Herb & supplement monograph

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

But these pages have grown well beyond that into a full monograph — what Bulbine Natalensis 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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Bulbine Natalensis 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 Bulbine Natalensis drug interaction appears low for most people, mainly because no interaction has been confirmed in human studies. Every listed interaction is rated moderate rather than major, and all of them rest on lab or animal research, not on documented problems in people.

Interactions deserving the most attention

The combinations we would watch most closely involve blood thinners and digoxin. Lab research suggests the leaf may reduce platelet clumping, which could add to the bleeding risk of anticoagulant or antiplatelet drugs. Digoxin has a narrow safety margin, and the stem may contain natural chemicals similar to it, though it is unclear whether the amounts matter. Because animal studies show the stem can raise testosterone levels, adding it to testosterone therapy could theoretically increase side effects.

What the rest of the list means

The long list exists mostly because lab studies suggest the stem may affect enzymes and a transporter the body uses to process many medications, which sweeps hundreds of drugs into the count. None of these predicted effects has been studied in humans, so most combinations are flagged as a precaution rather than a proven problem.

Check your medications against Bulbine Natalensis

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

Interaction report

Drugs that interact with Bulbine Natalensis

920 medications have a known interaction with Bulbine Natalensis, 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 Bulbine Natalensis using our pharmacist-reviewed interaction data.

AI summaries are generated from our Bulbine Natalensis 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 Bulbine Natalensis 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 Bulbine Natalensis affects

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

All 7 drug categories Bulbine Natalensis interacts with

Anticoagulant/antiplatelet DrugsCytochrome P450 1a2 (cyp1a2) SubstratesCytochrome P450 2c9 (cyp2c9) SubstratesCytochrome P450 3a4 (cyp3a4) SubstratesDigoxin (lanoxin)P-glycoprotein SubstratesTestosterone

Anticoagulant/Antiplatelet Drugs

Theoretically, combining Bulbine natalensis leaf with drugs that have anticoagulant or antiplatelet activity might increase the risk of bruising and bleeding.
In vitro research shows that Bulbine natalensis ground leaf extract inhibits platelet aggregation.

Likelihood Possible Evidence D

Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, Bulbine natalensis stem might reduce the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that Bulbine natalensis stem extract slightly induces CYP1A2 mRNA expression and enzyme activity. Theoretically, this may increase the metabolism of CYP1A2 substrates; however, this has not been studied in humans.

Likelihood Possible Evidence D

Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, Bulbine natalensis stem might reduce the levels and clinical effects of CYP2C9 substrates.
In vitro research shows that Bulbine natalensis stem extract induces CYP2C9 mRNA expression and enzyme activity. Theoretically, this may increase the metabolism of CYP2C9 substrates; however, this has not been studied in humans.

Likelihood Possible Evidence D

Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, Bulbine natalensis stem might reduce the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that Bulbine natalensis stem extract induces CYP3A4 mRNA expression and enzyme activity. Theoretically, this may increase the metabolism of CYP3A4 substrates, but this has not been studied in humans.

Likelihood Possible Evidence D

Digoxin (Lanoxin)

Theoretically, Bulbine natalensis stem might increase the risk of adverse effects and toxicity when taken with digoxin.
Bulbine natalensis stem may contain cardiac glycosides, although it is unclear if these chemicals are present in clinically relevant concentrations.

Likelihood Possible Evidence D

P-Glycoprotein Substrates

Theoretically, Bulbine natalensis stem might increase the levels and clinical effects of p-glycoprotein substrates.
In vitro research shows that Bulbine natalensis stem extract induces p-glycoprotein mRNA expression; however, effects on transporter expression were not evaluated.

Likelihood Possible Evidence D

Testosterone

Theoretically, using Bulbine natalensis stem with testosterone replacement therapy might increase the risk of adverse effects.
Animal research shows that Bulbine natalensis stem can increase testosterone levels.

Likelihood Possible Evidence D

Monograph

Bulbine Natalensis: Uses, Safety & Side Effects

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

The bottom line

Bulbine natalensis is a South African plant marketed mainly as a testosterone-boosting and libido supplement, but the human evidence is essentially absent and most claims come from animal studies. Animal research has also raised concerns about possible liver and kidney harm at higher doses, so caution is warranted. Talk to your pharmacist or doctor before trying it.

Scientific name: Bulbine natalensis
Family: Asphodelaceae
Part used: Roots and stems (sometimes leaves)
Common forms: Capsules, powder, extracts

People commonly use it for

Boosting testosterone
Improving libido
Muscle building and athletic performance
General male vitality

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

Safety at a glance

OverallUse caution

Human safety data are lacking, and animal studies suggest possible liver and kidney toxicity at higher doses.

PregnancyPossibly Unsafe

When used orally in large amounts. Animal research shows that Bulbine natalensis stem extract might be embryotoxic when administered at a dose of 100...

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

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.

Jump to a section

Overview

Bulbine natalensis is a succulent flowering plant native to southern Africa, especially South Africa. It belongs to the same plant family as aloe. Traditionally, parts of the plant have been used in folk medicine for various purposes, including wound care and other ailments.

Today, the plant is sold mostly as a dietary supplement marketed to men. Product labels often promise higher testosterone, more energy, better libido, and improved muscle building. Most of this marketing is based on animal experiments rather than studies in people.

How it works

The plant contains natural compounds such as saponins, alkaloids, and other plant chemicals that researchers believe may influence hormones. In rodent studies, extracts appeared to affect testosterone levels and reproductive behavior.

The exact way it might work is not well understood, and these proposed mechanisms come mostly from laboratory and animal research. We do not have good human data confirming any hormone-related effects.

Effectiveness

Does Bulbine Natalensis work?

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

Evidence overview · 11 uses evaluated

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

Also studied for 11 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Diabetes