Many Americans take dietary supplements, but people with diabetes need to be cautious: several common supplements can change blood glucose, interact with medications, or carry other risks. This article reviews types of supplements people use, how they are regulated, and which specific products experts warn people with diabetes to avoid or discuss with their clinician. It highlights direct quotes from clinicians and national guidance so readers can weigh potential harms against unproven benefits.
Dietary supplements cover a wide range of products — vitamins, minerals, herbs, amino acids and probiotics — and they are often marketed to support immune health, energy, weight or blood sugar control. A large share of adults report using supplements regularly, so the chance of interactions with prescription diabetes drugs is real and common. Knowing which supplements can raise or lower blood sugar or change how medicines are metabolized matters for safety.
Unlike prescription medicines and many over-the-counter drugs, most supplements are not evaluated by the FDA for safety and efficacy before they are sold. The agency can act if products are unsafe or mislabeled, but quality and composition can vary greatly between brands and batches. That inconsistency is why experts urge caution when people with diabetes consider nonprescription remedies.
St. John’s Wort is one supplement people with diabetes are often told to avoid because it affects how the liver breaks down many drugs. “This herbal remedy can interfere with many diabetes medications by affecting the way the body breaks them down,” Menning told Fox News Digital. “Taking this supplement with insulin or oral diabetes medications may increase the risk of hypoglycemia,” she cautioned. Because of those interactions, adding this herb can make glucose control unpredictable.
Bitter melon and similar plant extracts are sold as natural blood sugar helpers, and they contain active compounds that seem to act on glucose metabolism. It contains compounds such as polypeptide-p, which may act like insulin. That insulin-like activity can amplify prescribed diabetes drugs and push blood sugar too low when used together, so anyone trying these products should do so only under close medical supervision.
High-dose niacin is another supplement with real drawbacks for people managing diabetes. “I would caution against using high-dose niacin supplements because it can noticeably raise blood sugar levels and make it harder to keep A1c in an optimal range,” Michelle Routhenstein told Fox News Digital. Nicotinic acid variants used in large amounts can blunt glucose control and interfere with diabetes medications, so the trade-off for cholesterol benefits may not be worth it for many patients.
Asian ginseng is promoted for energy and metabolic benefits, and some small studies suggest it can affect cardiometabolic markers. However, it also has the potential to lower blood sugar, especially when combined with diabetes drugs, which raises the risk of hypoglycemia. Anyone using ginseng should monitor glucose closely and alert their provider about any changes in symptoms or readings.
Beta-carotene is marketed as an antioxidant and vision-supporting supplement, but professional groups caution against routine use in diabetes. “The American Diabetes Association recommends against β-carotene supplementation for people with diabetes because of its association with increased lung cancer and cardiovascular mortality risk,” Jordan Hill told Fox News Digital. Where there is no documented deficiency, adding this antioxidant pill is not a safe default strategy.
Cinnamon often appears in headlines as a simple sugar-lowering remedy, yet it carries measurable risks at high intake. Consuming large amounts of cinnamon can push blood sugar too low and contains coumarin, a compound that can harm the liver if taken in excess. Casual stacking of cinnamon with prescription drugs is not a harmless practice and can complicate diabetes management.
Oral aloe vera and other popular botanical remedies are also flagged for caution because they may reduce blood sugar and cause gastrointestinal side effects when combined with medications. “These doses can even raise blood sugar levels in people who don’t have diabetes,” the NIH states when discussing high-dose niacin, illustrating how supplements can have unexpected effects on glucose even in otherwise healthy people. The message from specialists is consistent: supplements are not guaranteed safe.
The evidence for many supplements improving diabetes outcomes is limited or conflicting, and major organizations urge restraint. “Without underlying deficiency, there are no benefits from herbal or nonherbal (i.e., vitamin or mineral) supplementation for people with diabetes.” The primary concern with most supplements is not direct harm, but rather the lack of regulatory oversight, he told Fox News Digital. Before adding any supplement, speak with your diabetes care team so medication doses, monitoring and risks can be adjusted and tracked.
