Glucosamine: characteristics, indications and contraindications that you do not expect

Glucosamina immagine in evidenza

In short.

In detail we will talk about

A complete resource on glucosamine, its benefits and contraindications. For which problems it is indicated and what is the exact daily dosage.

Fundamental element for the health of the cartilage and bone system, we go to deepen the scientific and practical knowledge on glucosamine. Let’s learn more about its characteristics, explaining what it is and what it can be useful for. Let’s explore the topic further with all the indications on where to find it in nature and how it is used for food supplementation .

Later we will learn to recognize, beyond the use made of glucosamine as a supplement, which foods are richer in it. Another fundamental topic: the indications on the use of glucosamine. Specifying the cases and people for whom it is recommended to use it.

In the final part of the resource we will analyze the importance of respecting the recommended daily doses. We will also underline the scientifically reliable sources that certify its quality and problems in daily use . The last paragraph will be entirely dedicated to the answers to the most important questions relating to the characteristics and use of glucosamine and more.

What is glucosamine, what is it used for?

Let’s get to know glucosamine by describing its details and characteristics. Starting by saying that this is a sugar that has the function of synthesizing many natural substances . Among these substances there are also some fats such as lipids , proteins and sugars themselves.

There are several reasons why taking glucosamine can be useful. This has a strengthening function for the joints . Its main function is to act on the cartilages by delaying their wear . With the intake of adequate amounts of glucosamine it is possible to better preserve the elasticity of the joints .

Since it is one of the fundamental components of the cartilage found in the joints, it is essential to maintain adequate levels of this for the health of the tissue. This will help avoid friction and friction between the bone ends due to a malfunction or excessive wear of the cartilage.

Referring to the fact that this is fundamental in other essential elements of cartilage, glucosamine levels must be adequate for the balanced production of proteoglycans, glycosaminoglycans and GAGs.

This elastic efficiency function is also possible thanks to the “lubrication” capacity guaranteed by the presence of the synovial fluid . Glucosamine is also present within this . Therefore, an adequate level of this molecule is essential also in the synovial fluid.

How many types of glucosamine are there?

Three different types of glucosamine have been identified in nature. Each of these has a specific function that distinguishes them from the other. These three types are:

  • Glucosamine hydrochloride (hydrochloride);
  • N-acetylglucosamine;
  • Glucosamine sulfate.

Glucosamine hydrochloride, what is it for?

Glucosamine hydrochloride is an indispensable molecule for maintaining elasticity and functioning of the cartilage structures of the joints. This seems to have not only nutritional capacity for the cartilage tissues, but also a high anti-inflammatory influence for the tissues themselves.

The latter factor seems more related to the ability of glucosamine to affect mediating elements of inflammation . This, in fact, appears to be able to inhibit the action of nitric oxide and an enzyme known as COX-2.

What is N-Acetylglucosamine?

Also known as N-acetylglucosamine or as N-acetyl-D-glucosamine. Like glucosamine hydrochloride and glucosamine sulfate, it is a derivative of glucosamine.

Unlike these two, however, N-acetylglucosamine is also responsible for the production of hyaluronic acid . This is possible thanks to the combination of N-acetylglucosamine molecules, precisely, with those of glucuronic acid.

Glucosamine sulfate, what is it and what is it used for?

Like glucosamine hydrochloride, glucosamine sulfate maintains the levels of elasticity and efficiency of the cartilage structures. There are no substantial differences between these molecules.

They are both able to improve the resistance of these tissues and the lubrication of the affected areas to avoid bone friction. To differentiate them is only the anion that allows the absorption of the two molecules.

Where is glucosamine found in nature?

It is not possible in any way to include glucosamine in a specific diet , because it is not found in any food . In nature, glucosamine is only found in the animal world.

This molecule, therefore, must be synthesized and used as a supplement to a dietary regimen. The main components of the cartilage tissues of the joints are glucosamine and chondroitin. Like the first, chondroitin is also detectable only in some animals.

Glucosamine and chondroitrin, where are they found in nature?

Where can glucosamine and chondroitin be found in nature? The first element is massively present in the structure of the shellfish carapace. The main crustaceans that possess considerable quantities of this molecule are:

  • Shrimp;
  • Lobsters
  • Crabs.

These, however, lack considerable amounts of chondroitin . This molecule, in fact, is available in animals such as :

  • Stingray;
  • Sharks.

These are molecules with different characteristics. The latter, in fact, can be found in the cartilage tissues of rays and sharks, specifically in areas such as the trachea .

