Patient guide · SPAQI 2021

Supplements before surgery: what to stop and when.

These stop times aren't GlowWell's opinion. They come from SPAQI, a medical society focused on getting patients ready for surgery. In 2021, its doctors reviewed 83 supplements and said which ones to stop, and when.

This list covers the 74 the panel said to stop, sorted by timing.

Download the printable guide (PDF)

6
Stop completely
60
Stop 2 weeks before
2
Stop 48 hours before
6
Stop 24 hours before

How to use this list

Your surgical team's instructions come first. If they tell you something different, follow them.
This list covers supplements only. Never stop a prescription medicine because of it.
Check every ingredient in a blend. If a product contains anything on a stop list, treat the whole product as on that list.
Bring the bottles, or photos of the labels, to your pre-op visit.

Search a supplement

Stop completely

Not recommended at all, with or without surgery

Stop these as early as you can, and tell your team what you were using.

CBDCannabidiol oils, gummies, hemp extracts: May affect how blood clots. Can interact with anesthesia medicines.
DMAADimethylamylamine; some pre-workout and weight-loss products: Acts like a strong stimulant on the heart and blood pressure.
EphedraMa huang: Can cause dangerous heart rhythms. Banned in U.S. supplements.
Garcinia cambogiaHCA; weight-loss products: Linked to serious liver injury.
Kratom: Acts like an opioid and a stimulant. If you use it daily, don't quit all at once — ask your team how to taper.
MarijuanaCannabis, THC; smoked, vaped, or eaten: Can affect clotting, your heart, your airway, and how much anesthesia you need. Avoid at least 3 days before; 2 weeks is better.

Stop 2 weeks before

Last dose 14 days before your surgery date

For many of these, no one knows how long they stay in the body, so 2 weeks is the safe default. Coffee and tea as drinks are fine.

Agaricus mushroomAgaricus blazei: May lower blood sugar
Aloe (by mouth)Aloe vera juice or capsules: May lower blood sugar. May raise bleeding risk.
Alpha-lipoic acidALA, lipoic acid: May lower blood sugar
American ginsengPanax quinquefolius: May lower blood sugar. May affect clotting.
AndrographisKing of bitters: May lower blood pressure. May affect clotting.
ArnicaArnica montana tablets or pellets: May raise bleeding risk. Follow your surgeon's plan.
BanabaBanaba leaf, corosolic acid: May lower blood sugar
Bitter melonKarela, Momordica: May lower blood sugar
Bitter orangeSynephrine; weight-loss products: May raise blood pressure
Black tea extractCapsules or concentrates, not brewed tea: May raise bleeding risk. Contains caffeine.
BoldoBoldo leaf: May raise bleeding risk. Can be hard on the liver.
BromelainEnzyme from pineapple stem and core: May raise bleeding risk
Caffeine supplementsCaffeine pills; energy and pre-workout powders: Raises heart rate and blood pressure. Cut back slowly.
Casein peptidesMilk-protein peptides sold for blood pressure: May lower blood pressure
Cassia cinnamonCinnamon capsules or extract: May lower blood sugar
Cat's clawUña de gato: May raise bleeding risk
ChromiumChromium picolinate: May lower blood sugar, especially with insulin
Coenzyme Q10CoQ10, ubiquinone, ubiquinol: May lower blood pressure
DanshenRed sage, Salvia miltiorrhiza: May raise bleeding risk. May lower blood pressure.
Devil's clawHarpagophytum: May raise bleeding risk
Dong quaiAngelica sinensis: May raise bleeding risk
Echinacea: Interacts with many medicines. A concern if you need immune-suppressing medicine.
EvodiaWu zhu yu: May raise bleeding risk
Fenugreek: May lower blood sugar. May raise bleeding risk.
Feverfew: May raise bleeding risk. Interacts with many medicines.
GarlicGarlic pills, garlic oil, aged garlic extract: May raise bleeding risk
GingerGinger capsules or extract: May raise bleeding risk
GinkgoGinkgo biloba: May raise bleeding risk
GlucomannanKonjac fiber: Slows how your body absorbs sugar
Goldenseal: Interacts with many medicines
Grapefruit extractGrapefruit pills or concentrates: Interacts with many medicines
GuaranaEnergy drinks and weight-loss products: May raise bleeding risk. Contains caffeine.
GymnemaGymnema sylvestre, gurmar: May lower blood sugar
Horny goat weedEpimedium: May lower blood pressure
Horse chestnutAescin; leg-vein products: May raise bleeding risk
Hu zhangJapanese knotweed: Has many active compounds, including resveratrol
Indole-3-carbinolI3C: Not enough safety information in people
IpriflavoneBone-health products: One report of a serious gut problem
KavaKava kava: May add to the drowsy effects of anesthesia and pain medicine
Kola nutCola nut: Contains caffeine. At the least, cut back slowly.
Lemon balmMelissa: May add to the drowsy effects of anesthesia
Licorice rootReal licorice, glycyrrhizin: Can lower potassium and make your body hold fluid
NettleStinging nettle: May lower blood pressure. Acts like a water pill.
Panax ginsengAsian, Korean, or red ginseng: May lower blood sugar. May raise bleeding risk.
PolicosanolSugar cane or rice bran wax extract: May raise bleeding risk
Prickly pear cactusNopal, Opuntia: May lower blood sugar
PycnogenolFrench maritime pine bark extract: May lower blood pressure
Quercetin: Interacts with some medicines
Red clover: May raise bleeding risk
Resveratrol: May raise bleeding risk
Saw palmetto: May raise bleeding risk
SchisandraFive-flavor berry, wu wei zi: Interacts with many medicines. On anti-rejection medicine? Ask before you stop.
Siberian ginsengEleuthero: May raise bleeding risk
SkullcapScutellaria: May add to the drowsy effects of anesthesia
St. John's wortHypericum: Changes how your body handles many medicines. Ask your team before you stop.
TurmericCurcumin: May raise bleeding risk
VanadiumVanadyl sulfate: May raise bleeding risk. May lower blood sugar.
Vitamin ETocopherol; also in many multivitamins: May raise bleeding risk
Yerba mate: Contains caffeine. Cut back slowly.
YohimbeYohimbine: Can push blood pressure up or down

