Clients take these and often do not mention them. These are the ones that actually change how their medications work.
Most clients do not consider herbs to be medicine, so they will not list them unless you ask directly.
Ask: "Do you take any vitamins, herbs, teas or anything from the health food store?"
Supplements are not FDA-regulated for potency or purity — the dose in the bottle may not match the label.
All four increase bleeding risk — stop them before surgery. The catch: ginseng decreases warfarin's effect while the other three increase bleeding. That reversal is a favorite exam question.
| Supplement | Stop before | Why |
|---|---|---|
| Ginkgo | 1–2 weeks | Bleeding |
| Garlic | 7–10 days | Bleeding, low glucose |
| Ginseng | 7 days | Bleeding, hypoglycemia, BP swings |
| Ginger | ~1 week | Bleeding |
| St. John's Wort | 5+ days | Alters anesthetic metabolism |
| Valerian | ~1 week | Adds to anesthesia; taper it |
| Kava | 24 hours | Adds to sedation, liver risk |
| Vitamin E, fish oil | 1–2 weeks | Bleeding |
• Mild to moderate depression
• Photosensitivity
• GI upset, dry mouth, dizziness
• Insomnia, restlessness
• The biggest interaction offender in all of herbal medicine. It is a strong CYP450 inducer, so it speeds up the breakdown of many drugs and makes them stop working.
• Reduces: oral contraceptives (breakthrough pregnancy), warfarin, cyclosporine, digoxin, HIV protease inhibitors, anticonvulsants, statins
• Serotonin syndrome when combined with SSRIs, SNRIs, triptans, tramadol, MAOIs
• Ask about it in every medication reconciliation
• Never stop or start it without telling the prescriber
• Stop at least 5 days before surgery
• Memory and cognition
• Peripheral vascular disease, intermittent claudication
• Tinnitus, vertigo
• Bleeding
• Headache, dizziness, GI upset
• Allergic skin reaction
• Seizures at high doses
• Increases bleeding risk with warfarin, aspirin, clopidogrel, heparin and NSAIDs
• Lowers the seizure threshold — caution with anticonvulsants
• May raise blood pressure with thiazide diuretics
• One of the 'G' herbs that make you bleed
• Stop 1-2 weeks before surgery
• Avoid in seizure disorders and in pregnancy
• Hyperlipidemia
• Hypertension
• General cardiovascular support
• Bleeding
• Body and breath odor
• GI upset, heartburn
• Allergic reaction
• Increases bleeding with anticoagulants and antiplatelets
• May lower blood glucose — watch with insulin and oral antidiabetics
• Reduces saquinavir levels
• A 'G' herb — bleeding risk
• Stop 7-10 days before surgery
• Watch for hypoglycemia in diabetics
• Nausea and vomiting, including pregnancy and motion sickness
• Osteoarthritis pain
• Dyspepsia
• Heartburn, GI upset
• Bleeding at high doses
• Mouth irritation
• Bleeding risk with anticoagulants and antiplatelets
• May lower blood glucose
• May potentiate antihypertensives
• A 'G' herb — bleeding risk
• Stop about 1 week before surgery
• Generally considered one of the safer supplements at culinary doses
• Fatigue and energy
• Stress and immune support
• Type 2 diabetes adjunct
• Insomnia, nervousness
• Hypertension, tachycardia
• Headache
• Mastalgia, vaginal bleeding
• Decreases the effect of warfarin — the exception among the G herbs, which usually increase bleeding
• Additive stimulation with caffeine and stimulants
• Hypoglycemia with insulin and antidiabetics
• Hypertensive crisis with MAOIs
• A 'G' herb, but it works the opposite way on warfarin — a favorite test point
• Stop 7 days before surgery
• Avoid in uncontrolled hypertension
• Prevention and treatment of colds and upper respiratory infection
• GI upset
• Rash and allergic reactions
• Hepatotoxicity with long use
• Reduces the effect of immunosuppressants — cyclosporine, corticosteroids, tacrolimus
• May add to hepatotoxicity with methotrexate, amiodarone, ketoconazole
• Avoid in autoimmune disease, HIV, tuberculosis and transplant clients — it stimulates the immune system
• Do not use longer than about 8 weeks
• Cross-allergy with ragweed, daisies and chrysanthemums
• Anxiety
• Insomnia
• Muscle relaxation
• Severe hepatotoxicity, including liver failure
• Sedation, drowsiness
• Scaly rash with long use
• Extrapyramidal symptoms
• Additive sedation with benzodiazepines, opioids, alcohol, barbiturates
• Compounds hepatotoxicity with acetaminophen, statins, methotrexate
• May worsen Parkinson symptoms with levodopa
• Banned in several countries for liver failure. Monitor LFTs.