Glucosamine indications: who is it recommended for?

What are the main applications of glucosamine in the treatment of diseases and health problems? Being molecules often found in cartilage and bone structures, they are indicated for the following health problems:

  • Osteoarthritis;
  • Rheumatoid arthritis.

Glucosamine sulfate against osteoarthritis, does it really work?

More in-depth studies are still underway on some of the effects that this molecule can have on the joints. Many studies have already demonstrated the absolute effectiveness of glucosamine sulfate in people suffering from knee osteoarthritis . One of the main effects of taking glucosamine is the noticeable decrease in knee pain .

Many other researches have also highlighted the effectiveness of the molecule against the degeneration of cartilage structures due to osteoarthritis . As noted earlier, much research is still ongoing on the benefits of glucosamine.

Some of these studies have as their object the efficacy of glucosamine sulfate for the treatment of osteoarthritis of the hand, hip and spine.

Glucosamine hydrochloride against rheumatoid arthritis

Regarding the efficacy of glucosamine hydrochloride against rheumatoid arthritis , a number of studies are still ongoing. Many researches carried out have shown a certain effectiveness against rheumatoid arthritis pain .

This is the only effect recorded so far, because no other significant effects were found in the same studies. For example, many of these focused on using glucosamine hydrochloride against joint inflammation and swelling . In this case, no particular positive effects were highlighted .

Glucosamine: when to take it?

Regarding glucosamine, it is possible to underline that the development of an analgesic effect is quite immediate from the moment we start taking the supplement. The long-term benefits are evident after prolonged treatments of about 60 days with a daily intake .

Clinical research has shown the lack of toxicity in taking the supplement. This means that prolonged courses of glucosamine can be well tolerated. Within 60 days, the first positive effects, given by the intake of glucosamine, on the cartilage structures begin to be seen.

There are no major differences whether you choose to take glucosamine sulfate, glucosamine hydrochloride or N-acetylglucosamine. There are, however, “yield” percentages of supplements currently available on the market. Let’s see a list of these supplements and their yield:

  • Glucosamine sulfate: 65% yield of glucosamine;
  • Glucosamine hydrochloride: 83% yield of glucosamine;
  • N-acetylglucosamine: 75% yield of glucosamine.

Let’s now take a closer look at the information regarding glucosamine dosage.

What is the right daily amount of glucosamine to take?

How Much Glucosamine Should You Take Each Day? Regardless of the type of glucosamine present in the supplement, this generally must not exceed the quantity of 1500 mg recommended daily. As we will see later, particular cases must be excluded from this clarification.

Can glucosamine sulfate be taken in a single dose? Like the other types, glucosamine can also be taken in a single daily dose. However, the most popular route for glucosamine dosing at present is at least 3 doses per day.

What changes between the three types of molecule as regards the intake? The most useful example, in this regard, is that relating to glucosamine hydrochloride which, in the form of a powder for integration, can include different types of salts in the composition.

Should the person’s weight be considered in the glucosamine dosage? Absolutely yes, even if this type of attention should be paid above all to obese patients. Let’s consider a subject weighing more than 90 kg. He should take more daily for adequate supplementation. A consultation with your GP is therefore essential to have a clear indication on the dosages.

In patients weighing more than 45 kg the daily dosage should not exceed 1500 mg . The doses for people weighing less than 45 kg change. For these subjects it is advisable not to exceed 1000 milligrams per day of glucosamine.

Daily Glucosamine Dosage: Some Things to Know

The indications given above regarding the daily dosage may also undergo variations when it is your doctor to suggest them. There are situations , in fact, for which it is essential to increase the dosage , while it is necessary to consider cases, on the other hand, for which it is essential to better control the daily intake.

Some of these cases are those related to patients who are already taking another drug or who are treating conditions of general osteoarthritis or osteoarthritis of the knee.

Treatments for knee osteoarthritis may require a different amount of glucosamine per day. Generally we are around 300 mg per dose (3 times a day) for less severe cases . It is possible to recommend taking up to 500 mg per dose (always in 3 daily solutions) in cases considered by the doctor to be more serious.

Real treatments, on the other hand, may be required for cases of general osteoarthritis , with dosages even higher than 2000 mg per day . These treatments usually have a well-defined time frame. For example, it is often recommended to follow this therapy for up to 18 months .

Glucosamine before or after meals?

Is it better to take glucosamine on an empty stomach? The division into two or three daily doses is designed to be managed during meal times. This type of supplement is generally taken immediately after meals in the recommended dosages.

