Are there any side effects from taking hemp seed oil?

November 13, 2025 •

4 min read

According to a 2018 randomized, single-blind crossover study, dietary hemp seed oil improved symptoms of atopic dermatitis, or eczema, after 20 weeks. While its benefits are often lauded, it is important to know if there are any side effects from taking hemp seed oil, and how to use it responsibly.

Quick Summary

Hemp seed oil is generally well-tolerated, but potential side effects include mild digestive upset, blood thinning properties, and rare allergic reactions. Individuals on specific medications or with certain health conditions should consult a doctor due to potential interactions. Side effects are often linked to dosage.

Key Points

Digestive Upset: Excessive consumption of hemp seed oil can lead to diarrhea, nausea, and stomach cramps due to its high fatty-acid content.
Drug Interactions: Hemp seed oil can interact with blood thinners and blood pressure medications, increasing the risk of bleeding or causing blood pressure to drop too low.
Potential for Fatigue: Some users report drowsiness or fatigue, especially when first starting, which can be managed by taking the oil in the evening.
Allergy Risk: Though rare, allergic reactions can occur, with symptoms ranging from skin rashes to swelling. A patch test is recommended for topical use.
Dose Dependent Effects: Most side effects, particularly digestive ones, are dose-dependent. Starting with a low amount and gradually increasing it is a key safety measure.
Not for Everyone: Individuals who are pregnant or breastfeeding, children, and those on specific medications should use caution or consult a doctor before use.

Understanding the Differences: Hemp Seed Oil vs. CBD Oil

Before diving into the side effects, it's crucial to distinguish between hemp seed oil and CBD oil, as they come from different parts of the Cannabis sativa plant and have different compositions.

Hemp Seed Oil: This oil is produced by cold-pressing the seeds of the hemp plant. It is rich in omega-3 and omega-6 fatty acids, along with vitamins and minerals. It contains negligible amounts of cannabinoids like THC and CBD, and therefore, it is not psychoactive. Its effects are purely nutritional.
CBD Oil: This oil is extracted from the leaves, flowers, and stalks of the hemp plant, where the concentration of CBD is highest. While CBD oil is also non-intoxicating, it works by interacting with the body's endocannabinoid system to produce therapeutic effects, which can have a wider range of side effects and drug interactions.

Common Side Effects of Hemp Seed Oil

For most people, hemp seed oil is very safe, especially when consumed in moderation. However, some mild, temporary side effects can occur, particularly when starting a new regimen or taking large quantities. The most commonly reported issues are digestive in nature.

Digestive Discomfort

Due to its high fatty-acid content, excessive consumption of hemp seed oil can cause gastrointestinal distress. Symptoms may include:

Diarrhea or loose stools
Nausea and stomach cramps
Bloating or gas

To prevent this, experts recommend starting with a small dose and gradually increasing it as your body adjusts. Taking the oil with food can also help minimize these effects.

Fatigue and Drowsiness

Some individuals have reported feeling fatigued or drowsy after taking hemp seed oil. This effect can be a benefit for those seeking better sleep, but for others, it can interfere with daily activities and alertness. If you experience this, consider taking the oil in the evening rather than the morning.

More Significant Side Effects and Precautions

While less common, some side effects are more significant and require a cautious approach, especially for individuals with pre-existing health conditions or those taking specific medications.

Potential Drug Interactions

Hemp seed oil has the potential to interact with certain medications, primarily due to its effect on blood clotting and blood pressure. It is crucial to consult a healthcare provider if you are taking any of the following:

Blood Thinners (Anticoagulants): Hemp oil contains compounds that may inhibit platelet aggregation and slow blood clotting. When combined with prescription blood thinners like warfarin, this can increase the risk of bruising and bleeding.
Blood Pressure Medications: The omega-3 and omega-6 fatty acids in hemp oil may help lower blood pressure. For individuals already taking medication for hypertension, this could cause blood pressure to drop too low, leading to dizziness or fainting.
Liver-Metabolized Drugs: Hemp, especially if cross-contaminated with other cannabis compounds, can affect liver enzymes responsible for drug metabolism. This may alter the effectiveness or side effects of certain medications.

