Drug Interactions, Kratom Guides

Can You Mix Kratom & Metronidazole (Flagyl)?

Metronidazole is an antibiotic commonly sold under the brand name Flagyl. Is it safe to take metronidazole and kratom at the same time? How do these two compounds interact?

Unfortunately, taking kratom and metronidazole simultaneously is not ideal and can actually be dangerous.

Here’s what we know about this combination and any dangers associated with it.

Written by Wade Paul
Last Updated 1 year ago

Wade Paul

Founder & Editor-In-Chief

Wade Paul is the founder and editor-in-chief at Kratom.org.

Does Kratom Interact With Metronidazole (Flagyl)?

Yes, kratom can interact negatively with metronidazole, leading to mild to moderate side effects.

These compounds aren’t dangerous on their own, but if you mix antibiotics and kratom, you could experience unwanted side effects.

Here’s how the interaction between kratom and metronidazole works:

Metronidazole Can Slow Down Kratom’s Metabolism (Metabolic Inhibition)

Most of the drugs we take are broken down (metabolized) in the liver by a group of enzymes known as the cytochrome P450 family (CYP).

Evidence shows metronidazole can inhibit the CYP3A4 enzyme [1, 2]. Kratom requires the CYP3A4 enzyme for its proper metabolization [3]. If you take these two substances together, metronidazole’s inhibiting effect over the CYP3A4 enzyme can slow down kratom’s metabolism, making it stay longer in the system than expected.

This can cause a buildup of kratom in the system (especially with repeated doses) and increases the risk of experiencing side effects like nausea, headaches, restlessness, constipation, and more.

Be extremely careful, and always talk to your doctor first. You’ll probably only be on metronidazole for seven days, so it’s best to avoid the risk of experiencing a negative interaction. 

Other related nitroimidazole antimicrobials that may interact with kratom include:

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

Is It Safe to Take Kratom With Metronidazole?

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

When taken together, kratom’s effects could last longer and become more potent, heightening your risk of experiencing side effects, including an overdose.

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

What is Metronidazole (Flagyl)?

Metronidazole is an antibiotic drug that became commercially available in 1960 [4]. Since then, it’s become one of the drugs listed on the World Health Organization’s List of Essential Medicines.

This drug can cause bacterial cell death by altering the DNA structure in susceptible organisms. The FDA has approved metronidazole for or the treatment of a broad range of infections, including intestinal amebiases, liver amebiasis, bone and joint infections, endocarditis, among others.

Metronidazole Specs

Trade NameFlagyl, Flagyl 375, Flagyl ER
ClassificationNitroimidazole antimicrobials
CYP MetabolismNone
Interaction with KratomMetabolic inhibition
Risk of InteractionMild to moderate

What is Metronidazole Used for?

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

It has additional off-label uses, including bite wound infections, Crohn’s disease, post-surgical resection management, perianal fistulas, periodontitis, and tetanus [4].

What Are the Side Effects of Metronidazole?

Like with most drugs, metronidazole treatment involves the possibility of experiencing 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 the following:

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

What is Kratom?

Kratom (Mitragyna speciosa) is an evergreen tree member of the coffee family native to Thailand, Indonesia, Malaysia, Myanmar, and Papua New Guinea.  Indigenous people in these regions have used kratom since the 19th century as a traditional medicine to combat pain and fatigue.

Other primary uses of kratom are increasing energy and relieving anxiety and insomnia, 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:

Kratom leaf and flower.

What’s The Dose of Kratom?

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

When you first take kratom, it’s wise to stay around 2 grams. We recommend you take note of how it affects you to adjust your dose for next time.

Taking occasional breaks is essential to avoid building a tolerance or becoming addicted.

General dosage guidelines for kratom include the following:

  • 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:

We also know that regular kratom use can cause dependence and addiction, hence the importance of following the dosage guidelines and taking regular tolerance breaks.

You should not take kratom while pregnant or breastfeeding, as the baby could also develop a dependence on the herb and experience withdrawal symptoms.

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. The effects are euphoric and energizing.
  2. Red Vein Kratom — Best for pain and sleep, fast-acting and potent. The 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.

Metronidazole could slow down kratom’s metabolism in the liver; using them together increases your risk of side effects or overdose.

The side 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.  


Further Reading