Metformin has been used for decades to manage blood sugar in type 2 diabetes. Metformin decreases the amount of glucose absorbed through your intestines and the amount produced in your liver. Metformin also improves your body’s sensitivity to insulin, making it easier for cells to transport glucose from the blood into cells where it can be used for energy.

The most serious potential side-effect of metformin is lactic acidosis. Lactic acidosis can be life-threatening, so it is important to let your healthcare provider know if you have a history of kidney disease. Other risk factors for lactic acidosis include being over age 65 or having a history of:

• Heart attack
• Coma
• Heart disease
• Stroke

Some medications can also increase your risk of metabolic acidosis, so it’s important to tell your healthcare provider about every medication you are taking.

Metabolic acidosis is a serious potential side-effect of metformin that may occur in some high-risk patients. Symptoms associated with lactic acidosis include:

• Extreme tiredness
• Weakness or pain
• Nausea
• Vomiting
• Stomach pain
• Decreased appetite
• Rapid or deep breathing
• Shortness of breath
• Dizziness
• Lightheadedness
• Abnormally fast or slow heartbeat
• Skin flushing
• Muscle pain
• Feeling cold, especially hands or feet

Let your healthcare provider and pharmacist know if you are taking any medications (over-the-counter or prescriptions) to ensure that any medications you are taking do not interact with metformin. Prescription medications that have the potential to increase lactic acid are a concern, including some anticancer, antimicrobial, and HIV medications.

Excess alcohol consumption is a risk factor for lactic acidosis, the most serious (though uncommon) potential side-effect of taking metformin. If you drink alcohol in excess, generally defined as more than one drink per day for women or two drinks per day for men, let your healthcare provider know.

Researchers found that combining leucine, sildenafil, and metformin worked better than metformin alone at activating the SIRT 1 pathway. The SIRT 1 pathway is a key pathway that regulates glucose and fat metabolism in the liver. Leucine directly stimulates the SIRT1 pathway, and sildenafil increases nitric oxide, which increases blood flow.

Weight loss from metformin alone is a gradual process. The average weight loss is 5 to 6 pounds. This is why metformin is combined with leucine, vitamin B12, and sildenafil. It is also important to consume a healthy diet and engage in physical activity. Metformin synergy supports your weight loss efforts.

Yes, metformin can cause nausea and upset stomach. However, for most people, these symptoms improve within two weeks. It is important to let your healthcare provider know about any symptoms you may be experiencing.

Yes, sildenafil (Viagra, Revatio) is used to treat erectile dysfunction. Sildenafil is a type of phosphodiesterase inhibitor. By inhibiting the breakdown of phosphodiesterase, nitric acid is active longer. Nitric oxide relaxes smooth muscle and dilates blood vessels which increases blood flow. In addition, sildenafil was found to help metformin activate the SIRT 1 pathway.