Based on NIH | Are there increased side effects or risks from eating nuts while taking metformin?

There is no evidence that eating nuts increases side effects or risks from metformin. In fact, metformin is typically recommended to be taken with food to lessen stomach upset, and nuts can be part of that meal or snack without a known drug–food interaction. Food in general slightly delays and reduces metformin absorption, which often helps tolerate it better, and this effect is expected with any meal components, not specifically nuts. ^[1] Taking metformin with meals is a standard way to reduce common gastrointestinal symptoms like nausea or diarrhea. ^{[2] [3] [4] [5]}

What we know about metformin and food

• Metformin’s absorption is decreased and slightly delayed when taken with food, leading to a lower peak level in the blood and a later time to peak. ^{[1] [6] [7] [8]} This change is not harmful and is often used on purpose to reduce stomach side effects. ^{[2] [3] [5]}
• Guidance consistently advises taking metformin with meals and starting with a low dose, then increasing slowly, to minimize gastrointestinal symptoms. ^{[9] [2] [3]}

Do nuts specifically interact with metformin?

• There is no documented interaction between nuts (including almonds, walnuts, peanuts, pistachios, etc.) and metformin in official prescribing information. ^{[1] [9]}
• The known dietary caution with metformin is alcohol, because heavy drinking can raise the risk of lactic acidosis; this warning is unrelated to nuts. ^{[10] [11]}

Common side effects and how food helps

• The most common side effects of metformin are gastrointestinal: diarrhea, nausea, and upset stomach. ^{[2] [3] [5]} Taking metformin with food helps many people tolerate it better. ^{[2] [3] [5]}
• If GI symptoms appear later after you’ve been stable on metformin for a while, your clinician may consider other causes. ^{[12] [13]}

Practical tips if you enjoy nuts

• It’s reasonable to take metformin with a balanced meal or snack that may include nuts, as part of fiber, protein, and healthy fat that can be gentler on the stomach. ^{[2] [3]}
• Watch alcohol intake, since that not nuts is the relevant dietary risk with metformin. ^{[10] [11]}
• If you are combining metformin with insulin or a sulfonylurea, low blood sugar can occur, and including a source of calories (a meal or snack) is helpful; nuts can be part of that snack. ^{[14] [15] [16]}

Bottom line

• Nuts do not have a known harmful interaction with metformin, and including them in meals may be compatible with strategies used to reduce metformin’s stomach side effects. ^{[1] [2] [3]} The key diet caution with metformin is to avoid excessive alcohol due to lactic acidosis risk. ^{[10] [11]}

Would you like suggestions for metformin-friendly meal or snack ideas that include nuts?