Serious Side Effects Of Grape Seed Extract: Risks, Interactions, and Precautions
Herbal supplements may seem harmless, but spotting their hidden risks keeps you safer.
Grape seed extract (GSE) is a popular supplement derived from the seeds of grapes, often touted for its antioxidant properties and potential health benefits. However, like many herbal supplements, it is important to understand its possible side effects, interactions, and risks.
What Is Grape Seed Extract?
Grape seed extract is produced from the seeds of Vitis vinifera grapes. Rich in oligomeric proanthocyanidin complexes (OPCs), it is often used for cardiovascular health, skin care, and anti-inflammatory purposes. Despite its widespread use, grape seed extract is not free from adverse effects, especially with prolonged or high-dose consumption.
Potential Side Effects of Grape Seed Extract
While many people tolerate grape seed extract well, research and clinical reports have identified a range of possible side effects that users should be aware of. Most are mild and resolve after discontinuation, but some can be serious or even life-threatening in rare circumstances.
1. Gastrointestinal Disturbances
- Nausea and Vomiting: One clinical case documented recurrent nausea and vomiting after grape seed extract use, which resolved upon cessation.
- Diarrhea: Diarrhea is among the most frequently reported symptoms associated with GSE, and it may manifest quickly after consumption.
- Abdominal Pain: Some users report cramping and abdominal pain, which may or may not be accompanied by other digestive symptoms.
2. Headaches and Dizziness
- Headache: Mild to moderate headaches are occasionally noted as an adverse effect.
- Dizziness and Weakness: Some users, as described in clinical reports, have experienced acute weakness and dizziness, which resolved after discontinuing the extract.
3. Sore Throat and Respiratory Reactions
- Sore Throat: Additional symptoms may include a sore throat or cough, possibly as part of an allergic reaction.
4. Muscle Pain
- Some individuals report muscle pain or cramps while taking grape seed extract.
5. Dry Mouth
- Dry mouth can occasionally occur as a side effect.
6. Allergic Reactions (Hypersensitivity)
Though rare, grape seed extract may provoke serious allergic reactions, especially in those with existing plant or herbal allergies. Reactions may include:
- Rash or hives
- Itching or swelling (particularly of the face, tongue, or throat)
- Severe dizziness
- Trouble breathing
An allergic reaction of this nature requires immediate medical attention.
7. Drug Interactions and Enhanced Bleeding Risk
Grape seed extract can interact with a number of medications, amplifying the risk of serious side effects:
- Blood Thinners: GSE may increase the risk of bleeding, especially in those taking blood-thinning medications like warfarin, clopidogrel, or aspirin.
- Cytochrome P450 Substrate Medications: GSE may affect drugs metabolized by liver enzymes, such as certain antidepressants, antipsychotics, and cardiovascular drugs.
- Lactobacillus Products: Grape seed extract may reduce the benefits of probiotic supplements.
What others are reading
8. Unknown Risks During Pregnancy and Breastfeeding
Little data exists on the safety of grape seed extract for pregnant and breastfeeding women. Its effects on fetal and infant development are not well understood, so most experts recommend avoiding GSE in these populations.
Who Should Avoid Grape Seed Extract?
Certain individuals should exercise additional caution or abstain from using grape seed extract altogether:
- People with allergies to grapes or related plants.
- Individuals on anticoagulant or antiplatelet drugs (including warfarin, clopidogrel, aspirin).
- Those with scheduled surgeries, as GSE may increase the risk of perioperative bleeding.
- Children and infants, due to insufficient safety data.
- Pregnant or breastfeeding women unless advised by a healthcare provider.
Drug Interactions: What Should You Avoid?
| Drug or Class | Potential Interaction/Effect |
|---|---|
| Warfarin, clopidogrel, aspirin (Blood thinners) | Increased risk of bleeding |
| Cytochrome P450 substrate drugs (certain antidepressants, antipsychotics, cardiovascular drugs) | Altered drug metabolism and unpredictable drug levels |
| Lactobacillus-containing probiotics | Reduced probiotic efficacy |
| Vitamin C | May raise blood pressure if combined with GSE in those with hypertension |
Precautions: When to Consult a Doctor
Before starting grape seed extract, consult your healthcare provider, especially if you:
- Have any chronic medical conditions (e.g., cardiovascular disease, diabetes, liver disorders).
