Can I take Black garlic and Evening primrose oil together?
Drug interaction guide
Originally published 25 Jan 2026
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Taking black garlic and evening primrose oil together may increase your risk of bruising or bleeding. This is because both supplements can thin the blood and slow down the time it takes for a clot to form.
Why this happens
Black garlic contains compounds that prevent blood cells (platelets) from sticking together. Evening primrose oil contains gamma-linolenic acid (GLA), which also has mild blood-thinning effects. When used together, these effects can add up, making it harder for your blood to clot.
What you should do
Use this combination with caution. Watch for signs of unusual bleeding, such as nosebleeds, bleeding gums when brushing your teeth, or dark, tea-coloured urine. If you have an upcoming surgery or dental procedure, stop taking both supplements at least two weeks beforehand. If you are already taking prescribed blood thinners (like warfarin or aspirin), do not take these supplements without speaking to your doctor first.
Important precautions
Surgery or bleeding disorders
Both supplements can thin the blood and increase the risk of bleeding. You must stop taking them at least two weeks before any planned surgery or dental procedure.
Epilepsy or seizure disorders
Evening primrose oil may lower the seizure threshold, making fits more likely, especially if you are taking medication for epilepsy or schizophrenia (such as phenothiazines).
Food and drink warnings
Alcohol
While there is no direct chemical interaction, both black garlic and evening primrose oil can have mild blood-thinning effects. Excessive alcohol consumption can also thin the blood and increase the risk of stomach irritation; therefore, moderation is advised to avoid an increased risk of bruising or bleeding.
Using other medicines
Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.
Disclaimer
This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.
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