Your Insider’s Guide to Supplement Safety

Kristy Horner, BSc. Pharm, is a pharmacist who works at the Robson location of Pure Integrative Pharmacy. She has a passion integrating natural and complementary health solutions to achieve the best health outcomes for her patients. Furthermore she specializes in compounding, which allows her to create customized medications for her people and animal clients. We love her integrative approach, and her ability to create customized treatments for her clients! For more information about her approach, please visit

Supplements and Safety: An Insider’s Guide

As a pharmacist working in an integrative practice I believe that supplements can be a powerful tool to boost one’s health and improve your well-being.  With the selection of supplements growing daily it can be difficult to choose the supplement that is right for you.  It is important to remember that just because a supplement is natural does not mean it is necessarily safe for everyone.  You need to consider your medical history, current medications and allergies when selecting the best supplement.


You want to verify that all the ingredients in the supplement you are contemplating will not exacerbate any known allergies or intolerances.  Herbs and vitamins can have multiple active ingredients that will you need to consider.  A known allergy to one member of a plant family can increase you risk of reacting to another member in the same class.  Ragweed which may cause allergic symptoms for some people is in the same family as Echinacea.  You will want to evaluate the source and form of the supplement as well.  Glucosamine may be derived from the exoskeletons of crabs and lobsters which could cause an allergic reaction in those with a shellfish allergy.

Another important consideration is the non-medicinal ingredients in your supplements.  The fillers and binders used to make capsules and tablets can exacerbate an allergy or intolerance.  Some supplements may contain lactose, soy, gluten, wheat, nuts, eggs, corn, and/or dairy.  If you have a condition like celiac disease be aware to check the ingredients listed on the label.  Gelatin capsules come from pork or beef sources and should be avoided by patients who are vegan or cannot consume animal products.  Herbal tinctures may contain alcohol.


Natural medicines can have potential serious interactions with prescription drugs, over-the-counter medications, lab tests and other natural supplements.  Before starting a new supplement I recommend checking with your pharmacist or doctor to make sure there are no potential interactions. An interaction may either increase or decrease the effect of your medication.  Furthermore, an interaction can increase your risk of side effects. Listed below are some examples of interactions between supplements and medications.




Anti-coagulant drugs (warfarin, clopidogrel, dalteparin)

Garlic, fish oils, ginseng, turmeric, ginkgo

Increased risk of bleeding

Antidepressants (sertraline, amitripline, venlafaxine) and DM (cough suppressant)

St. John’s Wort, 5-HTP, SAMe, tryptophan

Serotonin syndrome (too much serotonin)

Antibiotics (ciprofloxacin, tetracyclines)

Iron, Calcium

Decreased antibiotic absorption


Chromium, ginseng

Risk of low blood sugar (hypoglycemia)


Alpha-Lipoic acid, CoQ10, Vitamin E

May reduce effect of chemotherapy


If you are going for a medical lab test you should check to make sure that any supplements you take will not influence your results.  For example liver function tests may be influenced by taking black cohosh or N-acetyl cysteine.  Also, INR levels will be affected by fish oils, green tea or dandelion.

Medical History

Your medical history may also influence which supplements are safe to take.  Most supplements should be avoided in women who are pregnant or breast-feeding due to lack of safety evidence.  The same applies to the use of many herbal supplements for children.  You should ask your doctor if you need to discontinue any natural medicine prior to surgery as they may influence your recovery.  For example, fish oils are known to increase bleeding and should be discontinued one week prior to surgery. Fish oils are also contraindicated in patients with blood clotting disorders. Natural products can influence chronic medical conditions like diabetes, hyperthyroidism, high blood pressure or epilepsy.  Licorice is known to increase blood pressure for some patients.  Diabetics taking supplements that may lower their blood sugar like alpha-lipoic acid or cinnamon may need their medication doses adjusted if their blood sugars become too low. Those with a history of hormone-sensitive breast cancer should avoid supplements with estrogen-like activity such as soy and evening primrose oils.

I believe supplements can be used safely to complement your health.  Just make sure to work with your doctor, pharmacist and other health care providers to achieve a safe integrative approach to optimize your health.