Who Should Not Drink Mushroom Coffee?

So, who should not drink mushroom coffee?

For most healthy adults, mushroom coffee is probably safe, but some people should avoid it or take care. Avoid it if you have a mushroom allergy, are pregnant or breastfeeding, or take blood thinners or immunosuppressants. Avoid Chaga blends if you have kidney disease. Ask your doctor first if you have an autoimmune condition, low blood pressure or take any medication.

If none of that applies to you, mushroom coffee may be worth a try. I’ll show you how to start safely further down.

A few years ago, I stood in my kitchen, feeling pretty proud. I had just blended what I thought was the perfect cup of mushroom coffee.

I’d added speciality coffee beans, lion’s mane and milk; the whole works. I took that first sip and thought, this might just be magic.

I’m James Bellis, founder of Balance Coffee, a coffee entrepreneur and a biohacker. I have 14+ years in the coffee industry and hold an SCA Coffee Skills Diploma. I specialise in healthy coffee, biohacking and functional mushrooms, and my full bio is here.

For about three weeks, I drank it every morning and loved the taste.

So naturally, I wanted to share my mushroom coffee discovery with everyone.

I gave a bag to my friend Sarah, who always trusts my coffee tips. A few days later, she texted me: “I think your coffee hates me. My stomach’s in knots.”

I laughed at first. Then I realised that this was serious.

Feeling curious (and a little guilty), I called my nutritionist, Clementine Rose. We went through Sarah’s health history together. Sure enough, mushroom coffee wasn’t a good match for her sensitive stomach and autoimmune issues.

That moment taught me something important: not all “healthy” things are healthy for everyone.

So, if you’re thinking about mushroom coffee, this post is for you. I’m sharing exactly who should not drink mushroom coffee, based on real experiences and research.

But first, it helps to know what mushroom coffee actually does inside your body.

Understanding How Mushroom Coffee Affects the Body

When I began my mushroom coffee journey, these questions popped into my head:

• Is mushroom coffee safe for everyone?
• Who should avoid it altogether?
• Can you drink mushroom coffee daily?
• Does mushroom coffee give you energy?

How mushroom coffee affects you depends on the medicinal mushrooms it contains. These could be Chaga, Reishi, Cordyceps or Lion’s Mane.

Each one contains bioactive compounds. These are natural chemicals that may change how parts of your body work.

People drink it for many reasons, which we cover in our guide to mushroom coffee benefits.

Now the caveat.

Research on medicinal mushrooms is still early. Much of it comes from lab and animal studies, not large human trials.

So what inside the mushrooms is doing the work? Three groups of compounds come up most often.

Beta-glucans

Beta-glucans are a type of fibre found in mushroom cell walls. They are one of the main compounds researchers study in these mushrooms.

WebMD says beta-glucans can switch on white blood cells, the cells that fight germs. That same immune effect helps explain who should not drink mushroom coffee.

A 2017 study in mice suggests Lion’s Mane may switch on immune cells in the gut. It was published in the journal Food & Function.

But beta-glucans are only one part of the picture. Some mushrooms also carry compounds called triterpenes.

Triterpenes

Triterpenes are natural compounds found in some medicinal mushrooms.

A herbal medicine textbook chapter says Reishi contains triterpenes called ganoderic acids. These may play a part in how Reishi affects the immune system.

Cordyceps works in a different way. Its best-known compound isn’t a triterpene at all.

Cordycepin

Cordyceps mushrooms are rich in a compound called cordycepin. It is a nucleoside, a small molecule that looks a lot like one found in every cell.

A 2020 review in the journal Molecules looked at cordycepin. It found signs that it may calm swelling, affect the immune system and protect cells.

Most of that research was done in labs and on animals. Even so, it suggests these compounds may affect your immune system, blood sugar and blood flow. That is why mushroom coffee isn’t right for everyone.

So which people should think twice before drinking it?

Who Should Be Cautious or Avoid Mushroom Coffee?

Jumping on the mushroom coffee bandwagon might seem like a safe idea at first.

But if you’ve had health issues in the past, read this section first to be safe. This guide covers eight groups:

• People with mushroom allergies
• People with autoimmune disorders
• Pregnant and breastfeeding women
• People taking blood thinners or other regular medicines
• People with low blood pressure
• People with kidney problems
• People with sensitive stomachs
• People who are sensitive to caffeine

These are the people who should not drink mushroom coffee without advice first. Let’s start with the most obvious one.

People with Mushroom Allergies

Okay, so this one’s a no-brainer. If you have a mushroom allergy, your alarm bells should already be ringing.

