Metformin: What You Need to Know

Apr 22, 2020

Metformin Is Almost Always the First Medication Prescribed for Type 2 Diabetes

Chances are, if you have Type 2 Diabetes, you've taken Metformin. All the major medical organizations recommend Metformin as the first medication to treat Type 2. There are a few reasons for this:

  1. It's effective. I mean, it works really, really well!
  2. It's dirt cheap. It's on the $4 list at pharmacies that have one and most insurance companies cover it with minimal or no copay. 
  3. It's safe, with very few exceptions, that I'll go into below.
  4. It's well-tolerated by most people.
  5. Did I mention that it works? And it's cheap? And safe? And most people don't have side effects?

Why Do We Love Metformin?

Metformin is REALLY Cheap. While most Type 2 Diabetes drugs can run $300-$800 or more per month, Metformin is almost always under $10-20 a month. If it's more expensive than that for you, here are a couple tips that might make it a little cheaper:

  1. Your insurance company may be charging you a copay. Sometimes the copay is higher than the cash price of the drug. Ask the pharmacy to charge you for your metformin at the cash-pay price.
  2. Check out This website or app will tell you where to take your prescription to get the best price near you. If you need a coupon, the coupon will be provided. 

Metformin works in three ways: 

  1. It improves Insulin Resistance. (We talked about Insulin Resistance in this blog post.)
  2. It reduces how much sugar is absorbed from the food you eat.
  3. It decreases your liver's production of sugar. (Did I mention that your liver MAKES sugar, even if you're not eating any? This is a topic for another time, but suffice it to say, Metformin slows this process down.)

Metformin is really safe for most people. In fact, because it's so safe and effective, I have doctor friend who jokes that he thinks metformin should be added to the municipal water supply. People who should avoid Metformin are people with severe kidney disease or metabolic acidosis (for which they would generally be hospitalized). So, not reasons that would prevent most of us from safely taking Metformin. 

Besides effectively lowering blood sugar, many people lose weight and/or see an increase in their energy level. Remember the part above where I said that that it improves insulin resistance? And remember that insulin resistance causes sugar to move to fat storage instead of going to the muscle cells where it's used for energy? Well, Metformin helps redirect the sugar to where it's needed. Now your muscles are getting the energy they need and the sugar isn't going directly to fat storage. Win-Win, right?

It Can't All Be Puppies and Sunshine. What's the Downside of Metformin?

Metformin is the most discontinued drug taken by people with Type 2 Diabetes. What's up with that? There are a lot of things the prescriber might not tell you about Metformin that can make your time with Metformin less-than-pleasant. It's not that they're trying to keep things a secret, it's more likely that they don't know that Metformin is a difficult drug to take or, if they do, they forget to mention it, what with all the other things they need to talk to you about in the 10 minutes you have together. So, let's cover some of the basics so you can have an easier time with Metformin and not become a "non-compliant" statistic.

The main reason people stop Metformin is the well-known GI Side Effects. That's the polite term for it. This can range anywhere from a little bit of gas and bloating to REALLY bad stomach cramps and disabling diarrhea. For most people, the severe side effects can be avoided with a few tweaks to the way Metformin is taken. Here are some things you can do to improve your chances of avoiding the nasty side effects (note that some of them require your prescriber to alter their prescription so you need to make sure they're on board):

  1. Start low and go slow. The usual dose of Metformin is 1000-2000 mg daily, with the higher dose being the goal for most people. If you start taking 2000 mg of Metformin without a ramp-up period, you're pretty much guaranteed to have a TERRIBLE time. Unfortunately, a lot of prescribers forget to start slow. If they're not already doing so, ask your prescriber or the pharmacist about starting with just 500 mg a day until all your GI side effects have stopped and then increasing to 1000 mg a day, then 1500 mg, until eventually reaching 2000 mg. This method may take a month or two but is more likely to result in reaching the right dose without you needing to stop taking the Metformin completely due to side effects that you just can't live with. If you DO reach a dose where the side effects are intolerable, be sure to talk to your prescriber and talk about stepping down to the previous dose where you DID tolerate it. Taking a partial dose is usually better than none at all. 
  2. Ask to start with the extended release version instead of the regular version (Metformin ER). Many prescribers aren't in the habit of ordering it this way because it used to be MUCH more expensive to do so and they may not realize that the extended release version tends to be gentler on the stomach than the regular version. There is no longer much difference in price and Metformin ER is now on most $4 lists.
  3. The prescription will usually instruct you to take it twice a day, with meals. For some people, taking it all at the same time at another time of day (usually bedtime) works best for them. Before trying this, check with your prescriber or pharmacist because there may be a specific reason they want you taking it the way it's directed. Also, this is only okay with the extended release version.
  4. Reduce your carbohydrate and/or dairy intake. Many people who take Metformin find they have diarrhea after eating a high-carb or sugary meal. Some people notice this with dairy as well.
  5. Ask your provider if there's anything you can take/do to prevent the diarrhea symptoms. Some providers may recommend fiber supplements or other over-the-counter or prescription medication to help short-term.

A note about prescribers and Metformin: Many prescribers have NO IDEA how bad the side effects of Metformin can be. I've been at conferences where I've heard the lines "Some patients will stop taking their Metformin because they have a little bit of diarrhea. It's important that you stress the importance of continuing despite these bothersome side effects."

Um. Hello. Bothersome side effects? I've taken Metformin. When I took it, the side effects severely limited my life. I couldn't go for walks longer than a block because I knew there was a risk I wouldn't make it home in time. I didn't just have "a little bit of diarrhea." I pooped water multiple times per day, leaving me with headaches from dehydration. Based on my own anecdotal surveys of my own patients, I know that my experience isn't typical but it also isn't unusual. Most people who follow the tips above, tolerate Metformin just fine after a 1-2 week period of adjustment with each dose increase.

Anything Else Important to Know About Metformin?

Metformin can cause B12 Deficiency in some people. You can talk to your healthcare provider about taking an over-the-counter B12 supplement. This is important to note because B12 Deficiency can cause peripheral neuropathy, which is also a complication of Diabetes. B12 neuropathy can be mistaken for Diabetic neuropathy. While this might not seem like a big deal, it is, because B12 neuropathy can be treated with B12 supplementation if caught early enough.

What's the Bottom Line on Metformin?

Metformin is probably the best and safest drug available for Type 2 Diabetes but is has some serious drawbacks due to potentially severe stomach side effects. I think it's absolutely worthwhile to try Metformin if it's recommended by your medical provider. It's worth the trouble of sticking it out through the side effects for a few weeks to see if you can make it work and continuing to titrate up to your prescriber's recommend dosage.

Most People Do Fine on Metformin, After a Short Adjustment Period!

It's REALLY IMPORTANT to be open with your prescriber about side effects you have with Metformin or any other drug. I mentioned above that most providers have no idea how bad the side effects can be. I think this is because no one wants to talk about diarrhea. If you're pooping water, tell them that you're pooping water! If you can't go out to dinner because you might not make it through the drive home, tell them! Prescribers keep prescribing Metformin to people who keep not taking it because patients are embarrassed to talk about how bad the diarrhea is. My own patients have told me, "I'm having some stomach trouble" and would have left it there if I didn't prod more to find out how bad it was. Tell them! Severe diarrhea is serious, not a "bothersome side effect." If you're among the small percentage of people for whom Metformin really doesn't work despite trying the measures I listed above, your medical provider needs to know and they need to find an alternative. Metformin may be the first option, but it's not the only option.


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