Supplements and GLP1 Medications…to take or not to take? (June 2026)

People often think that dietary supplements are always safe, so may not consider that they may have potentially dangerous interactions with medications. I have written articles on drug nutrient interactions in prior months, but haven’t discussed which supplements to consider taking, and which to avoid, when taking a GLP-1 medication.  This article will discuss those recommendations.

Because people taking a GLP-1 generally consume fewer calories than they used to, it has been recommended to increase protein take and fiber. Increasing protein can help reduce muscle loss, while increasing fiber can help prevent constipation. When someone doesn’t consume enough calories and/or fiber, they may find it difficult to have a bowel movement, or to have a bowel movement the way they had in the past.

It’s impossible to predict what side effects, if any, someone will experience from any medication. However, there are a number of GLP-1 side effects that some of my clients have experienced. For example, when nausea results in vomiting, this causes a loss of potassium, so potassium levels may be lower than usual.  Also, absorption of vitamin B-12 and vitamin D may be lower than usual, leading to lower levels in the blood. These are areas where supplementation may be needed.

Interestingly, because GLP-1 medications slow the movement of food through the small intestine, this could also create an opportunity for increased absorption of certain supplements. For example, the herb turmeric (and its active component, curcumin) was suspected to have contributed to a case of drug-induced liver injury in someone taking a GLP-1, likely due to use of high-dose turmeric extract (3,000 mg per day standardized to 95% curcumin). Both turmeric and semaglutide have been shown to inhibit a pathway that regulates inflammation in the liver, and the slowing of movement through the small intestine could increase the opportunity for curcumin absorption.  Suffice to say that it may be advisable to avoid high dose supplementation with turmeric and/or curcumin when receiving GLP-1 medications.

A number of supplements—including cinnamon, ginseng, chromium picolinate, aloe vera, ashwagandha, bitter orange extract and ephedra—can decrease blood sugar levels. When taking these supplements along with GLP-1 drugs such as semaglutide, which also lowers blood sugar, people may require more frequent blood sugar monitoring and might require a dose adjustment of the GPL-1 medication.

Because many people take GLP-1 medications specifically to help manage their blood sugar, it’s important to know that several supplements can increase blood sugar, working against the GLP-1. Examples include:

• High doses of niacin.
• Prescription digestive enzymes (the enzymes may cause an increase or decrease in blood sugar levels in people with exocrine pancreatic insufficiency).
• CLA (conjugated linoleic acid), which may worsen blood sugar control in diabetics and in people in larger bodies without diabetes.
• Melatonin, which, when taken at bedtime, may worsen blood sugar control and insulin function after breakfast the following morning in people with type 2 diabetes. It may also temporarily worsen insulin function in healthy people without diabetes.
• Krill oil, which in large daily doses (providing a modest amount of EPA and DHA) has been shown to reduce insulin sensitivity in overweight, middle-aged men by about 27%, which can in turn increase blood sugar.
• Desiccated thyroid, a natural hormone replacement medication, may also interfere with blood sugar control.

The bottom line is that if you are on a GLP-1 medication, talk to your healthcare provider about what supplements you are taking, or are interested in taking, to help avoid any potential adverse interactions, and their side effects.

References

• Vuksan V, Xu ZZ, Jovanovski E, et al. Efficacy and safety of American ginseng (Panax quinquefolius L.) extract on glycemic control and cardiovascular risk factors in individuals with type 2 diabetes: a double-blind, randomized, cross-over clinical trial. Eur J Nutr. Apr 2019;58(3):1237-1245.
• McKennon SA. Non-Pharmaceutical Intervention Options For Type 2 Diabetes: Complementary & Integrative Health Approaches (Including Natural Products And Mind/Body Practices). 2024 Jul 6. Endotext [Internet]. South Dartmouth (MA): MDText.com,
• Mozaffarian D, Agarwal M, Aggarwal M, et al. Nutritional priorities to support GLP-1 therapy for obesity: A joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity (Silver Spring). 2025 Aug;33(8):1475-1503.
• Krietsch, B. Four Supplements to Avoid If You’re Taking a GLP-1 Medication, According to Dietitians. Eating Well, January 2026.