Ask Dr. Mike: Carnosine, Resveratrol & Do Your Supplements Impact Your Medications?

Here you'll find the answers to a wealth of health and wellness questions posed by Healthy Talk fans. Listen in because what you know helps ensure healthy choices you can live with. Today on Healthy Talk, you wanted to know:

Hello Dr. Mike, I'm a big fan of your show. First question is Carnosine. They say that it's a dipeptide, and I have learned that dipeptides are digested into amino acids. So, Carnosine will not survive as Carnosine in the digestion process. Is this supplement therefore a gimmick?

Carnosine is naturally produced in your body, found mostly in your muscle tissue and brain. There is a synthetic form that is sold as a supplement and can be used as a natural way to help cure high blood pressure, prevent cataracts, improve your eyesight, fight your wrinkles, and so much more.

Caronsine does in fact survive the digestion process because the enzymes that break down peptides don't act on dipeptides. They break down larger and larger proteins into smaller peptides that are absorbed into your body.

I have resveratrol from a Japanese knotweed. I heard some supplement manufacturer emphasized that theirs is not from knotweed. Does this mean knotweed is inferior?

No, resveratrol is a compound found in natural plants as well as in tons of dietary sources.

If you're wondering about the label, don't hesitate to call the manufacturing company and ask for their certificate of analysis. If a person on the other line is hesitant or doesn't know what that is, you probably should consider using a different brand.

How do I ascertain if a supplement will adversely impact my pharmaceutical medications?

There are very few dangerous interactions between drugs and supplements. However, to be on the safe side, you might want to check

If you have a health question or concern, Dr. Mike encourages you to write him at This email address is being protected from spambots. You need JavaScript enabled to view it. or call in, toll-free, to the LIVE radio show (1.844.305.7800) so he can provide you with support and helpful advice.

RadioMD Presents:Healthy Talk | Original Air Date: March 24, 2015
Host: Michael Smith, MD

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DR. MIKE: So, my first question is about carnosine. This came from a listener. It was an email question. This email address is being protected from spambots. You need JavaScript enabled to view it. and this is from R.F.

R.F. says, "Hello, Dr. Mike. I'm a big fan of your show, so here are my two questions. First, carnosine. They say it is a dipeptide. Now, I have learned that peptides are digested into amino acids, so carnosine will not survive as carnosine in the digestion process. Is this supplement, therefore, a gimmick?"

So, R.F. Great question. Yes, you're right. Carnosine is a dipeptide. It's made up of two amino acids—alanine and histidine, but it does survive the digestive process because the enzymes that break down peptides, they're called peptidases, proteases, they do not act on dipeptides. So, they break down larger and larger proteins into smaller peptides that are then, absorbed. Then, from there, the body processes them further once they are in the cell and stuff. So, alanine and histidine do survive the digestion process. As a matter of fact, I've had this question before, R.F., because I went back and found this research that comes from the 1990's. It was presented or published in the Journal of Physiology and they were looking at this very thing. So, people are doing more protein supplements. People are doing things like carnosine. So, they were looking, in the 90's, at how these proteins were really managed in the body. What they found was that the complete digestion of the protein doesn't always take place in the gut, that it actually...There was further processing within the cell itself. What they found in the journal of physiology in 1991 was that there was...Well, let me explain what they did. They took carnosine, which was one of the dipeptides they looked at, and they labeled the alanine and the histidine with a radioactive labeling, basically, so they could follow the intact carnosine from the digestive system, the bloodstream and, eventually, in the urine.

The thought is, if you give somebody this radioactive—that sounds bad, but it's safe. If you give somebody this radial labelled carnosine and they ingest it and then, eventually, down the line, maybe hours later or a day later, you find it in the urine, that means it went from the gut to the blood to the kidneys to the urine. If you find the radial labelled carnosine in the urine, that means it got through the digestive system intact. If you don't find any of this carnosine that's radial labelled and intact, then that means maybe carnosine doesn't survive the digestive tract. So, what they found in this study was that carnosine was, sure enough, found in the urine intact.