- Are taking prescription or over-the-counter medications regularly.
- Have known allergies to plants or botanical supplements.
- Are pregnant, breastfeeding, a child, or an elderly individual.
Case Studies and Clinical Evidence
While adverse effects are rare and typically mild, case reports illustrate that serious symptoms can occur. In one clinical case, a 49-year-old male developed recurrent nausea, vomiting, diarrhea, and acute weakness after using grape seed extract. Extensive medical evaluation revealed no other cause; symptoms resolved immediately after discontinuation, and the patient remained symptom-free for five years.
This underscores both the potential for adverse events with GSE and the lack of extensive controlled trial data detailing its safety profile.
General Recommendations for Safe Use
- Use only the recommended dosages as stated by labeling or prescribed by medical professionals.
- Monitor for side effects during initial use and discontinue immediately if adverse reactions occur.
- Avoid combining GSE with blood thinners or other interacting medications unless under medical advice.
- Purchase from reputable brands that provide clear labeling and ingredient sourcing.
- Inform your healthcare provider about all supplements and medications you are using.
Frequently Asked Questions (FAQs)
Q: Is grape seed extract safe for long-term use?
A: There is a lack of detailed long-term safety data for grape seed extract. Case reports suggest that side effects resolve after discontinuation, but the absence of controlled trials means uncertainties remain about prolonged use.
Q: Can grape seed extract cause bleeding?
A: Yes, grape seed extract may amplify the effect of blood thinners, potentially increasing the risk of bleeding. Anyone on anticoagulant or antiplatelet medications should avoid GSE or consult a healthcare professional.
Q: What should I do if I experience side effects from grape seed extract?
A: Discontinue use immediately and consult a healthcare provider. For serious reactions (such as severe allergic response, difficulty breathing, or significant bleeding), seek emergency medical care.
Q: Are there any people who should never take grape seed extract?
A: Yes. Children, pregnant or breastfeeding women, those with grape allergies, and anyone taking medications that interact with GSE (especially blood thinners) should avoid use unless given express clearance by a healthcare provider.
Q: Can I take vitamin C with grape seed extract?
A: Caution is advised. Combining vitamin C and grape seed extract may raise blood pressure, especially if you already have hypertension.
Summary Table: Key Adverse Effects Of Grape Seed Extract
| Adverse Effect | Description | Severity |
|---|---|---|
| Nausea, vomiting, diarrhea | Digestive upset, may be severe in rare cases | Mild to moderate |
| Headache, dizziness | May present as mild discomfort or acute weakness | Mild |
| Allergic reactions | Rash, facial swelling, difficulty breathing | Severe (rare) |
| Increased bleeding | Especially when combined with blood thinners | Serious, potentially life-threatening |
Conclusion
Grape seed extract is a widely used supplement with potential health benefits, but it is not without risks. Adverse effects, though rare, can include gastrointestinal upset, headaches, allergic reactions, and increased risk of bleeding—especially in those taking interacting medications. Pregnant and breastfeeding women, children, and individuals on certain drugs should avoid GSE unless advised by a healthcare provider. Always consult a doctor before beginning any new supplement regimen, and monitor carefully for adverse reactions.
References
- https://digitalcommons.kansascity.edu/studentpub/428/
- https://www.webmd.com/drugs/2/drug-16759/grape-seed-extract-oral/details
- https://pubmed.ncbi.nlm.nih.gov/25688637/
- https://www.urmc.rochester.edu/encyclopedia/content?contenttypeid=19&contentid=grapeseedextract
- https://www.drugs.com/mtm/grape-seed.html
- https://www.medicalnewstoday.com/articles/263332
- https://www.ncbi.nlm.nih.gov/books/NBK590485/
- https://www.tandfonline.com/doi/full/10.3109/19390211.2015.1008617
Similar Articles
Read full bio of Sneha Tete
