Is blood sugar raised on rapamycin?

I feel as if my blood sugar is less under control on rapamycin and I have put on weight in the 3 weeks since I’ve been taking it. Has anyone else had this experience or is it just a coincidence? Thanks

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Rapamycin can raise your blood sugar/glucose levels. Its a common side effect , less common at the aging weekly dose but still can happen to some folks. My blood sugar is pretty stable on rapamycin. Do you have diabetes and if you do , are you taking any meds such as metformin? and what dose of rapamycin are you taking?


See these threads from the past:

Here: About the increase in blood lipids and blood sugar caused by Rapamycin

Here: Blood Sugar On Rapamycin

Here: Does Sirolimus reduce or increase Insulin Levels?


I’ve gained 10 pounds since starting rapamycin. I feel your pain :slight_smile:


:weary::weary: Oh no that’s terrible. I can’t continue with this then… Devastated.

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This is my third week… 1mg, then 2mg, then 3mg. I was going to stick at 3mg but this week I noticed that my blood sugar must be up because I’m craving carbs, putting on weight and biting my nails (which I do when my blood sugar fluctuates).

Usually I take 500mg metformin twice a day for pre-diabetes but I swopped it for Berberine which has the same effect a month ago. So I’ve been on two Berberine a day along with the rapamycin.

Do you think that Metformin is a better antidote for rapamycin than Berberine? In which case I could try swopping back to metformin.

Otherwise I have to give up on rapamycin. Which is very disappointing.

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Or alternatively take rapamycin less frequently perhaps accompanied by a fast. Each exercise of spring cleaning/mitophagy/autophagy has benefits.

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I haven’t gained any weight on Rapamycin. In fact, I’ve lost weight with Rapamycin + Acarbose. The Acarbose did it because it made me bloated and my appetite decreased.

Rapamycin will raise your blood sugar which is why I use the Metformin and Acarbose with it.

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I don’t want to take rapamycin (with metformin) if it is going to cause me higher blood sugar levels. I’m wondering if reducing dose/frequency will still have a beneficial effect on energy and no impact on blood sugar level. Any idea?

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The impact on blood sugar levels occurs when rapamycin is in the system. If it is not in your system in any quantity for a larger proportion of the time most of the time it will have no effect.


I feel as if my blood sugar is less under control

How do you know for sure? Did you test it?

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No I didn’t bother because I know my symptoms when my blood sugar is fluctuating.

Why not just test it instead of guessing?
Some of the home glucometers are fairly accurate and cheap.
Also, if you are gaining weight perhaps you are eating more causing your blood sugar to increase.

You may wish to drop the berberine while on rapamycin. “The combined use of rapamycin and berberine was found to have a synergistic cytotoxic effect, with berberine observed to maintain the cyotoxic effect of rapamycin on HCC cells at a lower rapamycin concentration.” Berberine sensitizes rapamycin‑mediated human hepatoma cell death in vitro - PubMed It also can act like grapefruit in increasing rapamycin levels. Perhaps metformin would be a better alternative. You could have quite high blood levels of rapamycin given co-factors.

I find that rapamycin does increase my appetite in odd ways on dosage days. I try to carve out an eating period where I eat low protein and low glycemic foods. Drop your dosage until you mitigate the higher risk you seem to have with blood sugar. Low dosage has many benefits.


I have a glucometer in a drawer but after 40 years of blood sugar monitoring I don’t need a meter to tell me when it’s gone up.

Thanks for this. I didn’t know about Berberine! I was giving Metformin a break. Back to metformin then …

I don’t understand. The paper is about the synergistic anticancer effect of combined rapamycin and berberine.
Do you think this is a bad thing? If so please explain.
Unlike chemotherapy rapamycin and berberine are not killing the good cells.

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Good point. I used the source to point out that blood levels of rapamycin could rise in synergy with berberine. A better example of its interactions with rapamycin, similar to grapefruit, @ Repeated administration of berberine inhibits cytochromes P450 in humans - PubMed. " Conclusions: Repeated administration of berberine (300 mg, t.i.d., p.o.) decreased CYP2D6, 2C9, and CYP3A4 activities. Drug-drug interactions should be considered when berberine is administered." CYP3A4 is the same enzyme inhibited by grapefruit and berberine.

PS - Berberine also acts an antifungal. Since rapamycin is also an antifungal, who knows the benefits or risks in combining the 2?

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Don’t know for sure, but I have been combining the two for approx. 20 months. Though I take rapamycin in the morning and berberine before supper.

I tend to avoid it around the time I take rapamycin. But I haven’t done any research that would offer a concrete assessment similar to what you can find with grapefruit and rapamycin. In addition, as a supplement, there can be differing degrees of quality and quantity of berberine. Maybe in your case it cancels out - raises levels of rapamycin and lowers blood sugar at the same time.