Q: I’ve just bought a pound of Ceylon cinnamon, since that is supposed to have the least coumarin and be best for lowering blood sugar. Unfortunately, I can’t find anything on dosage — just that “too high doses are risky.” Do you have specific recommendations? I am a woman of 67 who needs to lose about 30 pounds.

A: A pound of Ceylon cinnamon will last you a very long time. A systematic review and meta-analysis of 35 clinical trials found that doses of 1.5 grams or more of cinnamon lowered total cholesterol, triglycerides, LDL cholesterol and serum glucose and insulin (Critical Reviews in Food Science and Nutrition, March 19, 2021).

We were curious how to measure 1.5 grams of powdered cinnamon, so we got out our sensitive kitchen scales. We found that ¼ teaspoon weighed just over 2.5 grams (2.6 in one try, 2.8 in another, discrepancy no doubt due to kitchen measurement technique). We conclude that ¼ teaspoon cinnamon daily would be enough to help lower blood sugar if someone were following a sensible low-carb diet. Please have your health care provider monitor your progress.

You are correct that Ceylon cinnamon has the least coumarin, a compound found in some cinnamon bark that can be toxic to the liver (Plant Foods for Human Nutrition, December 2019). Overall, Ceylon cinnamon has the best activity profile for controlling blood sugar.

To learn more about natural approaches to controlling blood sugar, you may want to read our eGuide to Preventing & Treating Diabetes. This online resource is located under the Health eGuides tab at www.PeoplesPharmacy.com.

Q: You’ve published some anecdotes about vitamin B1 to repel mosquitoes, and I’ll add my story to your collection. The mosquitoes have been eating people alive this year far worse than usual, swarming, feeding in sunlight, like nothing I’ve ever seen before. I’ve been bitten mercilessly, as has my family.


I started taking thiamine as an experiment; the rest of my family has not. They’re still being bitten bloody, and I haven’t had more than three bites since two days after the first dose.

A: Thanks for your testimonial. For decades, anecdotes were all we had on this topic. Now, however, Egyptian scientists have come up with a topical formulation of vitamin B1 that is effective as a mosquito repellent (Journal of Pharmaceutical Sciences, Aug. 3, 2021). In this study, nanospheres of thiamine were applied to skin. Surprisingly, this hydrogel was as effective as DEET.

This doesn’t answer the question whether oral thiamine is an effective repellent, but it does suggest that there is something in this vitamin that mosquitoes don’t like.

Q: Why don’t you mention the Indian herb mix triphala for constipation? Triphala consists of haritaki, bibhitaki and amla. It is used in traditional Ayurvedic medicine to prevent disease and treat several symptoms, including constipation and inflammation.

A: Triphala (TLP) is indeed a popular Ayurvedic remedy. In fact, according to Dr. Deepak Chopra and his colleagues, this triple-fruit mixture “is a cornerstone of gastrointestinal and rejuvenative treatment” (Journal of Alternative and Complementary Medicine, Aug. 1, 2017). The polyphenols in these plants promote a healthy gut microbiome and encourage regularity.