Does Metformin inhibit recovery and muscle building?

[Yonason Herschlag]

Hey Rip!

My endocrinologist recommended that I take Metformin (an insulin sensitizer) to help lower my blood sugar and to help me lose weight (I'm 53yrs 5'9" 230lbs, at about 26% body fat). After taking it for six weeks I found that it was killing my progress and making me weaker.

Is it true that Metformin inhibits muscle recovery?

I stopped taking the Metformin 3 days ago. When could I expect the muscle recovery return to normal?

Are there natural insulin sensitizers that could help my blood sugar levels without harming muscle recovery (such as Berberine, magnesium, and ginger)?


I thank you in advance for your advice.

[Mark Rippetoe]

I don't know. We'll ask.

[MBasic]

I don't know. We'll ask.

It's not looking good:

Up to this point, I haven’t addressed metformin directly, but have referred to sensitizers in general. Here’s where that changes. While the majority of sensitizers (including metformin) in use today work to increase insulin sensitivity via AMPK activation, metformin has other negative effects on androgen receptors which compound its negative effect on protein synthesis, the most problematic of which is its ability to reduce androgen receptor density. In other words, this stuff doesn’t just have a suppressive effect on androgen receptor function, it actually gets rid of them! Being that androgen receptor signaling is the primary mechanism through which testosterone and other steroids stimulate muscle growth, anything which eliminates this critical mediator not only reduces the rate of muscle growth, but total growth potential as well.

Metformin has also been proven to reduce endogenous testosterone production in both men and women—significantly.

[Mark Rippetoe]

Source?

[footrat]

I'm definitely watching this thread. My wife has PCOS, and has been on metformin since she was in high school for it.

[David Kirkham]

I too am extremely interested in this thread.

[Yonason Herschlag]

this stuff doesn’t just have a suppressive effect on androgen receptor function, it actually gets rid of them!

According to the claim that metformin gets rid of androgen receptors, does that mean with one pill of 250 mg taken once, all one's androgen receptors will disappear, or will it take ten years of 2500 mg daily to do that?

Metformin is the first-line medication for the treatment of type 2 diabetes, particularly in people who are overweight. It is probably the most popular medicine for type 2 diabetes, and the effects you mentioned are not listed as one of the side effects. So as Rip says, it would be helpful to bring a reliable source.

I had one heavy workout one week after stopping metformin, and it appears that I had a partial regain of strength. I'm hoping to reach full recovery by early next week. I was taking 1700 mg/d for six weeks. I am certainly hoping the damage is not permanent.

Anyways, since metformin is such a widely used drug, it is appropriate that the negative effects of weakening muscles become more well known, and I thank Rip for creating this platform for people to learn about such things.

Source?

One source I found so far:
"Conclusion: Metformin was effective in decreasing HOMA-IR, LH, free testosterone and the relative expression levels of AR. Furthermore, metformin might improve the systemic and local environment of the uterus caused by hyperandrogenemia in PCOS patients with insulin resistance."

But there is no clarity from this if the T reduction is merely temporary or permanent.

[Mark Rippetoe]

According to the claim that metformin gets rid of androgen receptors, does that mean with one pill of 250 mg taken once, all one's androgen receptors will disappear, or will it take ten years of 2500 mg daily to do that?

Cyanide doesn't work this well.

[jmelancon]

My experience with it--

I'm 35, have been training since September of 13, diagnosed type 2 diabetic in 2014. I've taken 2000mg of metformin a day since then. Despite this, and priorities in my life outside of training (I work 65-80 hours a week), I managed to deadlift 510, squat 475, bench 275, and press 185 at a body weight of 270. I subsequently lost a bunch of weight (thanks to a consult with Andy), and a little bit of strength with it.

I don't know how much the metformin impacted my numbers. I do know that lifting has kept me from being dependent on insulin, so there's that.

[Kiril]

I don't know how much the metformin impacted my numbers. I do know that lifting has kept me from being dependent on insulin, so there's that.

Don't you think that losing 30-50 pounds of your bw(I mean a fat, of course) would do a better job in keeping you from beginning the insulinotherapy?