Welcome to the Yestimun® FAQ page. This is where we deal with the most frequently asked questions concerning our Brewers’ Yeast beta-glucan and help you to find out more about the benefits and correct use of the product. If you have any further questions, feel free to put them to us at our contact form.
End customer (consumer) FAQs:
Immune health is so important because it concerns our body’s immune system, which protects us against infections, diseases and other harmful intruders. A strong immune system helps the body to ward off bacteria, viruses, fungi and parasites that cause illnesses or to heal faster if they have already entered the body.
If our immune health is impaired, our body is more susceptible to infections and diseases, which can lead to an increased risk of chronic diseases such as cancer, diabetes and cardiovascular diseases, for instance. A weak immune response can also foster autoimmune diseases and allergies.
Good immune health also includes a balanced diet, sufficient sleep, regular exercise and stress management as well as the avoidance of harmful modes of behaviour such as smoking and alcohol consumption.
A healthy lifestyle enables us to strengthen our immune system and reduce the risk of diseases and infections.

Yestimun® Beta-Glucan is a light beige, fine, tasteless and odour-free powder. . It has a highly immunosupportive effect that has been proved in clinical studies and is already used in a variety of functional foods, beverages and supplements. Yestimun® additionally offers benefits thanks to the following properties:
– Can be taken daily
– No known side effects
– Efficacy proved by studies
– Kosher and halal-certified, non-allergenic and GMO-free
– Suitable for vegetarians and vegans
Yestimun® stimulates the immune cells in the intestine to trigger a non-specific or also a specific immune response that activates the so-called scavenger cells (macrophages) in the Peyer’s patches. These scavenger cells begin with the destruction of pathogens and activate further defence cells such as B- and T-cells or dendritic cells, for instance Yestimun® therefore strengthens the immune system and prepares it so that it can respond quickly in the event of an infection.
By supporting the white blood cells, Yestimun® contributes extensively to combating bacteria, viruses, fungi and parasites that cause illnesses.
Yestimun® is a natural product that is sustainably obtained from upcycling high-quality Brewers’ Yeasts (Saccharomyces cerevisiae).
One major difference between Yestimun® and other immune ingredients (such as vitamins, minerals, etc.) is its ability to modulate the immune system. Yestimun® strengthens the body’s defences and at the same time enables it to work in an efficient and balanced way. Overall, Yestimun® is a unique ingredient that plays a special role in strengthening the immune system due to its ability to immunomodulate and improve the immune response to pathogens.
Another important difference between Yestimun® and other immune ingredients is its ability to improve the immune response to various pathogens. Studies have shown that Yestimun® increases the production of certain antibodies that specifically target bacteria and viruses. This makes Yestimun® a particularly effective immune ingredient in fighting infections.
All in all, Yestimun® is a unique immune ingredient that plays a special role in strengthening the immune system thanks to its ability to modulate it and to improve the immune response to pathogens.

Taking Yestimun®.
Yestimun® can be taken flexibly at any time of day, regardless of meals. However, for optimum effect, regular intake is recommended – ideally at fixed times. It is taken orally, depending on the dosage form.

The effect of Yestimun® on the body is universal and encompasses a variety of functions from allergies and autoimmune diseases up to and including the modulation of the immune system.
Yestimun® supports the physical performance of athletes and fosters regeneration after training. It supports:
- The immune system and therefore reduces susceptibility to infections. This is particularly important for athletes, who may possibly be exposed to an increased risk of infection due to their intensive training.
- Regeneration: by reducing inflammations and oxidative damage in the body, Yestimun® can help to minimise aching muscles and injuries and speed up recovery.
- Physical performance: Yestimun® can improve physical performance by helping to optimise energy production in the body. This can help athletes to enhance their performance and train at a high level for longer.

