Can you take metformin 4000mg daily? (+3 risks)

In this article, we will discuss whether you can take 4000mg of metformin daily or not. We will explain what are the risks of taking this dosage and how much metformin is safe to take.

Can you take metformin 4000mg daily?

No, you cannot take metformin 4000mg daily. The maximum dosage of metformin that is safe to take is 2000mg per day. It can be taken in 4 divided doses of 500mg when oral tablets are given.

Whereas if you are taking liquid dosing, you should take 5ml doses of 500mg or 1000mg. Sachets come in doses of 500mg or 1g (1).

Metformin is an antidiabetic agent that is used in the treatment and management of diabetes, PCOS, and other related conditions. It helps to regulate your blood sugar levels and insulin (2).

You cannot take 4000 mg of metformin because it exceeds the maximum recommended dose. Taking a medication more than the maximum recommended dose can lead to serious side effects and consequences. 

What are the risks of taking metformin 4000mg? 

Accidentally taking another dose or any incidence that leads up to you taking 4000mg/dose is not going to cause you any harm if it is a one-time thing. The lethal dose of metformin is 35 grams or 35000mg. 

In regards to this, 4000mg is not a serious overdose. However, consistently taking metformin above 2000mg/day increases the risk of adverse effects. It will cause hyperglycemia and lactic acidosis (2).

However, if you take 4000 mg of metformin daily, it can lead to the following adverse effects: 

Hypoglycemia: 

Metformin itself does not cause hypoglycemia, as it does not influence how much insulin is being secreted nor has an effect on how much insulin is present in the blood. 

However, the lactic acidosis that might occur due to metformin overdosage or toxicity might lead to hypoglycemia (5).

Gastrointestinal side effects: 

The primary adverse effects associated with metformin are gastrointestinal disturbances. These include nausea, vomiting, diarrhea, and upset stomach. 

In case of metformin overdose, these symptoms get worse. Patients have severe abdominal pain and constant vomiting which might lead to the onset of more severe symptoms if other co-morbidities are present (5).

Increased risk of vitamin B12 deficiency: 

Metformin increases the risk of vitamin B12 deficiency because it impairs the ability of the GI to absorb it. Taking a high dosage of metformin daily increases the risk of vitamin B12 deficiency and related symptoms like mouth sores (5).

Increased risk of lactic acidosis: 

Metformin inhibits mitochondrial respiration which leads to an increase in cellular lactate levels, because of the shift to anaerobic mechanisms. Metformin also affects gluconeogenesis (6)

It stops an enzyme called pyruvate carboxylase, inhibiting the first stepping, and ultimately preventing gluconeogenesis. This leads to an increase in the susceptibility of patients to develop lactic acidosis (6). 

The lactic acidosis seen in patients is mostly of mixed type, depending on the severity of the underlying diseases, genetics of the patient as well as the dose of metformin taken that determines the prognosis (6).

Is a 4000mg dose of metformin lethal? 

No, 4000mg is not lethal and does not lead to overdose. It is hard to accidentally take a lethal dose of metformin, which is around 35000mg. Cases have been reported from survival even after the ingestion of 60000mg/dose (5).

There have been two reported cases in which there was a deliberate attempt of suicide using metformin. In both cases, patients presented with symptoms of severe vomiting, lactic acidosis, and hemolytic anemia (5).

However, the cases of metformin being lethal at a dose of 4000 mg are not reported. Thus, taking this dose is not lethal but can lead to adverse effects if taken consistently. 

What to do if you have taken 4000 mg of metformin? 

As explained above, 4000mg of metformin is not a lethal dose. However, it might cause you to experience certain effects in some cases.

Monitor your blood sugar levels, check every 2 to 3 hours, and have a proper meal. Take food every few hours so hypoglycemia can be prevented.

Use a pillbox or use a medicine tracker so you don’t accidentally overdose or miss any dose.

How do I take metformin safely?

When you begin taking metformin, you will be advised to take it slowly. In this way, you will get the least side effects possible. You can take it in the following manner (1): 

In my experience

As per my experience, you should not take more than the dose of metformin prescribed by your doctor. The maximum dose of metformin that should be ingested should not be more than 2000mg/day.

It is not problematic if you accidentally take 4000mg/day of metformin. It does not cause any serious adverse effects or toxicity. However, taking this dose daily can lead to several risks like lactic acidosis, hypoglycemia, and GI side effects. 

In case of taking more than 2000mg of metformin in a day, check your blood sugar levels and eat balanced meals. Monitor yourself for any unusual symptoms and consult your healthcare provider if needed.

References