Drinking mushroom coffee could trigger a reaction if you have a mushroom allergy. Mild symptoms may include:

• Skin rashes or itching
• Stomach discomfort or nausea

So, are there any serious risks? In rare cases, it may cause severe allergic reactions, such as:

• Difficulty breathing
• Dizziness or light-headedness
• A sudden drop in blood pressure

If you have any of these symptoms, get medical help straight away. If breathing becomes difficult, call emergency services.

If you notice any allergic reaction, mild or severe, stop drinking it and speak to a doctor.

Allergies are fairly easy to spot. Immune conditions are harder, because the risk comes from the immune effect itself.

Individuals with Autoimmune Disorders

Healthline reports test-tube studies showing Reishi can affect the genes in white blood cells. These cells are a key part of your immune system.

For most people, that may not be a problem. But in autoimmune conditions, the immune system already attacks the body’s own tissue. Examples include:

• Lupus
• Rheumatoid arthritis
• Multiple sclerosis

Why does that matter?

Revving up an immune system that is already too active could, in theory, make symptoms worse. Human research on this is very limited, so this advice is a precaution, not proof of harm.

So, is mushroom coffee good for you if you have an autoimmune disorder? It may not be, so speak to your doctor before trying it.

Pregnancy raises a different problem. Here, the issue is simply how little research exists.

Pregnant & Breastfeeding Women

Research on how functional mushrooms affect pregnant and breastfeeding women is very limited.

MSD Manuals says the safety of Reishi in pregnancy and breastfeeding “is not known”. It advises pregnant and breastfeeding women to avoid it.

Then there is the caffeine.

Caffeine matters here too. The NHS says you should not have more than 200mg of caffeine a day while pregnant.

Pregnancy is one of the clearest cases of who should not drink mushroom coffee. If you’re pregnant or breastfeeding, avoid it.

If you’re weighing up a specific brand, our Ryze Mushroom Coffee review covers that blend in more detail.

If you want a warm drink instead, there are better options, such as:

• Decaf coffee
• Herbal tea, up to four cups a day, avoiding liquorice root (NHS pregnancy advice)
• A warm mug of milk

These drinks can help you relax without the unknowns. Medicines are the next big area, and they affect far more people.

People Taking Blood Thinners or Medications

One of the less obvious risks of mushroom coffee is how it may mix with medicines.

A 2006 study in the journal Peptides found a Chaga compound that slowed platelet clumping. Platelets are blood cells that clump together to form clots. The researchers also tested the compound in mice.

Let’s break that down:

Some medicinal mushrooms may also affect blood sugar and the immune system. Those effects can clash with certain medicines, such as:

Blood Thinners

Mushroom coffee may raise the risk of bruising or bleeding if you take blood thinners such as warfarin. MSD Manuals says taking Reishi with these drugs “might increase the chance of bleeding and bruises”.

The same source says people having surgery should avoid Reishi. On mushroom coffee and blood thinners, the safest answer is to avoid it unless your doctor agrees.

Diabetic Medicines

WebMD says Chaga can lower blood sugar. A 2023 review in the journal Molecules also lists Lion’s Mane as lowering blood sugar.

Taken with diabetes medicine, mushroom coffee could push your blood sugar too low. This is called hypoglycaemia, and it can be dangerous.

Immunosuppressant Drugs

You may take immunosuppressants after a transplant or for a health condition. These drugs calm your immune system on purpose.

Mushroom coffee may work against them. WebMD advises avoiding beta-glucans with these drugs, unless your doctor says otherwise.

Chemotherapy Drugs

MSD Manuals says Reishi could make some chemotherapy drugs less effective. If you’re having cancer treatment, check with your care team before trying any mushroom product.

Anyone on regular medication is in the group who should not drink mushroom coffee without checking first. Ask your doctor or pharmacist.

For a mushroom-specific, evidence-based look, read does lion’s mane coffee work?

Blood pressure medicine needs its own section, though. That’s because Reishi may affect blood pressure directly.

People with Low Blood Pressure

Do medicinal mushrooms affect blood pressure? Some may. MSD Manuals says Reishi “might lower blood pressure”.

It warns that Reishi plus blood pressure pills could make your blood pressure drop too low.

If your blood pressure is already low, that could cause:

• Dizziness
• Fainting
• Fatigue or weakness
• Nausea

If you have low blood pressure, ask your doctor before trying mushroom coffee. The same goes if you take blood pressure pills.

Your kidneys are another organ to think about, especially if your blend contains Chaga.

People with Kidney Problems

Chaga is high in oxalates, natural compounds that can form kidney stones. WebMD says people with kidney disease or a history of kidney stones should not take Chaga.

This is not just theory. Doctors have published case reports of serious kidney damage after long-term Chaga use. You can read one from 2020 and another from 2022.

The upshot?

These cases are rare, but the stakes are high. People with kidney problems belong on the list of who should not drink mushroom coffee containing Chaga. Ask your doctor before trying any blend.