The product was already classified as safe by external bodies before the clinical trials were carried out. It can be taken daily and there are no known side effects.
Yes, Yestimun® is suitable for vegetarian, ovo-lacto vegetarian and vegan diets.
Yestimun® contains no allergens pursuant to EU Directive No. 1169/2011.
Yes. Leiber does not process any products containing GMOs and is also certified accordingly.
Manufacturer FAQs:
Yestimun® is a natural beta-1,3/1,6-glucan that is obtained from the cell wall of Brewers’ Yeast (Saccharomyces cerevisiae). The fine, light beige, spray-dried, tasteless and odour-free powder is dispersible and can be easily used in diverse dry or even liquid product formulations. Leiber Brewers’ Yeast beta-glucan is characterised by its very high level of purity and its unique molecular structure. Its immunosupportive effectiveness has been demonstrated on the basis of clinical studies.
Brewers’ Yeast beta-1,3/1,6-glucan has the following properties:
- Can be taken daily
- Without known side effects
- Efficacy proved by studies
- Kosher-certified
- Halal-certified
- Non-allergenic (EU 11/69 2011)
- GMO-free
- Suitable for vegetarians and vegans
- Already used in hundreds of products worldwide
- Novel food Approval in Europe
- GRAS status (USA)
In which end products can Yestimun® be used?
The fine, light Yestimun® Beta-Glucan powder is tasteless and odour-free. For that reason, the dispersible ingredient can easily be used in a wide range of dry or even liquid product formulations. Because of this, the dispersible ingredient can be easily used in diverse dry or even liquid product formulations. Its application areas extend from food & beverages to sport & nutritional supplements.

Pursuant to its European novel food status, Yestimun®’s declaration is ‘Beta-glucans from yeast (Saccharomyces cerevisiae)’. However, the declaration can vary depending on the country.
Yestimun® is a natural product. In contrast to other immune ingredients:
- – It is obtained sustainably from upcycling high-quality Brewers’ Yeasts (Saccharomyces cerevisiae)
- It is produced in Germany
- It modulates the immune system and therefore not only strengthens it, but also enables it to function in a more efficient and balanced manner
- It has a very high level of purity that verifiably contributes to its better and more effective action
- It is already a globally known brand and is used in diverse product formulations
The recommended daily intake for adults and children aged 12 and over is 250mg Yestimun®. According to Novel Food Regulation (EU) 2017/2078, up to 1,275mg of yeast beta-glucan can be consumed without hesitation.
Quality and safety.
Yestimun® is available in powder form. It is dispersible and can be easily used in diverse dry or even liquid product formulations.
Yestimun® is a Leiber GmbH product and is produced in Germany.

Leiber uses the current Megazyme method to measure the β-1,3-1,6-D-glucan content of Yestimun®. The enzymatic method is designated in the FCC (Food Chemical Codex) as the official method for quantifying yeast beta-glucans. The Megazyme test kit involves a validated method.
Yes, Yestimun® is stable. The dry powder has a minimum shelf life of five years from the production date if stored appropriately.
Yestimun® Beta-Glucan is safe. The product’s safety has been proven in clinical efficacy studies. It can be taken daily and has no known side effects.
Precise microbiological, physical and chemical inspections of the incoming raw materials are firmly established at Leiber. Only this procedure enables the targeted selection of raw materials for the demanding Yestimun®. Top quality is our standard, something that we at Leiber guarantee.
Efficacy.
Yestimun® stimulates the immune cells in the intestine to trigger a non-specific or also a specific immune response that activates the so-called scavenger cells (macrophages) in the Peyer’s patches. These scavenger cells begin with the destruction of pathogens and activate further defence cells such as B- and T-cells or dendritic cells, for instance Yestimun® therefore strengthens the immune system and prepares it so that it can respond quickly in the event of an infection.
By supporting the white blood cells, Yestimun® contributes extensively to combating bacteria, viruses, fungi and parasites that cause illnesses.
The effect of Yestimun® on the body is universal and encompasses a wide variety of functions from allergies and autoimmune diseases up to and including the modulation of the immune system.
Yes, its effect has been proved through numerous studies