13 Medication & Supplement Combinations You Should Avoid

With aging and chronic health issues, it’s common for individuals to take prescribed meds and often combine them with certain supplements.

Despite the frequent presence of meds and supplements in our lives, especially among the elderly, some experts note that combining certain meds and supplements may have serious side effects. 

According to the NCCIH, a lot of people tend to mix supplements and prescribed OTC meds without any awareness of the possible interactions. 

According to Danielle Crumble Smith, RDN, and certified registered dietitian at Top Nutrition Coaching, combining some dietary supplements and meds can cause various harmful effects.

The most common ones are a reduction in the drug’s effectiveness, unexpected side effects, and a higher risk of drug toxicity. 

Knowing this, if you’re taking meds and supplements, make sure you learn about the potentially risky combos that you need to be aware of!

13 Medication & Supplement Combos to Avoid

  1. Vitamin B6 and levodopa

Levodopa is a medication for Parkinson’s and if taken along with vitamin B6, its effectiveness may reduce. 

But, some levodopa meds have carbidopa which may help counteract this interaction. Those who take levodopa or levodopa-carbidopa intestinal gel may experience a deficiency in vitamin B6. 

This can lead to depression, neuropathy, and other complications. Your healthcare provider may advise you on supplementation with this vitamin in case it’s necessary for you. 

  1. Vitamin K and meds for blood thinning

Vitamin K may counteract the effects of meds for blood thinning such as warfarin and may reduce their effectiveness. 

If you’re taking these meds, consult your provider before introducing vitamin K supplements or if you plan to increase your dietary intake of foods with this vitamin. 

  1. Thyroid hormone replacement meds and iron or calcium

Some supplements like calcium and iron may impede the absorption of thyroid hormone replacement meds like levothyroxine. 

This is why you should take the supplements and the meds at least four hours apart. 

  1. Antacids with aluminum and vitamin C

Vitamin C elevates the aluminum absorption from antacids that neutralize stomach acid and are used to alleviate indigestion and heartburn. 

But, taking vitamin C and antacids together may cause toxic aluminum levels in the body. 

This is why it’s highly recommendable to take them at least two hours apart. 

  1. Blood thinning and vitamin E

Vitamin E may elevate the bleeding risk when you take it with meds for blood thinning like warfarin. 

If you’re prescribed this medication, consult your healthcare provider before you introduce vitamin E supplements. 

  1. Various meds and St John’s Wort 

St John’s Wort supplements may interact with certain meds like birth control pills, antidepressants, and blood thinners. 

It may lower their effectiveness and this combo may cause harm.

  1. Blood clotting meds and goldenseal 

Supplements with goldenseal may interact with certain meds like the ones for blood clotting. 

They can lower the capacity of the body to clot blood, resulting in bruising and bleeding. 

Taking into account that this is a serious interaction, it’s generally recommended to avoid combining this supplement and blood clotting meds. 

  1. Blood pressure meds and diuretics and licorice root

Some supplements with licorice root may interact with meds for blood pressure and diuretics. 

They can worsen the side effects and in some cases even cause severe issues like potassium imbalance or fluctuations in blood pressure. 

  1. Blood-thinning meds and ginkgo biloba 

Ginkgo biloba supplements may elevate the chance of bleeding if taken along with blood-thinning meds like aspirin or warfarin.

  1. Diabetes meds and CoQ10

CoQ10 is recommendable for support of cardiovascular health; however, it can also decrease blood sugar levels. 

So, if you’re on diabetes meds, taking this supplement as well may further increase the chance of low blood sugar. 

If you’re considering this supplement, consult your healthcare provider first.

  1. Antibiotics and iron 

Some antibiotics, especially the ones from the tetracycline family may interact with iron supplements and thus, decrease their effectiveness. 

To maximize the absorption of antibiotics and iron, make sure you take them several hours apart. 

  1. Blood thinners and garlic supplements 

Garlic is known for its blood-thinning characteristics. Therefore, if taken with aspirin or warfarin, blood thinners, it may elevate the risk of bleeding. 

Always consult your healthcare provider about which medication and supplement combination are good for you and which ones to avoid. 

  1.  Melatonin and sedating herbs

It’s not difficult to overdo it with herbs or supplements that have sedative characteristics. 

When you take them together, you risk excessive sleepiness. Therefore, always make sure you know which herbs you can combine in case you’re taking melatonin and which ones you should avoid.