So, the peptidases—the enzymes that break down proteins—were not working on just dipeptides. Now, does that mean all dipeptides where you just have two amino acids stuck together? Does that mean all of them aren't broken down in the gut? No. No. At least, alanine and histidine aren't. When these two are connected together, the peptidases don't work on them and it does come through intact into your body. So, based on this, 1991 research did, in fact, show that carnosine as a supplement, it's not a gimmick. It does work. It does get into your system. I think that was a good question.

Now, the second question that R.F. has for me is about resveratrol.

R.F. asks, "I have resveratrol from Japanese knotweed. Now, I heard some supplement manufacturer emphasize that theirs is not from knotweed. Is this knotweed one inferior?"

No. Resveratrol is a compound found in nature. It falls under the class called "stilbenes". Stilbenes are found in all sorts of dietary sources and plant-based sources. I think classically, people know resveratrol—my dad knows it as the red wine supplement because we talk about the benefits of red wine, the resveratrol, the skin of the red grape and all that kind of stuff. I think that kind of sits in peoples' minds. But, resveratrol and other stilbenes are found in grains, leafy greens and other types of fruits. They're found throughout the plant kingdom, these stilbene compounds. So, I don't know anything specific about Japanese knotweed as a source of resveratrol, but I have no reason to think that it's inferior. The most important thing is that it is the trans- form of resveratrol.

Resveratrol comes in two forms: cis- and trans-. It's the trans- form, trans-resveratrol, that probably has the influence on the anti-aging genes, the sirtuins genes. So, that, to me, is what's more important. The trans- form about 250mg, whether it's coming from the skin of red grape or knotweed, I don't think that that determines whether the resveratrol is better or not. So, trans-resveratrol, 250mg and if you're confident. R.F., just for a moment, forget the knotweed issue. Just look at the final product. Look on the back label. If it says, "trans-resveratrol, 250mg", if you're confident in this company, if you're confident in the label, then it should be just fine.

Now, how do you become confident in the label. Well, I would, personally, call the manufacturer. There should be a manufacturing number on the back of the label. I would call them up and I would ask them for a Certificate of Analysis. I've talked about the C of A's, Certificate of Analysis, on my show. It's a document proof of a label. As a matter of fact, some companies even have a C of A for the raw material—the knotweed—that it is really knotweed and then, they have a C of A for the final product. So, call the manufacturer. Ask them for a Certificate of Analysis. So, look on the back label. Does it say "trans-resveratrol"? Does it say "250mg"? Because that's where the dose should be. Okay. That's good. Now, you want to make sure that label is correct, so you call the manufacturer and you ask for a Certificate of Analysis.

If the person on the other line of this company where you're buying it from, if they have no idea what you're talking about, then you might want to find a different trans-resveratrol. If they do have a Certificate of Analysis, as long as you know that they have it, but if you want even further...If you want to feel better even more, you could ask them to send you the Certificate of Analysis. I know at Life Extension, where I work, we can email it. We'll fax it. We'll do whatever if people want it.

So, again, I don't think it's the source that's so important. I think it's the quality of the resveratrol in the final product which should be in the trans- form, 250mg and as long as you have confidence in that product, that label, then you should be okay.

Great questions.I think I've got a minute or so left, so I'll do a quick one.

"How do I ascertain if a supplement will adversely impact my pharmaceutical medications?"

Well, you know, the only way...Well, first of all, the good news is, there are very few dangerous interactions between supplements and drugs. There are a few out there, but there are very few. That's the good news. But if you really want to know, probably one of the best websites for that is That's the site I use. It's the site health advisors at Life Extension use.

If you call them up and you have questions about a drug and a supplement, they go to You just plop in what you're looking at, what you're taking, what you want to use and they'll tell you if there are any interactions. Really simple. Alright. This is Healthy Talk on RadioMD. I'm Dr. Mike. Stay well.