Herb & supplement monograph

Guava Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Guava interacts with medications. The heart of this page is the interaction list — every drug Guava is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Guava is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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On this page

Guava Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Guava drug interaction appears low for most people. None of the listed interactions are rated major, and the single concern behind them all comes from animal research rather than human studies.

Interactions deserving the most attention

The one area worth watching is diabetes medications, such as glimepiride and glyburide. Animal studies suggest guava leaf extract or the fruit may lower blood sugar, so combining it with these medicines could, in theory, add up and push blood sugar too low. Because blood sugar is a closely monitored value, people taking these medicines should keep an eye on their readings while using guava regularly.

What the rest of the list means

Although the list of interacting medications looks long, it really reflects one theme: the many different drugs used to treat diabetes. The concern is theoretical, based on possible additive blood-sugar effects seen in animals, and has not been confirmed to cause meaningful problems in people. A long list here does not mean guava is risky with most medicines.

Check your medications against Guava

Based on HelloPharmacist’s Guava interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Guava

86 medications have a known interaction with Guava, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Guava using our pharmacist-reviewed interaction data.

AI summaries are generated from our Guava interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Guava combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Guava affects

Every type of medication (drug category) Guava is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 1 drug category Guava interacts with

Antidiabetes Drugs

Theoretically, concomitant use with antidiabetes drugs might have additive effects and increase the risk of hypoglycemia. Animal research shows that guava leaf extract or guava fruit can have hypoglycemic effects. Monitor blood glucose levels closely. Medication dose adjustments may be necessary. Some antidiabetes drugs include glimepiride (Amaryl), glyburide (Diabeta, Glynase PresTab, Micronase), insulin, metformin, pioglitazone (Actos), rosiglitazone (Avandia), and others.

Likelihood Possible Evidence D

Monograph

Guava: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

Guava is a tropical fruit tree whose leaves and fruit have a long history of folk use for diarrhea, blood sugar, and general wellness. The fruit is a nutritious food rich in vitamin C, but evidence for guava leaf supplements treating specific health conditions is limited and mostly early. If you want to try guava leaf products, talk with your pharmacist or doctor first, especially if you take medicines or have a health condition.

Scientific name: Psidium guajava
Family: Myrtaceae
Part used: Leaves, fruit, and bark
Common forms: Tea, capsules, leaf extract, fresh fruit, juice, powder

People commonly use it for

Diarrhea and digestive upset
Blood sugar support
Cholesterol support
Wound and skin care
Cough and sore throat

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Guava fruit is generally safe as a food, but leaf extracts and supplements are less studied.

PregnancyUse caution

Guava fruit as a food is fine, but concentrated leaf supplements are not well studied and are best avoided.

BreastfeedingLikely Safe

When guava fruit is consumed as food. There is insufficient reliable information available about the safety of guava fruit or leaf when used for medic...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Guava (Psidium guajava) is a small tropical tree that produces a sweet, green-to-yellow fruit. It grows in warm regions across Central and South America, the Caribbean, Africa, and Asia.

The fruit is eaten fresh or made into juice, and it is a good natural source of vitamin C, fiber, and other nutrients. Beyond the fruit, the leaves and bark have been used in traditional medicine for many years. People often brew guava leaves into a tea or take them as capsules or extracts.

Today, guava leaf is sold as a dietary supplement marketed for digestion, blood sugar, and general health. It is important to know that being popular or traditional does not mean a use is proven.

How it works

Guava leaves and fruit contain compounds such as flavonoids (including quercetin), tannins, polyphenols, and vitamin C. These act as antioxidants, which means they may help protect cells from a type of damage called oxidative stress.

In laboratory and animal studies, guava leaf compounds appear to slow the growth of certain microbes, affect how the gut moves, and influence how the body handles sugar and fats. The tannins in the leaves may be part of why guava is traditionally used for diarrhea.

It is important to remember that most of this evidence comes from test-tube and animal research. What happens in a lab does not always happen the same way in the human body.

Effectiveness

Does Guava work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 17 uses evaluated

17 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

For Guava, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 17 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Cancer