Drug & supplement interaction

Carnosine + Metformin XR

Metformin XR brand name: Glucophage XR.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Carnosine has a moderate interaction with Metformin XR. Theoretically, taking carnosine with antidiabetes drugs might increase the risk of hypoglycemia.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Carnosine and Metformin XR

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTIDIABETES DRUGS

Why this applies to Metformin XR

Metformin XR falls under ANTIDIABETES DRUGS — the group Carnosine interacts with.

Theoretically, taking carnosine with antidiabetes drugs might increase the risk of hypoglycemia.
Some, but not all, preliminary clinical research shows that carnosine might reduce fasting blood glucose levels.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist: carnosine itself may gently nudge your blood sugar downward. Some early human studies hint it can lower fasting glucose, though the picture isn't consistent. Since Metformin XR is already working to bring your numbers down, stacking carnosine on top could, in theory, push your sugar lower than you intend.

I want to be honest, this is a theoretical concern based mostly on how carnosine seems to act, not on strong studies with people taking both together. Plain metformin rarely causes true lows on its own, so the risk here is modest. Still, watch for signs like shakiness, sweating, dizziness, or sudden hunger. If you'd like to try carnosine, check in with your pharmacist or doctor first so your blood sugar can be monitored.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Karkabounas S, Papadopoulos N, Anastasiadou C, et al. Effects of a-lipoic Acid, carnosine, and thiamine supplementation in obese patients with type 2 diabetes mellitus: A randomized, double-blind study. J Med Food. 2018;21(12):1197-1203.
  2. Peng W, Mao P, Liu L, et al. Effect of carnosine supplementation on lipid profile, fasting blood glucose, HbA1C and insulin resistance: a systematic review and meta-analysis of long-term randomized controlled trials. Complement Ther Med 2020;48:102241. PubMed
  3. Siriwattanasit N, Satirapoj B, Supasyndh O. Effect of oral carnosine supplementation on urinary TGF-ß in diabetic nephropathy: a randomized controlled trial. BMC Nephrol 2021;22(1):236. PubMed
  4. Sureshkumar K, Durairaj M, Srinivasan K, et al. Effect of L-Carnosine in Patients with Age-Related Diseases: A Systematic Review and Meta-Analysis. Front Biosci (Landmark Ed) 2023;28(1):18. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Carnosine Also Interacts With Other Medications

Carnosine has 85 moderate known drug interactions in our database — the Metformin XR one above is one of them. If you take anything else, check it against the full list below.

Moderate 85 No known interaction 2,745 (incl. Metformin XR)
Taking anything else?

Check Another of Your Medications Against Carnosine

Covers the 2,830 medications we’ve checked against Carnosine. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Metformin XR

This page covers Carnosine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin XR page lists 256 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Siberian Cocklebur (major), Acai (moderate), African Wild Potato (moderate) and Agaricus Mushroom (moderate).

By severity: 2 major · 215 moderate · 39 minor.

From our pharmacist’s overview on the Metformin XR page

“Siberian cocklebur stands alone at the top of this list; its seeds have caused severe low blood sugar in humans, and no one taking metformin XR (Glucophage XR) should use it. Almost everything else here, 239 of the 256 ingredients, affects blood sugar too, so this list earns real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Metformin XR interaction page

One more smart check

Taking Carnosine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 407 real supplement products containing Carnosine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Carnosine. Your product may carry other ingredients that interact with Metformin XR too, on top of Carnosine — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Carnosine and Metformin XR Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Carnosine
Top half

#475 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Metformin XR
Top 25%

#430 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Carnosine

What is Carnosine?

  • Anti-aging and general wellness
  • Exercise performance and muscle support
  • Brain and cognitive health
  • Eye health (cataracts, with N-acetylcarnosine drops)
  • Antioxidant support

Carnosine is a naturally occurring dipeptide (made of beta-alanine and histidine) that acts as an antioxidant and buffer in muscle and brain. It is sold as an anti-aging and performance supplement, but human evidence for most uses is limited, and many studies actually use beta-alanine, its precursor. It appears generally well tolerated at common doses, but talk to your pharmacist or doctor before starting it.

Read the full Carnosine monograph & all interactions
Keep checking

Other Drugs & Carnosine

Browse every other medication we’ve checked against Carnosine — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
85Moderate
0Minor
2,744No known interaction
85 Moderate 2,744 No interaction
Moderate

85 interactions

Showing 60 of 85 moderate interactions — see all 85 on the Carnosine page.

No interaction 2,744 drugs checked — show the list

We also checked Carnosine against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,744 medications checked with no known interaction — see the full Carnosine list.

See the full Carnosine interactions page
See every supplement checked against Metformin XR, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Carnosine monograph › Uses, safety, and every drug interaction in one place Metformin XR supplement interactions › Every supplement checked against Metformin XR, ranked by severity Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Carnosine and Metformin XR Together: Common Questions

Can you take Carnosine with Metformin XR?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Carnosine and Metformin XR interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.