• Never combine with alcohol
• Do not drive after taking it
• Stop 24 hours before surgery
• Insomnia
• Anxiety and restlessness
• Morning grogginess
• Headache, dizziness
• Rare hepatotoxicity
• Withdrawal symptoms if stopped abruptly after long use
• Additive CNS depression with benzodiazepines, barbiturates, opioids, alcohol, anesthesia
• May increase the effect of other sedatives
• Taper rather than stopping suddenly
• Tell anesthesia before surgery — it interacts with anesthetics; stop about 1 week before
• No driving after a dose
• Migraine prophylaxis
• Arthritis, fever
• Bleeding
• Mouth ulcers with chewed leaves
• GI upset
• Rebound headache on abrupt discontinuation
• Bleeding risk with anticoagulants, antiplatelets and NSAIDs
• NSAIDs may also reduce its effectiveness
• Taper, do not stop abruptly — rebound headaches
• Stop 1-2 weeks before surgery
• Avoid in pregnancy — it can stimulate contractions
• Benign prostatic hyperplasia symptoms
• GI upset
• Headache
• Decreased libido
• Mild bleeding risk
• Additive effect with finasteride and alpha blockers
• May interfere with hormone therapy and oral contraceptives
• Mild bleeding risk with anticoagulants
• Can lower PSA and mask prostate cancer — tell the provider before PSA testing
• Does not shrink the prostate; it treats symptoms
• Stop 2 weeks before surgery
• Menopausal hot flashes and night sweats
• PMS, dysmenorrhea
• Hepatotoxicity
• GI upset
• Headache, dizziness
• Rash
• Adds to hepatotoxicity with acetaminophen and statins
• May interfere with hormone therapy and tamoxifen
• May potentiate antihypertensives
• Monitor LFTs; stop for jaundice, dark urine or right upper quadrant pain
• Avoid in pregnancy, breastfeeding, and hormone-sensitive cancers
• Limit to about 6 months
• Liver support, hepatitis, cirrhosis adjunct
• Some mushroom poisoning protocols
• Mild GI upset and laxative effect
• Allergic reaction in ragweed-sensitive clients
• May affect CYP-metabolized drugs
• May lower blood glucose — watch with antidiabetics
• Generally well tolerated
• Still requires LFT monitoring if used for liver disease
• Not a substitute for treating the underlying cause
• Insomnia and jet lag
• Shift-work sleep disorder
• Delayed sleep phase
• Morning drowsiness
• Headache, dizziness
• Vivid dreams
• Mild hypothermia
• Additive sedation with CNS depressants
• May increase bleeding with anticoagulants
• Fluvoxamine markedly raises melatonin levels
• Take 30-60 minutes before bedtime, in a dark room
• Lower doses often work better than higher ones
• No driving after taking it
• Inflammation and arthritis pain
• Dyspepsia
• GI upset
• Bleeding at high doses
• Gallbladder contraction
• Bleeding risk with anticoagulants and antiplatelets
• May lower blood glucose
• May reduce iron absorption
• Avoid in gallstones and bile duct obstruction
• Stop 2 weeks before surgery
• Poor oral absorption without pepper or fat
• Osteoarthritis pain, especially the knee
• GI upset
• Headache
• Rash
• May increase INR with warfarin
• May raise blood glucose — monitor in diabetics
• Shellfish allergy — many products are shellfish-derived
• Monitor glucose in diabetics and INR on warfarin
• Takes 4-8 weeks to show any effect