Herb & supplement monograph

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

But these pages have grown well beyond that into a full monograph — what Hemp 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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Reviewed by licensed pharmacists Sourced from Natural Medicines

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Hemp 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 Hemp drug interaction appears low for most people. None of the listed interactions are rated major, and the great majority are minor and supported only by lab or animal research.

Interactions deserving the most attention

The pairing that stands out most is with estrogens, because animal research suggests hemp may have hormone-like effects that could interfere with hormone therapy; this is the only moderate-rated interaction, and it has not been confirmed in people. Theoretical concerns have also been raised with blood thinners and blood pressure medications, but human studies of hemp seed oil found no meaningful effect on platelet clumping or blood pressure. We see these as reasons for awareness, not alarm.

What the rest of the list means

Many medications appear on this list mainly because lab research suggests hemp might speed up enzymes the body uses to clear certain drugs, which could in theory lower their levels. Findings like these often do not translate into real-world problems, and several of hemp's predicted effects have already failed to appear when studied in people.

Check your medications against Hemp

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

Interaction report

Drugs that interact with Hemp

940 medications have a known interaction with Hemp, 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 Hemp using our pharmacist-reviewed interaction data.

AI summaries are generated from our Hemp 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 Hemp 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 Hemp affects

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

All 6 drug categories Hemp interacts with

EstrogensAce Inhibitors (aceis)Anticoagulant/antiplatelet DrugsAntihypertensive DrugsCytochrome P450 1a2 (cyp1a2) SubstratesCytochrome P450 3a4 (cyp3a4) Substrates

Estrogens

Theoretically, hemp might interfere with hormone therapy due to its estrogenic effects.
In an ovariectomized animal model, a diet containing hemp seed 1%, 2%, or 10% resulted in normalized plasma levels of 17-beta-estradiol. The mechanism of action for this effect is unclear.

Likelihood Possible Evidence D

Ace Inhibitors (Aceis)

Theoretically, consuming hemp seed protein isolate with ACE inhibitors might have additive effects and increase the risk of hypotension.
Hemp seed protein hydrolysate has shown ACE inhibitor-like effects in a hypertensive animal model. However, hempseed oil consumption does not seem to reduce blood pressure in humans. Until more is known, monitor blood pressure and potassium levels.

Likelihood Unlikely Evidence D

Anticoagulant/Antiplatelet Drugs

Theoretically, hemp seed might increase the risk of bleeding when used concomitantly with anticoagulant/antiplatelet drugs.
In animal research, hemp seed at 5% of the diet inhibits platelet aggregation in vitro. However, in human research, taking hemp seed oil 2 grams daily for 12 weeks does not inhibit the aggregation of platelets in vitro.

Likelihood Possible Evidence D

Antihypertensive Drugs

Theoretically, hemp seed protein may have additive effects with antihypertensive drugs.
In a hypertensive animal model, hemp seed protein hydrolysate reduced systolic blood pressure by a mechanism possibly involving the inhibition of renin and angiotensin converting enzyme (ACE) activities. However, there was no effect of hemp seed protein on blood pressure in normotensive animals. Furthermore, hempseed oil consumption does not seem to reduce blood pressure in humans.

Likelihood Unlikely Evidence D

Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, hemp might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that hemp induces CYP1A2 enzymes.

Likelihood Possible Evidence D

Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, hemp might decrease the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that hemp induces CYP3A4 enzymes.

Likelihood Possible Evidence D

Monograph

Hemp: Uses, Safety & Side Effects

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

The bottom line

Hemp seeds and hemp seed oil are nutritious foods rich in protein, fiber, and healthy omega-3 and omega-6 fatty acids, and they are generally safe for most people as part of the diet. While the nutrition is real, strong human evidence that hemp supplements treat specific medical conditions is limited. Talk with your pharmacist or doctor before using hemp products for a health concern, especially if you are pregnant or breastfeeding.

Scientific name: Cannabis sativa
Family: Cannabaceae
Part used: Seeds (hemp hearts), seed oil, protein powder, and sometimes leaves and extracts
Common forms: Hemp seeds (hearts), hemp seed oil, hemp protein powder, capsules, and food products

People commonly use it for

Plant-based protein source
Heart health support
Skin and hair health
Reducing inflammation
General nutrition (omega fatty acids)

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

Safety at a glance

OverallUse caution

Hemp seed foods are generally well tolerated, but concentrated extracts and supplements are less studied.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using.

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.

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Overview

Hemp comes from the plant Cannabis sativa, the same species as marijuana. However, hemp is a different variety grown to contain very little THC, the compound that causes a "high." Because of this, hemp seeds and seed oil are used mainly as foods and nutritional supplements rather than for any mind-altering effect.

Hemp has been grown for thousands of years for its strong fibers, used to make rope, cloth, and paper. Today the plant is also valued for its seeds, which are sometimes called hemp hearts. These seeds are pressed to make oil or ground into protein powder.

People commonly use hemp seeds and hemp oil to add protein, fiber, and healthy fats to their diet. You can find hemp in foods, drinks, capsules, powders, and skin care products.

How it works

Hemp seeds are rich in polyunsaturated fatty acids, including alpha-linolenic acid (an omega-3) and linoleic acid (an omega-6). These healthy fats are building blocks the body uses for cell membranes and may help support normal cholesterol levels and reduce inflammation.

The seeds also provide complete protein, fiber, and minerals such as magnesium and zinc, plus plant antioxidants. These nutrients support general health when hemp is part of a balanced diet.

Most of the proposed benefits beyond basic nutrition come from laboratory or animal studies. It is not yet clear how strongly these effects carry over to people in everyday use.

Effectiveness

Does Hemp 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 Hemp, 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 Atopic dermatitis (eczema)