The decision to stop taking supplements before surgery is a mandatory safety measure. Supplements, including herbal remedies, vitamins, and minerals, are non-prescription products containing biologically active compounds. While often viewed as natural, these agents can pose risks during the perioperative period—the time before, during, and immediately after surgery. Full transparency with the surgical team about all ingested products is paramount to prevent adverse outcomes, as many patients do not disclose this usage.
How Supplements Increase Bleeding Risk
Many supplements disrupt the body’s clotting cascade, increasing the risk of excessive blood loss during surgery. This heightened bleeding risk can lead to complications like hematoma or the need for a blood transfusion, which prolongs recovery. The mechanism often involves antiplatelet activity, where the supplement interferes with the function of platelets, the small blood cells that form a primary clot.
Garlic and high-dose Vitamin E possess potent antiplatelet effects, inhibiting the aggregation necessary for clot formation. Garlic directly interferes with platelet function, similar to some anticoagulant medications. High-dose Vitamin E (over 400 international units per day) also inhibits platelet activation. Other herbal products, such as ginkgo biloba, can also reduce the blood’s ability to clot effectively, leading to uncontrolled bleeding.
The risk is compounded when supplements interact with other medications the patient may be taking. Dong Quai, a traditional Chinese herb, contains substances that can potentiate the effects of prescription blood thinners. The cumulative effect of platelet inhibition dramatically increases the likelihood of excessive bleeding. Allowing the body’s natural clotting function to return to its baseline state is critical for a safe operation.
Interference with Anesthesia and Vital Signs
Supplements can interact unpredictably with anesthetic agents, destabilizing vital signs and complicating the anesthesia process. A major concern involves the Cytochrome P450 (CYP450) enzyme system, which is responsible for metabolizing most drugs, including many anesthetics. Some herbal supplements can either speed up (induce) or slow down (inhibit) the activity of these liver enzymes.
St. John’s Wort is a potent inducer, causing the body to break down anesthetic drugs faster than expected. This rapid metabolism can reduce the anesthetic’s effect, potentially causing the patient to wake up prematurely during the procedure. Conversely, supplements like Echinacea can inhibit the enzymes, slowing the breakdown of anesthetics and resulting in prolonged sedation. Delayed emergence from anesthesia may require extended monitoring and increase the risk of respiratory complications.
Other supplements can directly affect cardiovascular stability. Ephedra, also known as Ma Huang, acts as a stimulant and can lead to dangerous hypertension and rapid heart rates during surgery. Ginseng has been associated with heart rate irregularities and blood pressure fluctuations, while garlic may cause low blood pressure (hypotension). These erratic vital signs make it harder for the anesthesiologist to maintain the controlled state necessary for patient safety.
Common Supplements Requiring Cessation
A wide range of common supplements must be discontinued before surgery due to their active components and associated risks. Supplements known primarily for increasing bleeding risk interfere with platelet aggregation or possess blood-thinning properties. These include:
- Garlic
- Ginger
- Ginkgo biloba
- High-dose Vitamin E
- Fish oil (especially doses exceeding three grams per day)
- Feverfew and turmeric
Supplements that pose a risk of interacting with anesthesia or causing excessive sedation must also be stopped. Kava and Valerian root, often used for anxiety and sleep, can intensify the sedative effects of general anesthesia, potentially leading to respiratory depression. St. John’s Wort is specifically problematic due to its powerful effects on liver enzyme activity, which alters the metabolism of anesthetic agents.
Metabolic and cardiovascular risks are associated with other popular supplements. Ginseng is a concern because it can affect both blood pressure and blood sugar levels, increasing the risk of hypoglycemia during fasting. Ephedra, or Ma Huang, is a potent stimulant that can lead to severe cardiovascular instability, including arrhythmias.
Establishing a Mandatory Stop Timeline
The standard recommendation for most high-risk supplements is to discontinue use at least 7 to 14 days prior to the scheduled surgery date. This two-week window allows sufficient time for the body to metabolize and excrete the supplement’s components, normalizing clotting function and liver enzyme activity. Patients must disclose all supplements, including herbal teas and protein powders, to their surgeon and anesthesiologist. The final, personalized stop date is determined by the specific supplement, its dosage, the type of surgery, and the patient’s individual health status.