What You Need to Know Before Mixing Supplements and Prescriptions

by Brad

drug and vitamin interactions

The use of supplements in America is at an all-time high. Currently more than 53% of the entire population use supplements on a daily basis. At the same time, we also know that the use of prescription medications is higher than ever before. Nearly half of the country takes prescribed medicine every days, while 90% of older Americans do so.

This has lead many researchers to study how the vitamins, minerals and other factors in the supplements interact with the drugs in the prescribed medications. Combining drug and supplement intake can often be beneficial, but taking certain drugs with certain supplements can also have terrible results.

Some supplements can increase the effectiveness of the drug, resulting in an amplified effect of the intended outcome. Other supplements can severely impede the prescription from having any desired effect. And at the same time, many prescriptions can prohibit the body’s ability to create and/or absorb certain nutrients, so supplementation may be crucial to long-term health.

The most common negative drug-supplement interactions occur when the supplement affects the blood levels of the drug. It can interfere with absorption and alter metabolism. A familiar example is the herb St. Johns wort which has effects ranging from reducing the effectiveness of birth control pills to actually becoming very toxic when taken with anti-depressants like Prozac (SSRI’s).

All this is complicated by the fact that no two humans, and their metabolic systems, are alike. Certainly the reactions will vary by individual, and be altered further by the number of medications and supplements taken.

If you’re taking medications, it is smart to discuss the supplements you’re taking with your doctor and to let him/her know before you start or stop any supplements. But you also need to do your own homework. Doctors simply aren’t taught much about nutrition, and certainly aren’t taught much about nutrient depletion from prescription use.

Here are some of the more commons drug-supplement interactions, both positive and negative. And where possible, we’ll share ideas on how to deal with the interactions.


The effectiveness of St. John’s wort on depression is still up for debate, but what is for sure is that it affects enzymes in the liver and intestines. This effect in turn significantly alters the blood levels of more than 30 different drugs. In the case of birth control pills, St. John’s wort speeds up the breakdown of the hormone and can reduce the effective dose up to 50%, meaning, “Surprise, we’re pregnant!”

Taking extra calcium can cause issues because it binds with other drugs, decreasing their absorption. In essence, the drug passes through the body with no effect. This is often seen with antibiotics, thyroid medications, and drugs used to treat Parkinson’s disease. Because so many older woman take calcium supplements, they need to take special consideration for this affect. Take calcium (as well as magnesium if taken in high doses, which can have the same affect) at least three hours apart from these types of drugs.

Popular for heart health, the anticoagulant properties of garlic, ginseng, and ginkgo can reduce the risk of cardiovascular disease in many forms. However, those same properties can pose a risk of heavy bleeding for people taking warfarin, a drug often used to treat certain forms of heart disease. If taking warfarin, always talk to your doctor before taking any of these herbs (or aspirin) at therapeutic doses.

Be Aware

Because drugs typically work by blocking a certain pathway within the body, they can often lead to nutrient deficiencies. Supplementing to replace those nutrients can not only increase the drug’s effectiveness, but can also reduce side effects.

Minerals like calcium, magnesium, potassium, and zinc can all be depleted by many medication prescribed for digestive issues as well as high blood pressure. Antacids, acid reflux drugs, and diuretics that decrease stomach acid should be taken as far apart as possible from mineral supplements in order to improve absorption levels.

Coenzyme Q10 (coQ10) is a natural antioxidant that increases energy and is beneficial for heart health. Birth control pills, diabetes drugs, diuretics, and statin drugs all reduce the level of coQ10 in the body. High doses of vitamin E can also reduce blood levels of coQ10 because it is used in the process of eliminating oxidized vitamin E. Because coQ10 isn’t found in food, supplementing may be necessary to return the blood levels to normal.

The importance of B vitamins in the body is hard to exaggerate. They’re crucial to longevity. Acid reflux drugs, birth control pills, and diabetes drugs can deplete B12, B6, folic acid, and other Bs, increasing the risk for heart disease and other issues. If you take any of these drugs, supplementing with a high-quality B complex product would be wise.

Good News

The effectiveness of some drugs may be enhanced by certain nutrients which may even allow you to decrease the dose of the medication over time.

SSRI antidepressants can be more effective when coupled with high-dose L-methylfolate, the natural form of folate. This form of folate is actually an FDA-approved treatment for depression. The studies used 5-15 grams of L-methylfolate daily, though 400 – 800 mcg may be beneficial as well.

Blood pressure and nitrate drugs can be enhanced by taking N-acetyl cysteine (NAC). NAC is an antioxidant and a precursor to glutathione which plays a major roll in cell detoxification and also stimulates healthy artery walls. NAC has been shown to improve the effectiveness of ACE inhibitors and can also counteract liver damage from sustained use of acetaminophen (depletes glutathione in the liver).

Adding to the list of its benefits in the human diet, fish oil has been shown to have the most positive drug interactions of all supplements studied. The omega 3 fats in fish oil stimulate the production of anti-inflammatory substances in tissues, and this in turn enhances the benefits of anti-inflammatory drugs, like arthritis drugs and NSAIDS. They’ve been shown to be beneficial and safe to take with statins and warfarin.

It’s no secret that fish oil can alleviate depression symptoms, both in mild and severe cases. The use of fish oil can reduce the antidepressant dosage needed, even in those who are bipolar. Other studies have shown the effectiveness of fish oil in treating arthritis and colitis.

In a perfect world, neither prescription medications nor supplements would be needed. A clean diet can eliminate the need for many types of prescription medications, but for many reasons there may be a need for continued use of them. And in reality, even with the best diet, our modern lifestyle and environment can make it very difficult to get all of the nutrients we need without a little help.

Knowing about natural solutions that can reduce the need for pharmaceutical drugs, and knowing how to use them wisely in combination with necessary medications, can enhance the overall quality of life.

For more information about drug-nutrient interactions, and to research specific examples, www.pilladvised.com is a helpful resource.

About the author...

 discovered the benefits of natural food when he watched a loved one go from poor health to full well-being after adapting a clean food diet. Such an event opened his eyes to the power of clean foods and fueled his motivation to help others eat the best way possible for their body.

{ 2 comments… read them below or add one }

Lea Taylor October 17, 2012

Thank you for this article! Now I know that I can still take my fish oil supplements.
I am eating a clean, healthy diet and I still need some arthritis medicine, so I agree when you say we don’t live in a perfect world and in some cases there is still a need for them.


Brad October 19, 2012

You’re welcome, Leah. Yeah, definitely keep up on the fish oil. That’s a good one for about everything!


Leave a Reply

Your email address will not be published. Required fields are marked *