What are the Side Effects of Dried Goji Berries?

January 14, 2026 •

4 min read

Over 2,000 years of use in traditional Chinese medicine has established goji berries as a popular superfood. However, as with many foods, consuming dried goji berries can lead to side effects for certain individuals, including potential drug interactions and allergic responses.

Quick Summary

Goji berries are generally safe in moderation, but can cause digestive upset, especially when first introduced. They are known to interact with blood thinners and diabetes medications, and should be used with caution during pregnancy. Some individuals may experience allergic reactions.

Key Points

Drug Interactions: Goji berries can interact dangerously with anticoagulants like warfarin, diabetes medications, and blood pressure drugs.
Digestive Upset: Overconsumption can lead to bloating, gas, and diarrhea due to high fiber content, especially in those new to the berries.
Allergic Reactions: Individuals with nightshade sensitivities may experience allergies, with symptoms ranging from skin rashes to rare anaphylaxis.
Pregnancy Concerns: Due to a compound called betaine, excessive intake may stimulate uterine contractions, so pregnant and breastfeeding women should be cautious.
Quality and Contamination: The sourcing and quality of goji berries are important, as some products may contain pesticides or heavy metals.
Insomnia: Their energizing properties can interfere with sleep if consumed late in the day or in excessive amounts.
Moderation is Key: For most healthy adults, dried goji berries are safe when consumed in moderation, such as the recommended 30g daily.

Common Side Effects from Overconsumption

Dried goji berries, while nutritious, can cause minor gastrointestinal problems if consumed in large amounts, primarily due to their high fiber content. Individuals may experience symptoms such as stomach cramps, bloating, gas, and diarrhea as their digestive system adjusts to the increased fiber intake. Gradually increasing your intake is recommended to avoid these issues.

Digestive Issues

Bloating and Gas: The fiber in goji berries can lead to increased gas production and bloating, particularly for those with sensitive digestive systems.
Diarrhea: Ingesting too many berries at once can overstimulate the digestive tract, potentially causing loose stools or diarrhea.

Sleeplessness and Insomnia

Goji berries have energizing properties that, while beneficial for some, can interfere with sleep patterns for others. Consuming them later in the day, especially in excess, can lead to restlessness or insomnia.

Serious Interactions with Medications

One of the most significant concerns regarding goji berries is their potential interaction with certain prescription medications. These interactions can be severe, altering the effectiveness of the drugs and posing a health risk.

Blood Thinners (Anticoagulants)

Warfarin (Coumadin): Goji berries can increase the effects of warfarin, a blood-thinning medication, significantly raising the risk of bleeding and bruising. Healthcare providers advise patients on warfarin to avoid goji berries entirely.
Regular Monitoring: For anyone taking anticoagulants, it is critical to have blood clotting levels monitored regularly if goji berries are consumed, and always under a doctor's supervision.

Diabetes Medications

Hypoglycemia: Goji berries have been shown to lower blood sugar levels. When combined with diabetes medications like glipizide or insulin, this can cause blood sugar to drop dangerously low, leading to hypoglycemia.
Close Supervision: Patients with diabetes must monitor their blood sugar closely and consult a healthcare provider before incorporating goji berries into their diet.

High Blood Pressure Medications

Hypotension: Goji berries can also have a blood pressure-lowering effect. For those already taking antihypertensive drugs, consuming goji berries could cause an excessive drop in blood pressure.

Liver-Metabolized Drugs

CYP2C9 Substrates: Goji berries can interfere with the liver's cytochrome P450 2C9 (CYP2C9) enzyme, which is responsible for breaking down certain medications. This can increase the concentration of these drugs in the bloodstream, heightening their effects and potential side effects.

Allergic Reactions

While uncommon, allergic reactions to goji berries can occur. As a member of the nightshade (Solanaceae) family, they may trigger reactions in individuals sensitive to other nightshade plants like tomatoes, potatoes, or tobacco. Symptoms can range from mild to severe.

