Medications · Supplements
Supplements Before Surgery
'Natural' doesn't mean 'harmless around surgery.' Several common supplements thin the blood or interact with anesthesia — so the single most useful thing you can do is tell your team everything you take, and stop the ones that matter in good time.
The short answer
Why 'natural' supplements matter around surgery
Supplements aren't tested or regulated like medicines, so their strength and purity vary, and several have real effects on the body that matter during an operation — mostly on bleeding and on how you respond to anesthesia. Because people often don't think to mention them, they're a common blind spot. Disclosing them is the fix.
Supplements usually stopped before surgery
| Supplement | Why it matters | Often stopped |
|---|---|---|
| Fish oil / omega-3 | Thins the blood (less platelet stickiness) | ~1–2 weeks before |
| Vitamin E (high dose) | Thins the blood | ~1–2 weeks before |
| Garlic, ginger, ginkgo, ginseng (the "4 G's") | Thin the blood | ~1–2 weeks before |
| Turmeric / curcumin (high dose) | Thins the blood | ~1–2 weeks before |
| St John's Wort | Interacts with anesthetic & other drugs | ~1–2 weeks before |
| Vitamin E / fish oil in a normal multivitamin | Low dose — usually fine | Tell your team |
Spices used in cooking (a curry with turmeric, garlic in food) aren't the concern — it's concentrated supplement doses.
Dedicated guides
- Fish oil (omega-3) before surgery
- Vitamin E before surgery
- Turmeric / curcumin before surgery
- Herbal supplements (garlic, ginkgo, ginseng, St John's Wort)
- Melatonin before surgery
- CBD before surgery
Bring a full list to your pre-op visit
Frequently asked questions
Which supplements should I stop before surgery?
The main ones that thin the blood — fish oil (omega-3), vitamin E, garlic, ginkgo, ginseng, ginger and high-dose turmeric — are usually stopped about 1–2 weeks before. St John's Wort is stopped because it interacts with anesthetic drugs. When in doubt, tell your team and ask about each one.
How long before surgery should I stop supplements?
A common, cautious rule is to stop blood-thinning and herbal supplements about 1–2 weeks before surgery, which gives their effects time to wear off. Your team may give different timing, so confirm — and always disclose everything you take, including 'natural' products.
Do I need to tell my team about vitamins and herbal products?
Yes — and they often won't think to ask specifically. Many people don't mention supplements because they assume natural means safe, but several affect bleeding or anesthesia. Bring a written list of everything: vitamins, minerals, herbal products and 'wellness' supplements, with doses.
Are normal multivitamins a problem before surgery?
A standard daily multivitamin is usually fine, but high-dose single supplements (especially vitamin E and fish oil) are the concern. Mention your multivitamin anyway so your team can check the doses — and stop standalone high-dose products as advised.