Supplements and Diabetes Medicines: Low Blood Sugar Risk

Urgent first: signs of very low blood sugar

If someone with diabetes collapses, cannot be woken, cannot speak or see clearly, or has a seizure, call 911. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK, US) says severe low blood sugar "is dangerous and needs to be treated right away." [1] In its symptom table, milder signs include feeling shaky or jittery, hungry, tired, dizzy, lightheaded, confused or irritable, and symptoms "tend to come on quickly." [1]

The question this page answers

Can a herb or supplement change how diabetes medicines work, or add to their blood-sugar-lowering effect? The honest answer from the sources we read is: sometimes it may, but good interaction data are thin. A 2025 umbrella review (a review of reviews) of herbal medicines for type 2 diabetes said careful monitoring for low blood sugar is essential when herbal medicines are used with antidiabetic drugs, "given a current lack of data on herb-drug interactions." [2] Lack of data is not proof of safety.

Why low blood sugar is the concern

NIDDK explains that low blood glucose can be a side effect of insulin and some other diabetes medicines that help the pancreas release insulin. [1] Anything that also lowers blood sugar, or changes how a medicine is handled by the body, could in theory push levels lower. Whether that happens with a given product is usually not established, so this page labels each point.

What the sources say, by product

NCCIH also says there is no reliable evidence that any herbal supplement helps control diabetes or its complications, and that for a few supplements (chromium, cinnamon, berberine) there is only weak evidence of possible benefit. [3]

Things that make low blood sugar more likely

NIDDK lists not eating enough carbohydrates, skipping or delaying meals, fasting for a procedure, more physical activity than usual, drinking too much alcohol without enough food, and being sick. [1] NIDDK also says people age 65 or older, and people with kidney disease, heart disease or cognitive impairment, are more likely to develop low blood glucose. [1] A supplement added on top of any of these is a reason to speak with the care team first.

Kidneys

NCCIH notes that diabetes is the leading cause of kidney disease and that some supplements have been linked to kidney damage, so a provider should closely monitor supplement use for anyone with or at risk for kidney disease. [3]

Never replace treatment

NCCIH says it is "very important not to replace medical treatment for diabetes with an unproven health product or practice," and warns about products marketed as a "natural diabetes cure" or to "replace your diabetes medicine." [3]

What a reader can do

• Tell the prescriber and pharmacist about every herb, tea and supplement, including ones you take only sometimes. MedlinePlus says the doctor may need to adjust medicine amounts or monitor you for side effects. [6]
• Do not start, stop or change a diabetes medicine because of a supplement. Ask the prescriber or pharmacist.
• Ask how and when to check blood sugar if you add anything new.
• See the wider picture in How Interactions Work, Interactions by Drug Class and Vitamins, Blood Sugar and Diabetes.
• Product-specific pages: Berberine, Chromium and Cinnamon.
• Goal-level information: Prediabetes, Type 2 Diabetes and Metabolic Syndrome.