Stop 48 hours before

Last dose 2 days before surgery

These leave the body faster, so 2 days is enough.

ChondroitinJoint-health products: May affect clotting. Can add to the effect of warfarin.
GlucosamineJoint-health products: May affect clotting. Can add to the effect of warfarin.

Stop 24 hours before

Last dose no later than the day before surgery

These need only a short stop — at least 24 hours ahead.

5-HTP5-hydroxytryptophan: Raises serotonin. Can react with some medicines used around surgery.
L-arginine*Arginine; some pre-workout and nutrition drinks: May lower blood pressure during surgery
L-tryptophanTryptophan: Raises serotonin. May add to drowsiness.
N-acetylcysteineNAC: May lower blood pressure during surgery
SAM-eS-adenosylmethionine: Raises serotonin
TheanineL-theanine: May lower blood pressure. May add to drowsiness.

*L-arginine is the only ingredient in PREP™ on this list. That's why PREP™ stops 24 hours before surgery. See every PREP™ ingredient →

Often stopped, but not by this panel: fish oil / omega-3, green tea extract, melatonin, passionflower, phenylalanine, German chamomile, hops, lavender, and valerian. The panel said these can usually be continued.

What about food?

Normal amounts in meals are fine. The panel reviewed supplements, not food, so this is general guidance.

Garlic, ginger, turmeric, cinnamon: Fine in meals; The concern is pills, extracts, and oils.
Fish: Fine in meals; Fish as a meal is fine.
Pineapple: Fine to eat; The concern is the concentrated enzyme sold in capsules.
Coffee and tea: Fine in your usual amounts; Follow your team's rules about when to stop eating and drinking.
Ginger, turmeric shots, garlic oil: Stop 2 weeks before; Treat these like supplements.

If you forgot to stop

Tell your surgical team right away: what you took, how much, and when.
Don't cancel your surgery on your own, and don't hide it.
For many procedures, your team can go ahead and watch you more closely.

Starting again after surgery

Ask your surgical team before you restart anything. Supplements that affect bleeding should wait until your team says the bleeding risk is low.

Where this list comes from

Cummings KC III, Keshock M, Ganesh R, et al. Preoperative Management of Surgical Patients Using Dietary Supplements: SPAQI Consensus Statement. Mayo Clinic Proceedings. 2021;96(5):1342-1355. doi ↗

This list is general education, not medical advice, and does not replace instructions from your surgical team. SPAQI and Mayo Clinic Proceedings have not reviewed or endorsed this list.

Download the printable guide (PDF) →

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