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Where are Functional Mushrooms Grown?

A rural landscape showing black plastic sheeting where mushrooms are grown in the foreground, with terraced fields and tree-covered hills in the background under a cloudy sky.
Written by Skye Chilton - Updated: June 28, 2024

Did you know that China grows over 94% of mushrooms worldwide?

Many of our customers ask us why we source all our mushrooms from China.

The answer is simple.

It is not possible to produce organic mushroom extract powders in North America.

While it is possible to grow these mushrooms in North America for food, you'll discover that it is too expensive to grow them at scale for supplement use.

U.S. Growing Economics

To demonstrate this, I will use shiitake mushrooms as an example, since they are one of the most inexpensive mushrooms to grow.

The 2019-2022 USDA average price for fresh non-organic shiitake mushrooms was $3.50 per pound. This equates to $7.70 per kilo.

So a U.S. grower receives $7.70 per kilo for fresh non-organic shiitake mushrooms.

Dried mushrooms are used for supplements so I will need to convert the fresh price to a dried price.

Mushrooms are generally around 90% water so when shiitake mushrooms are dried they will yield ~10% of the initial weight.

This means that for the grower to get the equivalent $7.70 per kilo fresh they will need to charge $77 per kilo dried. (1kg fresh = 100g dried. 100g * $77/dried kg = $7.70)

This is where the economics start to break down.

To produce a simple extract, the dried mushrooms must be ground into a powder, extracted with hot water and/or alcohol, concentrated and then converted from a liquid into the final extract powder.  Then, testing and quality control would be required to ensure the ingredient is safe for consumption. This can easily add upwards of $50 per kilo in equipment and labor.

$127 per kilo for a 1:1 shiitake mushroom extract powder with no additional profit margins added into the price yet. This is already too expensive for the majority of supplement companies.

And this is for non-organic and one of the cheapest functional mushrooms.

Certified organic mushrooms are more expensive and harder-to-grow mushrooms like reishi can easily double the price.

Now for an 8:1 extract like in our Turkey Tail product, 8 times the mushrooms are needed before processing even begins, so the raw ingredients costs would be $616+ per kilo. This would not be competitive in the current functional mushroom supplement marketplace which is why you cannot find it.

A 16:1 reishi dual extract like in our 5 Defenders Organic Mushroom Blend, would be over $1200 per kilo in dried mushrooms if grown in North America.

This is why mushrooms are not grown for supplements in North America.

organic reishi mushrooms
Inside of a reishi mushroom shade house.

What the USDA Says

If this is hard to believe, here's what the USDA says.

The U.S. Department of Agriculture releases reports every year on the production and sales of various agricultural crops; mushrooms being one of them.

They break it down into different categories like location, mushroom type, organic, etc.

Some interesting facts from their 2019-2022:

  • The U.S. grew 700 million pounds of mushrooms in 2021/2022(<3% of worldwide production).
  • The button mushroom (Agaricus bisporus) accounts for 97% of this.
  • Specialty mushrooms (non-button mushroom) account for the other 3%.
  • Organic mushrooms are 22% of production with 82% of this being the button mushroom.

Now if we want to consider functional mushrooms, we need to look at specialty mushrooms. Specialty mushrooms are broken into shiitake, oyster and other. The table below breaks down the total production for 2021/2022:

A table showing specialty mushroom total production, sales, price, and value in the United States from 2019 to 2022, categorized by variety including Shiitake, Oyster, and other grown functional mushrooms.
Specialty mushroom estimates represent growers who have at least 200 natural wood logs in production or some commercial indoor growing area, and $200 in sales.

While the U.S. grew 23 million pounds of specialty mushrooms, footnote #3 says: "Virtually all specialty mushrooms sales are for fresh market"

The USDA is saying that there is basically no specially mushrooms being grown that are being used by anything other than the fresh market (ie. None of these mushrooms are being used for supplements).

This confirms the statements above about it being too expensive to grow functional mushrooms for use in supplements in the U.S. or North America for that matter.

The Alternative to Mushrooms

Mycelium growing on a grain-substrate
A solid mass of myceliated grain, or mycelium biomass, shown as a fully grown block, but when breaking apart, revealing it to be mostly grain.

But you can find so-called functional "mushroom" supplements claiming to be U.S. grown.

Functional mushroom supplements and ingredients that are claiming things like "US Grown" almost always do not contain any mushrooms. As you've seen above, it is too expensive.

But if it's too expensive to grow them then what is it?

The main suppliers of U.S Grown "mushroom" ingredients are actually selling myceliated grain and not mushrooms. If you're a mushroom grower, you will recognize this product as grain spawn. It is the seed used to start the process of growing mushrooms.

Myceliated grain is sterilized grain that has been inoculated with the mycelium of a fungal species like shiitake, reishi, lion's mane, turkey tail etc. The shiitake mycelium will then begin to grow out on the grain and in 30-60 days it will be dried, powdered and sold as a "mushroom" ingredient grain and all even though it contains no mushrooms.

It is very cheap to produce and hence economical for use in supplements.

Here's an example of the full process from start to finish and you can read further on how to identify myceliated grain.

Who Grows all the Mushrooms?

China is the leading grower of mushrooms worldwide, accounting for over 94% of production as of 2022 (2). Their mushroom production has increased around 40 times in the last 30 years. China is now commercially cultivating more than 60 different mushroom species.

