Oyster Mushroom

(Pleurotus Ostreatus)

Evidence: High
Possible Benefits: Very High
Safety: High

TABLE OF CONTENTS

What is the oyster mushroom?

Pleurotus ostreatus, also known as the oyster mushroom, is a type of mushroom with a long history of use as a traditional medicine in many places around the world. This mushroom is often used as a supplement for improving heart health and immune function. This article is about the main benefits of Pleurotus ostreatus, its potential side effects, the best time to take it, and more.

Possible benefits

All of the potential benefits mentioned below are dose-dependent. As with other adaptogenic mushrooms, there is a sweet-spot dose that allows you to get most of the benefits without causing meaningful side effects or tolerance buildup in the body. We will discuss the best dosing protocol later in this article.

Major benefits

  • Improved cholesterol levels – In multiple studies, 30 grams of dry oyster mushroom daily for 21 days was able to improve cholesterol levels by lowering LDL cholesterol and increasing HDL cholesterol. Keep in mind that this benefit may and may not apply to extracts and other oyster mushroom supplements.
  • Improved blood sugar levels – 150 grams of cooked oyster mushrooms for 7 days reduced fasting blood sugar by 22% and post-meal blood sugar by an average of 23%. More studies are needed to show if this benefit applies to extracts and other oyster mushroom supplements.

Minor benefits

  • Improved immune system – While more human studies are needed to determine whether or not this mushroom can improve immune health, mushrooms in general tend to positively impact immunity in most people, mainly because of their high beta-glucan content.
  • Anti-cancer properties – Polysaccharides in this mushroom may inhibit tumor cell proliferation and induce tumor cell apoptosis. Whether or not taking the mushroom as a supplement can protect a person from cancer and slow down tumor growth in humans is yet to be determined but the research we have available shows promise.

Possible side effects

The side effects below are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.

  • Nausea – This side effect is most common when people take the mushroom on an empty stomach.
  • Diarrhea – Just like nausea, diarrhea caused by the supplement can usually be prevented by taking the mushroom with food.
  • Toxicity – As an adaptogenic mushroom, Pleurotus ostreatus acts as a mild stressor on the body. That is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, stressing the body too much can be counter-productive and cause multiple side effects, including toxicity. While acute toxicity is extremely rare, taking high amounts of this mushroom could lead to chronic toxicity and cause some health problems over time. To prevent chronic toxicity or the buildup of tolerance, it is best to stay below 300 grams of whole mushrooms or 5 grams of extracts a day unless you have a great reason to take more.
  • Contamination – If growing conditions are not properly controlled, the oyster mushroom can be contaminated with bacteria, molds, and other potentially harmful microorganisms. The mushroom can also be contaminated because of poor harvesting, processing, and packaging practices. Some growers also use fungicides, chemical compounds designed to kill or prevent the growth of other fungi. Many fungicides can have detrimental effects on human health. Choose the brand you get mushrooms and mushroom supplements from wisely.

Who should not take oyster mushrooms?

You should probably avoid taking the mushroom if you:

  • are allergic to the oyster mushroom or mushrooms in general
  • experience a severe adverse reaction after taking the mushroom
  • are pregnant or breastfeeding (while it may be safe to take the adaptogen during pregnancy or breastfeeding, it can act as a stressor and should likely be avoided during this period)
  • suffer from an autoimmune disease (adaptogenic mushrooms can stimulate the immune system, which can worsen symptoms of autoimmune diseases, such as lupus or multiple sclerosis)
  • have liver disease (this mushroom might make the symptoms of the liver disease worse)

Who will benefit the most?

You should consider taking the supplement if you:

  • suffer from type 2 diabetes
  • experience high levels of inflammation
  • don’t suffer from any autoimmune disease but wish to improve immune health
  • have a high budget for supplements and are willing to experiment with a variety of them (Pleurotus ostreatus appears safe and is unlikely to do more harm than good in most people)

How much should you take?

Because Pleurotus ostreatus can be considered an adaptogenic mushroom, it acts as a mild hormetic stressor on the body, which allows your body to adapt and become more resilient in the long term.

