Drug Interactions, Kratom Guides

Can You Mix Kratom & Metronidazole (Flagyl)?

Metronidazole is an antibiotic; kratom has many uses, but, as far as we know, it’s not an antibiotic. How could these two possibly interact?

Unfortunately, they can, so using the two together is not ideal and can actually be dangerous.

Here’s what we know about metronidazole and kratom and any dangers associated with combining them.

Last updated 5 months ago by Wade Paul

Can You Mix Kratom & Metronidazole (Flagyl)?

Does Kratom Interact With Metronidazole (Flagyl)?

Kratom has a moderate chance of interacting negatively with metronidazole. Metronidazole belongs to the drug class nitroimidazole antimicrobials. 

On their own, they aren’t very dangerous, but if you mix antibiotics and kratom, you could experience unwanted side effects.

Metronidazole is possibly an inhibitor of CYP3A4 [1]. Kratom uses CYP3A4 during metabolization [2]. If you take these two substances together, you’ll be at risk of making metronidazole’s side effects worse.

Be extremely careful and always talk to your doctor first. You’ll probably only be on metronidazole for seven days but don’t take the risk of a negative interaction. 

Other, related nitroimidazole antimicrobials that kratom may interact with include:

  • Tinidazole
  • Nimorazole
  • Dimetridazole
  • Pretomanid
  • Ornidazole
  • Megazol
  • Azanidazole

Is It Safe to Take Kratom With Metronidazole?

No, it’s not safe to mix metronidazole with kratom.

When taken together, these two substances make each other stronger, heightening your risk of side effects, including an overdose.

Talk to your doctor to determine if this combo is right for you.

What is Metronidazole (Flagyl)?

Metronidazole first became commercially available in 1960. Since then, it’s become one of the drugs listed on the World Health Organization’s List of Essential Medicines.

In 2018, it reached number 119 of the most popular prescriptions in the US. There are more than 5 million US citizens taking metronidazole at any given time.

Metronidazole Specs

Trade NameFlagyl, Flagyl 375, Flagyl ER
ClassificationNitroimidazole antimicrobials
CYP MetabolismCYP3A4
Interaction with KratomInhibited metabolism
Risk of InteractionModerate to high

What is Metronidazole Used for?

Metronidazole is used as an antibiotic and can treat the reproductive system, gastrointestinal tract, skin, heart, bone, joint, lung, blood, and nervous system. Additionally, it can treat sexually transmitted diseases and bacterial vaginosis.     

What Are the Side Effects of Metronidazole?

Metronidazole can cause several side effects. It’s also important to remember that you should never take it to treat a cold, the flu, or any other viral infection. 

Common side effects of metronidazole may include:

  • Vomiting
  • Nausea
  • Diarrhea
  • Constipation
  • Upset stomach
  • Stomach cramps
  • Loss of appetite
  • Headache
  • Dry mouth
  • Sharp metallic taste
  • Mouth or tongue irritation
  • Numbness, pain, burning, or tingling in your hands or feet
  • Seizures
  • Rash
  • Itching
  • Hives
  • Peeling or blistering skin
  • Flushing
  • Stuffy nose, fever, or sore throat
  • Joint pain
  • Dizziness
  • Difficulty speaking
  • Problems with coordination
  • Confusion
  • Agitation

What is Kratom?

People have been using kratom (Mitragyna speciosa) since at least the 19th century; it’s been a part of traditional medicine in the area since. This member of the coffee family hails from Southeast Asia and is native to Thailand, Indonesia, Malaysia, Myanmar, and Papua New Guinea. 

Its primary use is increasing energy and relieving pain, especially among laborers in Southeast Asia. It also has a wide variety of other benefits, including reducing symptoms of opioid withdrawal.

What’s Kratom Used for?

Kratom is still used for medicinal purposes in Southeast Asia, but its popularity is spreading far and wide. Not only does it have numerous health benefits, but it’s also relatively safe and well-tolerated.  

Suggested health benefits of kratom include:

What’s The Dose of Kratom?

There is no specific kratom dose because kratom effects are so varied, and its users have different needs. However, a simple kratom dose calculator can help you get started.

When you first begin taking kratom, it’s wise to stay around 2 grams. Take note of how it affects you so you can adjust your dose for next time.

It’s important to take occasional breaks to avoid building a tolerance or becoming addicted.

General dosage guidelines for kratom include:

  • Low-Dose Kratom (2–6 grams of dried powder)
  • High-Dose Kratom (6–12 grams of dried powder)

Taking too much at a time increases your odds of dealing with side effects or an overdose.

What are the Side Effects of Kratom?

Kratom is generally well-tolerated, but this doesn’t mean you won’t possibly deal with some side effects.

Common side effects of kratom include:

  • Constipation
  • Dizziness
  • Anxiety
  • Brain fog
  • Cognitive impairment
  • Nausea
  • Vomiting
  • Sedation
  • Lethargy

What Are the Different Types of Kratom?

Kratom comes in a wide variety of strains. Each of these strains belongs to one of four classes: white, red, green, or yellow.

Here’s a quick run-down of the different kratom strain classes:

  1. White Vein Kratom — Best for concentration, focus, and energy. Effects are euphoric and energizing.
  2. Red Vein Kratom — Best for pain and sleep, fast-acting and potent. Effects are numbing and relaxing.
  3. Green Vein Kratom — Balanced between white and red (sedating and stimulating).
  4. Yellow Vein Kratom — Made from white kratom and other strains. Effects cover all ranges of the spectrum (sedating or stimulating).

Key Takeaways: Is it Safe to Mix Kratom & Metronidazole (Flagyl)?

Metronidazole and kratom should not be used together.

Kratom could make metronidazole metabolize slower; using them together increases your risk of side effects or overdose.

If you’re taking metronidazole and would like to take kratom at the same time, be sure to speak to your doctor first.

The effects of taking metronidazole and kratom together can worsen the longer you do it. It’s best not to mix them at all; however, talking to your doctor can prevent you from having any issues.  


  1. Roedler, Rhonda & Neuhauser, Melinda & Penzak, Scott. (2007). Does Metronidazole Interact with CYP3A Substrates by Inhibiting Their Metabolism Through This Metabolic Pathway? Or Should Other Mechanisms Be Considered?. The Annals of pharmacotherapy. 41. 653-8. 10.1345/aph.1H401.
  2. Kamble, S. H., Sharma, A., King, T. I., León, F., McCurdy, C. R., & Avery, B. A. (2019). Metabolite profiling and identification of enzymes responsible for the metabolism of mitragynine, the major alkaloid of Mitragyna speciosa (kratom). Xenobiotica, 49(11), 1279-1288.