Therefore, 1500 mg immediately after a meal, or 500 mg after the main meals of the day (breakfast, lunch and dinner) .

All those who are taking these supplements in one go often have doubts about the best time to take it. In the middle of the day, therefore after lunch, it is certainly the most suitable time, that is, immediately after having had an important meal with adequate caloric support.

This choice is also to be attributed to the problems that these supplements can bring in subjects prone to nausea or heartburn. These are effects that can be accentuated precisely as a consequence of the intake of glucosamine. To mitigate them, therefore, it is always advisable to take it after a meal.

Glucosamine contraindications: here’s when to avoid taking it

Are there cases in which it is not recommended or highly not recommended to take supplements of this type to avoid experiencing side effects? Glucosamine-based supplements are highly safe, however, there are conditions or therapeutic situations for which it is best to avoid taking this molecule.

Glucosamine and diabetes

There is very recent research available which shows that there is no correlation between the intake of glucosamine sulfate and the onset of problems in diabetic patients . These studies are a direct response to some previous research that had highlighted the presence of some doubts about it.

Concerning the incidence of glucosamine sulphate in diabetic patients, the question was whether this contributed to a significant increase in glycemic levels. The increase in these levels could result in an increase in the difficulty of synthesis of hexosamine.

Glucosamine and asthma

Having asthma and taking glucosamine may not mean having directly related side effects. The reference is to research that would have made it possible to identify some link between the intake of the molecule and the asthma attacks.

At the conclusion of this research, however, it is still unclear whether the true trigger can actually be attributed to glucosamine.

Glucosamine and anticoagulants

Some research has shown a certain relationship between the consumption of glucosamine hydrochloride and anticoagulant medicines in relation to some side effects. In fact, it seems that the concomitant intake of these two products leads to further slowing down the coagulation process .

This could lead to immediate effects such as increased bruising and bleeding. A specific example is that relating to the consumption of glucosamine and warfarin as highlighted in this research:

Potential glucosamine-warfarin interaction resulting in increased international normalized ratio: case report and review of the literature and MedWatch database – PubMed (

On the sidelines of this condition, it should be considered that there are actually many drugs that interfere with warfarin-based therapies. This remains, therefore, an aspect to be researched in more depth in order to arrive at a valid answer.

Glucosamine and paracetamol

One of the latest evidences to be taken into consideration regarding glucosamine is the possibility that it interacts with paracetamol . In this case, subjects who take paracetamol and glucosamine may notice a decrease in the effectiveness of both .

Glucosamine: main side effects

Side effects directly linked to taking supplements based on this molecule are also to be considered. Mainly these are a series of minor conditions which can be:

  • Stomach ache;
  • Constipation;
  • Nausea;
  • Diarrhea.

We are faced with a series of conditions that can be considered classic with respect to the intake of glucosamine-based products. More rare conditions are also to be listed, but which can still occur and which correspond to:

  • Skin rush;
  • Heachache;
  • Drowsiness.

Another aspect to consider are the reactions in subjects allergic to fish products. Glucosamine is often extracted from animals such as crabs and shrimps and in people allergic to shellfish it can cause any allergic reactions.

Glucosamine FAQ

After reading our in-depth analysis, let’s summarize the most researched questions about this molecule and the supplements available on the market.

What is glucosamine good for?

The main role of glucosamine is to contribute to the integrity and functioning of the cartilage structures present in the extremities of the joints. The function of these structures is to cushion the ends of the bones and prevent friction and, therefore, chipping between them. The inefficiency of the cartilage structures present in the joints can lead to painful consequences in movements, especially in those who play sports.

What foods is glucosamine found in?

Although widely found in nature, glucosamine is not found in any food. The most practical way to take this molecule is to rely on the supplements on the market and available in both powder and tablet form.

What are glucosamine and chondroitin used for?

These two elements in combination can have an even higher efficacy on cartilage health. In addition to the normal action attributed to glucosamine supplements, the action of chondroitin sulfate also appears to be effective for the treatment of other conditions, such as slowing down the wear and tear of cartilage and having an anti-inflammatory effect on it.

What are the daily dosages of conroitin?

Daily dosages of chondroitin are generally lower than those for glucosamine. We refer to a person weighing more than 45 kg. For subjects with these characteristics it is better not to exceed 1200 mg per day. Individuals weighing less than 45 kg, on the other hand, should take a maximum of 800 mg of chondroitin sulfate.

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