As with other adaptogens, a higher dose does not necessarily lead to bigger benefits. Instead, there appears to be an inverted U-shaped dose-response pattern. In other words, you want to find a sweet-spot dose that allows you to get the benefits of the oyster mushroom without putting too much stress on the body or quickly causing the body to develop tolerance to the mushroom.

The sweet-spot dose typically ranges anywhere between 500-2000 mg of mushroom extract daily, which can be obtained from about 100 grams of the whole mushroom. This amount should provide most of the benefits without meaningful side effects.

The higher end of this range usually provides slightly more benefits in the short term. If you plan to take the mushroom for a longer time (multiple months or years), the lower end is probably a better way to go since you’d develop tolerance faster if you were to take higher doses.

While higher doses are generally safe, taking more than the sweet-spot dose daily would be counter-productive as your body would develop tolerance rather quickly. Additionally, very high doses can put too much stress on your system and cause some health problems if you take the supplement for a prolonged period.

Just like with most other adaptogens, it is best to cycle the oyster mushroom and stay off of it for about 2 days per week to reset your tolerance. This will allow you to keep getting the benefits in the long term.

Keep in mind that the effects of this mushroom are cumulative. Therefore, you must take it for at least 2-4 weeks to notice the benefits. But again, cycling the mushroom and not taking it at least twice a week is necessary to prevent tolerance in the long term.

Best time to take the oyster mushroom

The main bioactive compounds in Pleurotus ostreatus are fat-soluble so to maximize the absorption, take this mushroom with a meal.

Whether you take this mushroom in the morning or the evening doesn’t make much of a difference. Both options are fine.

Where to buy the oyster mushroom?

Amazon is the best option for ordering oyster mushroom and other mushroom supplements in most countries. They offer some very affordable products backed by many positive reviews. Also, you can choose from a wide range of brands without having to search through other markets on the internet.

Some brands display the dosage per serving instead of per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.

FAQ

As with most other mushrooms and mushroom supplements, it is best to cycle Pleurotus ostreatus and stay off of it for about 2 days per week to reset your tolerance back to baseline. This will keep your body sensitive to the mushroom and allow you to keep getting the benefits in the long term.

Yes, you can. This mushroom should not impact your sleep in any negative way. Whether you take it in the morning or the evening doesn’t make much of a difference. Either way, take the mushroom with food to maximize the absorption of its fat-soluble components.

This mushroom should not become harmful once it exceeds the expiration date but it can lose potency over time.

Keep the supplement in a cold, dark, and dry place, and it should remain just as potent for many months or even years.

As an adaptogen, Pleurotus ostreatus acts as a mild stressor on the body. This is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, putting too much stress on the body can be counter-productive and cause multiple side effects, including toxicity. While acute toxicity is extremely rare, taking high amounts of this mushroom could lead to chronic toxicity and cause some health problems over time. To prevent chronic toxicity or the buildup of tolerance, it is best to stay below 300 grams of the whole mushroom or 5 grams of an extract a day unless you have a great reason to take more.

This mushroom consists of many bioactive compounds, each of which has a different half-life in the body. Some of these components should be fully metabolized within hours while some of them will stay in the body for a few days.

The effects of this mushroom are cumulative. Therefore, you must take it for at least 2-4 weeks to notice the benefits. But again, cycling the mushroom and not taking it at least twice a week is necessary to prevent tolerance in the long term.

Yes, the oyster mushroom is vegan-friendly. If you buy the mushroom in a capsulated form, beware that the capsules often contain animal-based gelatin. Instead, find a brand that puts its products into cellulose capsules.

The oyster mushroom should not break a fast unless you take a very high dose at once. If you practice time-restricted eating, take this mushroom during your eating window so it doesn’t break your fast.

References

Most of the information provided in this guide is supported by scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything said in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.

You may also like:

We hope this guide has helped you determine if you should add the oyster mushroom to your supplement stack and how to do it right.

If you have any further questions or want to share your feedback, feel free to email us!

We may receive commissions for purchases made through the links in this post.

<- View All Supplements

Share this with your friends:
SuppleWiki