Metformin Adverse Effects: Be Aware of These Symptoms

Metformin, a low-cost, daily prescription medication, is widely used for treating Type 2 diabetes and high levels of insulin resistance. This medication comes in immediate and extended-release formulations and has off-label uses for treating polycystic ovary syndrome (PCOS) and helping induce weight loss for people living with prediabetes.

However, long-term use of metformin may lead to decreased vitamin B12 levels, a nutrient crucial for neurological health. This occurs because metformin interferes with the absorption of vitamin B12 in the intestine through several mechanisms.

If you don't have enough vitamin B12, that can lead to neuropathy, numbness and tingling of the hands and feet, and memory problems. To prevent deficiency-related neurological complications, monitoring vitamin B12 levels in patients on long-term metformin is important, and supplementation is safe and often recommended.

Metformin itself shows neuroprotective effects in experimental and clinical studies unrelated to B12 deficiency. It has been found to promote neurogenesis, reduce neuroinflammation, and protect against neuronal damage in animal models of neurodegenerative diseases. Metformin's diverse mitochondrial and anti-inflammatory actions may also support neural health and have shown potential benefits in mitochondrial-related optic neuropathies like Leber's hereditary optic neuropathy (LHON).

While metformin is neuroprotective in some contexts, vigilance for B12 deficiency is crucial to avoid negative neurological outcomes linked to low B12. If you have kidney disease or other kidney conditions, notify your healthcare provider before taking metformin, as lactic acidosis, a life-threatening condition caused by a pH imbalance and too much lactic acid in the bloodstream, is more likely to occur in people with reduced kidney function.

Hypoglycemia, or low blood sugar, can also be life-threatening and is more likely to occur if metformin is taken in combination with insulin or other diabetes medications like sulfonylureas. To reduce the chances of these side effects, taking metformin with food and starting out on smaller doses and increasing over time as needed can be recommended.

It's worth noting that metformin tends to come in larger pill form, so it may not be suitable for people who have difficulty swallowing pills. If you've taken metformin for four years or more, you're at higher risk for vitamin B12 deficiency.

In conclusion, while metformin plays a significant role in managing diabetes, it's essential to be aware of its potential impact on vitamin B12 levels and neurological health. Regular monitoring and supplementation, as advised by healthcare providers, can help mitigate these risks and ensure the safe and effective use of this important medication.