Line graph showing the yield of mushrooms in China from 1990 to 2020, illustrating how functional mushrooms have grown from about 1 million tons in 1990 to nearly 40 million tons in 2020.
The dramatic increase in mushroom cultivation volumes in China over the last 15 years are clear in this graph.


Cultivated mushroom production in China and selected regions of the world, 2013 (billion kg)
Cultivated mushroom production in China and selected regions of the world, 2013 (billion kg)


Shiitake (lentinula), Wood ear (auricularia) and Oyster (pleurotus) mushroom have all pushed ahead of the button mushroom (agaricus) in global production.


World edible mushroom production (% of total) by genus (2013)
World edible mushroom production (% of total) by genus (2013)


Cultivation Practices of Mushrooms in China

China has a rich history around mushrooms. They have been a food source and used in traditional Chinese medicine for hundreds, if not thousands, of years. China was the first to begin cultivation of mushrooms in the early 13th century. They have more researchers than anywhere else in the world and have many research centers dedicated solely to the development of mushrooms: whether it's as food or as medicine.

China has only recently increased their consumption of mushrooms. As production has increased so has consumption. In 2005, per capita consumption was only 0.5kg per year. In 2021, it is now 63.82kg. For comparison, Americans eat roughly 1.36kg of mushrooms per year; around 47 times less than China. A Chinese person will eat more mushrooms in less than 2 weeks than an American will eat in a year. 

Mushroom growing is a very big business in China. It is now a top 5 agricultural crop for them behind grain, vegetables, fruit, and edible oil plantations. It is greater than sugar, cotton, and tobacco production. China is now using mushroom production to help local communities out of poverty where mushroom growers earn 10 times more than rice or corn. Li Yu, a noted mycologist and an academician of the Chinese Academy of Engineering has been a champion of using mushroom growing to alleviate poverty.

Every year when I travel to China during the mushroom harvest season and visit the organic mushroom farms, I eat so many different kinds of mushrooms. There is not a single meal that goes by where there is not some kind of mushroom dish.

Real Mushrooms team & mushroom growers
Skye and Jeff Chilton pictured alongside a couple of proud farmers at an organic reishi farm in China.

FAQs About Our Sourcing

1. How can you be sure that the mushrooms coming from China are not contaminated?

All of our mushroom extracts come from Nammex, the leaders in organic mushroom extracts. They supply some of the biggest companies in the world with mushroom ingredients.

All of our extracts are tested multiple for heavy metals, pesticides, and microorganisms. Once in China, again when it arrives in the US and a 3rd time after it goes in the finished packaging.

The “Consumer Reports” of supplements, ConsumerLab, has chosen Real Mushrooms as their top mushroom supplement for the last 3 years in a row. They are an authority in independent testing for supplement quality.

2. Why don’t you buy your mushrooms from independent mushroom farms in North America?

It's important to understand that while it is possible to grow mushrooms in North America for food, or very small scale DIY supplements or tinctures, economically speaking, it's too expensive to grow certified organic mushrooms for dry extract powders at scale. “At scale” is the key here. This is the entire reason why companies grow myceliated grain in the US, and sell them as mushrooms instead. US grown myceliated grain is a lot cheaper than organic mushroom extract powders from China.

3. What are the working conditions at the farms you source from?

The workers at the farms our supplier, Nammex, partners with, are treated very fairly and have a great quality of life. One of our missions is to bring awareness and educate consumers that not all products that come from China are inherently harmful, and rest assured that we would never support any farms that practice harmful treatment of their workers.


For medicinal mushrooms, China is the leading grower worldwide with no other countries coming close to their production volume. For this reason, if you want a mushroom extract that is actually made from the mushroom, it needs to come from China.

Growing mushrooms in North America is too expensive for supplement use. The only option is laboratory grown myceliated grain because it is much cheaper to produce. But myceliated grain is not mushrooms and should not be marketed as mushrooms when it does not contain any mushrooms and the majority of it is grain.

When selecting a functional mushroom product it is important that it is:

Assortment of mushrooms and packaged mushroom supplements displayed on a counter with a "Fall health tips" sign overlay.


  1. August 21, 2018, USDA, Mushroom Product and Sales
  2. Royse, D. J., Baars, J., & Tan, Q. (2017). Current Overview of Mushroom Production in the World. Edible and Medicinal Mushrooms, 2010, 5–13.
  3. Li, C., Xu, S. Edible mushroom industry in China: current state and perspectives. Appl Microbiol Biotechnol 106, 3949–3955 (2022).
Skye Chilton
Skye is the founder of Real Mushrooms. Read more about his story into medicinal mushrooms here. When he’s not spreading the word of Real Mushrooms, he enjoys mushroom foraging, bouldering, cooking, gardening and hiking.

Disclaimer: The information or products mentioned in this article are provided as information resources only, and are not to be used or relied on to diagnose, treat, cure, or prevent any disease. This information does not create any patient-doctor relationship, and should not be used as a substitute for professional diagnosis and treatment. The information is intended for health care professionals only. The statements made in this article have not been evaluated by the Food and Drug Administration. Any products mentioned are not intended to diagnose, treat, cure, or prevent any disease. The information in this article is intended for educational purposes. The information is not intended to replace medical advice offered by licensed medical physicians. Please consult your doctor or health practitioner for any medical advice.