Allergic Reactions

Although rare, allergic reactions to hemp seed oil can occur, especially in individuals with known allergies to plants in the Cannabaceae family. Symptoms can range from mild skin rashes to more severe reactions. It is always wise to perform a patch test before topical use and start with a very small dose orally to monitor for any adverse reactions.

Impact on Hormone-Sensitive Conditions

Some sources suggest that the gamma-linolenic acid (GLA) in hemp oil may have mild estrogenic effects, which could potentially interfere with hormone therapies or exacerbate hormone-sensitive conditions like breast cancer or endometriosis. This is a more complex issue, and those with such conditions should discuss the use of hemp oil with a healthcare professional.

Safe Usage and Who Should Be Cautious

To minimize the risk of side effects, it is recommended to start with a low dose, such as 1 to 2 teaspoons daily, and monitor your body's response. People in certain groups should be especially cautious:

Pregnant or Breastfeeding Women: Due to a lack of reliable safety information, it is best to avoid use.
Children: While generally considered safe, some rare cases of side effects like sleepiness and liver problems have been reported with hemp seed oil use in children. A doctor should be consulted.
Individuals Awaiting Surgery: Because hemp seed oil may slow blood clotting, it is recommended to stop taking it at least two weeks before a scheduled surgery.

Comparison: Hemp Seed Oil vs. CBD Oil Side Effects


Aspect	Hemp Seed Oil	CBD Oil
Source	Cold-pressed hemp seeds	Leaves, flowers, and stalks of hemp
Active Compounds	Primarily omega-3/6 fatty acids, vitamins	Concentrated cannabidiol (CBD)
Psychoactive Risk	None, contains negligible THC/CBD	None, but can contain trace THC (<0.3%)
Common Side Effects	Digestive issues, fatigue, dry mouth	Dry mouth, fatigue, nausea, diarrhea, appetite changes
Medication Interactions	Potential with blood thinners, BP meds	More significant potential interactions, especially liver-metabolized drugs
Overdose	Excessive intake can cause digestive upset and calorie weight gain	Can increase intensity of side effects like fatigue or sedation

Conclusion

While generally safe and well-tolerated, side effects from taking hemp seed oil are a possibility, particularly with high doses or in sensitive individuals. The most common side effects are mild digestive issues, which can often be mitigated by adjusting the dose. More significant concerns, such as interactions with blood-thinning medication or blood pressure drugs, require careful consideration and consultation with a healthcare professional. Unlike CBD oil, hemp seed oil carries no psychoactive risk, but it's essential to understand its distinct safety profile. By starting low, monitoring your body, and seeking medical advice when needed, you can minimize risks while potentially enjoying the nutritional benefits of hemp seed oil.

For more detailed health information, consult a reliable medical resource such as WebMD.

Frequently Asked Questions

Yes, consuming excessive amounts of hemp seed oil can cause an upset stomach, nausea, or diarrhea due to its high fat content. It is recommended to start with a small dosage and gradually increase it.

Yes, hemp seed oil can interact with certain medications. It has mild anticoagulant properties and can affect blood thinners and blood pressure medications. Always consult a healthcare provider before use if you are on prescription drugs.

Yes, though rare, some individuals may experience allergic reactions to hemp seed oil. Symptoms can include skin irritation, rashes, or, in severe cases, difficulty breathing. People with known cannabis allergies should be cautious.

Some users report mild fatigue or drowsiness after taking hemp seed oil. For those sensitive to this effect, it may be helpful to take the oil in the evening rather than during the day to avoid interfering with alertness.

There is not enough reliable information to determine if hemp seed oil is safe for use during pregnancy or while breastfeeding. For safety, it is best to avoid it or consult a doctor.

No, hemp seed oil is not psychoactive. It is pressed from the seeds of the hemp plant and contains negligible amounts of THC, the compound responsible for a 'high.' It is distinct from CBD oil.

Yes, the omega fatty acids in hemp oil have been shown to help lower blood pressure. This could be a risk for individuals who already have low blood pressure or take medication to manage it, potentially causing dizziness.