The Dangers of Cholesterol Supplements

Supplements for reducing high cholesterol don’t work very well. Even worse, they could be dangerous and can have unwanted side effects.

Many of us would like to lower low-density lipoprotein (LDL “bad”) cholesterol “naturally.” It may sound like a good idea to use a dietary supplement instead of a pharmaceutical drug. But natural remedies are not tested for safety or effectiveness. A supplement should never replace the medication prescribed by your doctor. “Natural” products often aren’t better, nor are they always safe.

Red yeast rice

Many people with high cholesterol take red yeast supplements as a “natural” alternative to statins, a drug that lowers cholesterol. The active compound (monacolin K) in red yeast rice lowers production of cholesterol in the liver. This statin is marketed as a pharmaceutical in purified form as lovastatin (Mevacor and generics).

Red yeast rice has been used for centuries in China as a heart remedy. But that doesn’t mean it is reliable or safe. The active ingredient in red yeast rice supplements can vary widely—from 0.2 to 14 milligrams1. That is well below the 20 or 40 milligrams in prescription lovastatin pills. In one study, one-third of the products contained cirtinin, a potential kidney toxin.

Reasons why red yeast rice supplements might be a bad move for you:

  • The low dosage probably won’t control your cholesterol.
  • The lack of regulation means they could be dangerous.
  • If you already take a statin, they could increase the risk of side effects, such as liver toxicity.
  • Because the product is not regulated, you have no idea of the purity or the amount of lovastatin in the product.

If you need a statin, stick with a prescription. You know exactly what you are getting in a prescription and the benefits are well documented. If you are worried about the costs, prescription lovastatin is often cheaper than red yeast rice and is covered by insurance.


Garlic has long been touted for its medicinal properties. Ancient peoples from Greece, Rome, Egypt, and China used garlic to treat dozens of ailments. It is also a key part of the heart-healthy Mediterranean diet.

Garlic contains potentially healthy compounds. Lab studies suggest that garlic (or its compounds) may help lower cholesterol. But effects seen in the lab have not been consistent or significant.

Garlic supplements manufacturers often make the heath claim that garlic pills lower cholesterol. But the evidence says that’s not necessarily the case. When researchers tested raw garlic and two popular garlic supplements for six months in people with high LDL cholesterol, they found no benefit.

Garlic supplements may also interact with some medications for:

  • Diabetes
  • HIV
  • Hypertension (high blood pressure)
  • Cancer
  • High cholesterol

Like raw garlic, supplements may cause:

  • Gastrointestinal discomfort
  • Bad breath
  • Body odor

Avoid garlic supplements. It is uncertain whether they even help lower cholesterol. And if it does, the effect is small. Supplements cannot replace medication. That said, there is no harm in eating more garlic in your food if you like it.


There was promising early research suggesting that this antioxidant mineral may lower cholesterol and help prevent heart disease. Lately, research has not been so kind to selenium.

One report2 found no connection between selenium supplements and a reduced risk for heart disease. Researchers also could not rule out the risk of developing type 2 diabetes when taking selenium supplements. They concluded that selenium supplements are neither helpful nor harmful in terms of heart disease. The supplement is unnecessary for people who eat healthy.

It’s best to steer clear of selenium supplements. High selenium is linked to an increased risk for:

  • Cancer
  • High cholesterol levels
  • Diabetes

Getting more selenium than you need through a supplement could be harmful. Americans generally get enough selenium from foods like whole grains and nuts. Brazil nuts are the richest source. One nut has more than the daily recommendation. Limit yourself to a couple per day.


Fenugreek is a member of the legume family. It has long been used in traditional Indian and Chinese medicine to treat many health problems. It is rich in fiber, flavonoids, and other compounds. Fenugreek is often sold as a dietary supplement (capsules, tablets, tinctures, and powders). Lab and animal studies have shown that fenugreek might help lower cholesterol and possibly have other heart benefits.

Fenugreek may lower cholesterol by preventing the absorption of dietary cholesterol in the intestine and by increasing bile secretion (cholesterol is a component of bile). But study results have been inconsistent.

One study3 found a significant drop in triglycerides in people consuming fenugreek seeds soaked in hot water, but no change in LDL cholesterol.

Fenugreek supplements could interact with blood thinners and cause gastrointestinal problems. And if they indeed lower blood sugar as claimed, they may be risky for people with diabetes who need to keep blood sugar in a tight range.

We recommend that you limit its use to cooking and skip the supplements as cardiovascular benefits are not proven.



  1. Ram Gordon. JAMA Internal Medicine, October, 2010.
  2. K Rees. Cochrane Review, January, 2013.
  3. Kassaian N. International Journal for Vitamin and Nutrition Research, January, 2009.