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CL Answer

Which supplements and foods can help lower or control blood sugar?

Find out which supplements can help lower or control blood sugar. Supplements including turmeric/curcumin, fiber, cinnamon, and ginseng are believed to help lower blood sugar.

Blood Sugar Control -- blood test and blood sugar chart

Clinical Update


Vitamin D and Prediabetes

Can vitamin D supplementation improve insulin resistance in people with prediabetes? See what a recent study found in the Prediabetes section of our Vitamin D Supplements Review. Also, see our Top Picks for vitamin D.

Product Review

Cinnamon Supplements and Spices Review

CAUTION: Some Cinnamon Products High in Toxin. See Which Passed or Failed and our Top Picks! .

Cinnamon Supplements and Spices Tested by

Product Review

Magnesium Supplements Review (Including Calcium, Boron, and Vitamins D & K)

Find Out What Magnesium Does, Who Needs It, and Our Top Picks Among Supplements

Clinical Update


Cinnamon for Lowering Blood Sugar?

Does taking cinnamon powder or extract help control blood sugar levels in people with prediabetes or type 2 diabetes? See what the latest study, and earlier studies, have found in the Blood sugar, type 2 diabetes and prediabetes of our Cinnamon Supplements Review.

Also see: Which supplements and foods can help lower or control my blood sugar?

Clinical Update


Magnesium Helps in Prediabetes

A recent study in people with prediabetes who were deficient in magnesium showed that a daily dose of magnesium significantly improved their glucose status. Details, along with our recent tests of magnesium supplements, are found in the Magnesium Supplements Review »

Clinical Update


Berberine for Prediabetes?

Does taking berberine help lower blood sugar and cholesterol in people with prediabetes? Find out what a recent study showed the Berberine section of our Berberine and Goldenseal Supplements Review.

Also see: Which supplements and foods can help lower or control blood sugar?

Product Review

Turmeric and Curcumin Supplements and Spices Review

See Our Top Picks Among Turmeric Products

Product Review

NAD Booster Supplements Review (NAD+/NADH, Nicotinamide Riboside, and NMN)

How Important Is Boosting NAD+ Levels? Find Out and Learn How Booster Supplements Compare.

NAD Boosters (NAD+/NADH, Nicotinamide Ribose, and NMN)

Product Review

Vitamin D Supplements Review (Including Calcium, Magnesium, Boron, and Vitamin K)

Find the Best Vitamin D Supplement with the Right Dose

Clinical Update


Black Seed Oil for Blood Sugar Control?

Find out if black seed oil improved blood sugar control in people with prediabetes in our updated answer to the question: What are the health benefits of black cumin seed (black seed) oil?

Clinical Update


Vitamin D & Diabetes Risk

In people with prediabetes, does taking vitamin D improve blood sugar regulation and decrease diabetes risk? Find out what a recent study showed in the Diabetes, insulin resistance and glucose control section of our Vitamin D Supplements Review.

Also see our Top Picks for vitamin D.

Clinical Update


Curcumin May Help Prevent Diabetes

Past research has suggested a potential role for curcumin (from turmeric) in blood sugar control. A recently published placebo-controlled study of curcumin given daily to people with prediabetes (those with blood sugar levels somewhat higher than normal) produced dramatic results in reducing the percentage of such individuals progressing to diabetes. Get the details in the latest update to's Turmeric and Curcumin Supplements Review -- which includes quality ratings of products and other potential uses of curcumin. More >>

Clinical Update


Cinnamon for Prediabetes?

Does taking a daily cinnamon supplement help control blood sugar in people with pre-diabetes? See the results of a recent study in the What It Does section of the Cinnamon Supplements & Spices Review. Also see our Top Picks among cinnamon supplements and among cinnamon spices.

Product Review

Tuna, Salmon, Sardines & Herring Review (Canned and Packaged)

Recalls & Warnings


FDA Warns Ten Sellers of "Diabetes" Supplements

On September 7, 2021, the FDA issued warning letters to 10 supplement companies that made drug claims by promoting products to treat diabetes and/or lower blood sugar. Five of the products were sold on Amazon as well as on company websites. The products were promoted with statements such as

CL Answer

Do any supplements naturally suppress appetite and help with weight loss?

Learn which natural ingredients can suppress appetite and find if these natural appetite suppressants help with weight loss.

Container of natural appetite suppressant supplement with measuring tape and scale in background

CL Answer

What are the health benefits of black cumin seed (black seed) oil?

Find out if black seed oil has health benefits, such as lowering blood pressure or cholesterol, asthma, weight loss, and others. Dosage, forms, including black seed oil and black seed powder, safety information, using black seed oil in foods and more.'s answer explains.

Black seed oil benefits -- bowl of black cumin seeds and bottle of oil

CL Answer

Which supplements can help to lower blood pressure?

Supplements to lower blood pressure, including CoQ10, vitamin C, fish oil, and olive oil, are all explored to find out what works.

Supplements that can lower, or raise blood pressure -- blood pressure cuff and bottle of pills

News Release


Best Magnesium Supplements Identified by ConsumerLab

  White Plains, New York, May 12, 2022 — Nearly half the U.S. population does not get adequate amounts of magnesium and can benefit from increasing magnesium intake from foods or supplementation.

News Release


Cinnamon Spices and Supplements Found to Vary Widely in Levels of Potentially Helpful and Harmful Compounds Reports

White Plains, New York, January 5, 2016 — Cinnamon supplements may be helpful for controlling blood sugar in people with type 2 diabetes or prediabetes, possibly due to compounds known as proanthocyanidins or PACs.

Recalls & Warnings


Seller of Curcumin, Garcinia, Glucosamine and More Warned for Manufacturing Violations

On September 7, 2018, the FDA issued a warning letter to Best Nutrition Products, Inc.