Your gut is the next place people notice problems, just as my friend Sarah did.

People with Sensitive Stomachs

Remember Sarah’s stomach being “in knots”? That kind of reaction does happen.

A 2025 systematic review of Lion’s Mane studies found stomach discomfort, nausea and diarrhoea in some human trials. The authors said side effects were not often seen. In the main trial, stomach complaints were about as common on a dummy pill.

Mushroom powders add fibre, and coffee itself can upset some stomachs. If you have a sensitive gut, start with a small amount and see how you feel.

My guide to the side effects of mushroom coffee covers these reactions in more detail.

Then there is one ingredient many people forget is still in the cup.

People Sensitive to Caffeine

The catch?

Most mushroom coffee is made with real coffee, so it still contains caffeine. Some blends have less than a normal cup, but not all do.

Caffeine can cause a short rise in blood pressure. Mayo Clinic says this happens mainly in people who don’t drink caffeine often.

So, can mushroom coffee cause high blood pressure? The caffeine may cause a brief spike, while Reishi may lower it. That mixed picture is why mushroom coffee and blood pressure questions are best taken to your doctor.

Caffeine can also bring on poor sleep, nervousness or a fast heartbeat. Mayo Clinic adds that it may increase symptoms of anxiety.

If that sounds like you, you may be among those who should not drink mushroom coffee. Learn how to choose mushroom coffee with a lower caffeine level, or try a caffeine-free mushroom tincture. And if none of these eight groups fits you, a few simple habits lower the risk even further.

How to Minimise Risk If You Still Want to Try It

Curious about mushroom coffee but want to avoid side effects? Start with what goes into your cup.

Choose a Safe Mushroom Coffee Blend

With so many brands available, how do you find a safer option? Check for these three things:

• Clear mushroom details: The label should name each mushroom and its dose per cup. It should also say which part is used, such as fruiting body or mycelium.
• Real customer reviews: Check reviews when you compare the best mushroom coffee brands. Other buyers’ experiences can help you find reliable brands.
• Clear caffeine content: The packaging should state the caffeine per cup. If it’s vague, that’s a red flag!

Consider the numbers.

For reference, our own Lion’s Mane Coffee lists 1,800mg of organic Lion’s Mane per cup. It has about 50mg of caffeine per cup and contains no other mushrooms.

Because it holds only Lion’s Mane, the Chaga kidney warning above doesn’t apply to it. Every other caution in this article still does, including blood thinners, surgery, diabetes medicine and pregnancy.

Not sure if any of this applies to you? Go back over the eight groups above. If you take medicines or have a health condition, speak to your doctor first.

Once you have a blend you trust, the next question is how much to drink.

Slow Introduction & Dosage Recommendations

Once you find a well-labelled blend, start slow:

• Begin with one cup in the morning, rather than jumping straight to two.
• Keep a journal or use a health-tracking app to note changes in energy, focus, digestion or mood.

When should you stop drinking mushroom coffee? If you notice any side effects, stop straight away.

Otherwise, I suggest watching how you feel for about three weeks.

If you feel good, you can move up to two cups a day. Keep your last cup well before bedtime, since it still contains caffeine.

Long-term use matters too. MSD Manuals says taking powdered Reishi for more than a month could damage the liver.

And if coffee isn’t the right fit at all, there are other ways to take mushrooms.

Alternative Ways to Reap Mushroom Benefits

Want what mushrooms offer, but without the coffee? Then you could try:

• Mushroom drops: Mix them into tea or your favourite drink.
• Mushroom capsules: Swallow them with some water.
• Mushroom powder: Stir it into tea, smoothies or porridge.

These skip the caffeine, but anyone who should not drink mushroom coffee needs the same care here. A Chaga tincture has the same kidney and blood-thinning concerns as a Chaga coffee.

That still leaves a few specific questions people ask us again and again.

Frequently Asked Questions

Conclusion: Should You Drink It or Skip It?

So, who should not drink mushroom coffee? The answer isn’t simple, but there is a clear pattern.

Anyone with a mushroom allergy, or who is pregnant or breastfeeding, should avoid it. So should anyone on blood thinners or immunosuppressants, or with kidney disease if the blend has Chaga. People with autoimmune conditions or low blood pressure, or on other medication, should ask a doctor first.

If you’re unsure who shouldn’t drink mushroom coffee in your own situation, ask your doctor first.

Want the benefits without having them in coffee? Mushroom tinctures, capsules or powders skip the caffeine. But the same mushroom cautions still apply.

So where does that leave you?

Mushroom coffee can suit a lot of people. It just isn’t for everyone, and that’s worth knowing before your first cup.

Still weighing it up? Read does mushroom coffee work? for the evidence.