Mild Symptoms: These may include skin rashes, itching, hives, and gastrointestinal upset.
Severe Symptoms: In rare cases, a more serious reaction known as anaphylaxis can occur, which requires immediate medical attention.

Pregnancy and Breastfeeding Concerns

There is controversy regarding the safety of goji berries during pregnancy. Some studies suggest they contain a compound called betaine which, in large amounts, may stimulate uterine contractions and potentially increase the risk of miscarriage. Due to the lack of sufficient research on human pregnancy, many medical sources advise pregnant and breastfeeding women to avoid goji berries.

Goji Berries vs. Common Dried Fruits: A Comparison


Feature	Dried Goji Berries	Raisins (Dried Grapes)	Dried Cranberries
Drug Interactions	Significant risk with blood thinners, diabetes, and blood pressure medications.	Minimal interaction risk; safe for most people.	Generally safe; no known major interactions.
Allergy Risk	Low, but possible, especially for those with nightshade sensitivities.	Low; generally safe unless allergic to grapes.	Low; generally safe unless allergic to cranberries.
Digestive Upset	Possible with overconsumption due to high fiber.	Can cause bloating or gas with overconsumption.	Can cause stomach upset in large quantities.
Glycemic Index	Lower than many dried fruits, but can still affect blood sugar.	High; can cause blood sugar spikes.	Variable; some sweetened versions are high in sugar.
Safety in Pregnancy	Controversial; generally advised to avoid or limit significantly.	Generally considered safe in moderation.	Generally considered safe in moderation.

Quality and Contamination Risks

The quality and source of goji berries are important considerations. Some products may be contaminated with pesticides or heavy metals if not grown and processed correctly. It is best to choose organic or certified berries from reputable suppliers to minimize this risk.

Conclusion: Navigating the Side Effects

While dried goji berries are celebrated for their nutritional benefits, understanding their potential side effects is crucial for safe consumption. For most healthy individuals, moderate intake poses little risk beyond mild digestive issues. The most serious concerns involve drug interactions, particularly with blood thinners and medications for diabetes or blood pressure. Individuals who are pregnant, breastfeeding, or have known nightshade allergies should exercise extreme caution or avoid them altogether. As with any dietary supplement, consulting a healthcare professional is the most prudent step to ensure goji berries are a safe addition to your diet.

Final Thoughts on Moderation

Ultimately, enjoying goji berries is about balance and awareness. They can be a healthy part of a well-rounded diet, but it is important not to view them as a miracle cure. Listen to your body, adhere to recommended serving sizes (typically around 2 tablespoons or 30g per day), and be vigilant about potential contraindications based on your personal health profile.

For more information on specific drug interactions, consider visiting reputable medical databases or consulting your physician.

Outbound Link

WebMD - Goji Berry Overview

Frequently Asked Questions

Individuals taking blood thinners (like warfarin), diabetes medication, or blood pressure medication should avoid goji berries. Pregnant and breastfeeding women, and those with a known allergy to nightshade vegetables, should also be cautious or avoid them entirely.

Yes, consuming large quantities of dried goji berries, particularly if you are not used to a high-fiber diet, can cause mild digestive issues such as bloating, gas, and diarrhea.

Goji berries can increase the effect of warfarin, a blood thinner, and raise the risk of bruising and bleeding. It is strongly recommended to avoid goji berries if you are on this medication.

Yes, there is some concern that a compound in goji berries, betaine, may cause uterine contractions. Due to limited research on humans, most medical sources advise pregnant and breastfeeding women to avoid them or use extreme caution.

Yes, allergic reactions can occur, especially in people with sensitivities to other nightshade vegetables like tomatoes or potatoes. Symptoms can include skin rashes and gastrointestinal issues.

A commonly suggested safe daily serving is around 30 grams, or approximately two tablespoons. However, it's always best to start with a smaller amount and monitor your body's reaction.

Some goji berries can be contaminated with pesticides or heavy metals. To mitigate this risk, it is important to purchase organic or certified products from reputable sources.