can remove toxins and clear the detox pathways, thus enhancing detoxification [4]. Note that gastrointestinal binders should only be used under the supervision of a functional medicine practitioner. 

While Herxing is a natural response to the destruction of harmful microbes in the body, it is very important to be cognizant of the intensity of the Herx reaction. An extremely intense reaction can be detrimental to certain primary functions of the body and should be given immediate medical attention. If you or someone you know is experiencing Herxing, make sure to talk to a functional medicine practitioner to understand and identify a good protocol that will help ease the symptoms of Herxing. 


  1. https://www.ncbi.nlm.nih.gov/books/NBK557820/
  2. https://www.nature.com/articles/npjbiofilms20155
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4440027/ 
  4. https://sphinxsai.com/CTVOL4/ct_pdf_vol_4/CT=10%20%20(859--864).pdf

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