What are the negative side effects of mushroom coffee?
Mushroom coffee side effects can cause nausea, bloating, altered functionality of certain medications and an increased risk of allergic reactions in those who are sensitive to mushrooms.
But that can be avoided if you follow the tips I will give you towards the end of this article.
Now, you may be wondering if the benefits outweigh the side effects. My simple answer is YES. Mushroom coffee's benefits outweigh the side effects by miles.

Let's dive right in, shall we?
My Three-Year Experiment with Mushroom Coffee
Call me arrogant, but after spending so many years in the coffee industry, I thought I knew everything about a good cup of coffee.
I'm James Bellis, founder of Balance Coffee, a coffee entrepreneur, and a biohacker. With 12+ years in the industry, I hold an SCA Coffee Skills Diploma and specialise in healthy coffee, biohacking, and adaptogenic mushrooms. My full bio is here.
I’d tasted some of the world's premium speciality coffee, studied extraction methods, worked as a professional barista and built a business around high-quality, toxin-free coffee.
But something was missing. No matter how well I sourced my beans or optimised my brewing technique, I kept running into the same issues. My energy crashed, and I never felt I could do deep work. I started researching and came across the idea of upgrading coffee with mushrooms.
I consulted my nutritionist, author and dear friend, Clementine Rose, to learn more about mushroom coffee.
Clementine Rose is a BANT-registered nutritional therapist who specialises in gut health, hormones, and weight management. She has worked with Google’s Kyros Project, ensuring nutritionally refined products. Her full bio is here.
Here is a quote from Clementine:
While functional mushrooms offer potential health benefits, their effects vary based on individual physiology, existing health conditions, and medication interactions. Tracking personal data, as James did, is essential to understand how mushroom coffee affects you.
She asked me to try it, and I did. In the first few weeks, I genuinely felt more energised.
That’s when I thought: What if I tested its effects over several years? I decided to conduct a three-year experiment. But instead of focusing on the benefits, my nutritionist encouraged me to track the side effects of mushroom coffee.

Using health-tracking apps, I documented how my body responded, morning, afternoon, and night. So, what are the side effects of mushroom coffee? Let’s dive into the science and my personal experience.
The Science Behind Mushroom Coffee Side Effects
During this three-year experiment, I used the science behind mushroom coffee as my compass.
I studied health and peer-reviewed journals to discover what they said about mushroom coffee’s potential side effects.
What Research Says About Common Side Effects
So, first things first, a cup of mushroom coffee usually consists of ground medicinal mushrooms and coffee beans.
You can even mix a few drops of medicinal mushroom tinctures in a traditional coffee mug, converting it into mushroom coffee.

Health Harvard states that medicinal mushrooms like Reishi, Cordyceps, Chaga, and Lion’s Mane are commonly used in coffee blends or tinctures because of their health benefits.
If you’re highly sensitive to caffeine, MedicineNet suggests that a potential mushroom coffee side effect could be nausea or bloatedness.
Mushroom coffee still contains caffeine but in lower amounts than regular coffee. The acidic nature of all kinds of coffee could also cause this mushroom coffee side effect.
According to Healthline, when you brew coffee, you release various acids into the caffeine drink, controlling how bitter your mushroom coffee tastes.
Those acids make this beverage slightly acidic. When you drink something slightly acidic, your stomach produces more acid.
A study published in the National Library of Medicine indicates caffeine increases stomach acid production.
Excess stomach acid can cause bloatedness and heartburn, especially in people with sensitive stomachs.
However, research on whether mushroom coffee specifically causes bloating or acidity is still limited.
Another side effect of mushroom coffee is allergic reactions. WebMD warns you to avoid drinking mushroom coffee if you’re allergic to mushrooms.
The Role of Specific Mushrooms in Side Effects
Depending on the mushrooms used, mushroom coffee can be many different types. Lion’s Mane, chaga, Reishi, or cordyceps mushrooms are the most common.
Some people also like to add the best mushroom tincture drops to their daily coffee as a way of enhancing its health benefits.

Do these have any role in the potential side effects of mushroom coffee? Let’s cover what science has found so far.
Chaga Mushrooms
Chaga mushrooms are known for having compounds that strengthen the immune system.
But, if taken in high doses, you can face the health risks of mushroom coffee.
A WebMD article highlights that Chaga mushrooms are rich in oxalate, a chemical that damages the kidneys.
The National Library of Medicine published a recent review of the harmful effects of taking Chaga mushrooms.
It indicates that taking high doses of around 10 - 15 grams of Chaga mushrooms for a long time increases oxalate levels in the blood, causing kidney damage.
According to a Healthline blog, Chaga mushrooms contain a protein that stops the blood from clotting.
This action may increase the risk of bruising or bleeding, especially in people taking blood thinners or those with bleeding disorders, making it a possible mushroom coffee side effect.
A beneficial effect of chaga mushrooms is that they lower blood sugar. However, this can become one of the mushroom coffee cons if it's taken with blood sugar medications.
WebMD states that this combo could make the blood sugar fall too low.
Reishi Mushrooms
How do Reishi mushrooms influence the negative side effects of mushroom coffee?
If you take medications like blood thinners or have a bleeding disorder, Reishi mushrooms may increase the risk of bleeding or bruising.
According to WebMD, this makes it one of the potential dangers of mushroom coffee. Reishi mushrooms are also known to boost the activity of our immune system.
If you take medication that reduces immune system activity, mushroom coffee may interact with such medications and reverse those effects.
In a nutshell, before deciding to take Reishi coffee, you need to consult your doctor. Once you have, be sure to read my article on whether you can drink mushroom coffee daily. It contains nuggets that will help you.
Cordyceps Mushrooms
Some medical blogs advise that cordyceps mushrooms in coffee may interact with medications, affecting their efficacy.
According to WebMD, mushroom coffee may reduce the efficacy of medicine if you consume it while suppressing immune system activity.
Another one of the mushroom coffee health risks is that it may slow down the formation of blood clots.
This may increase the chances of bleeding and bruising, especially in people on blood thinners and those with bleeding disorders.
My Personal Data (Experimenting with Mushroom Coffee)
After thoroughly studying the science behind mushroom coffee’s side effects, I conducted my experiment.
Over three years, I decided to brew coffee from the best mushroom coffee blends and actively track my health using quantifiable metrics.

I have written the article on how to brew mushroom coffee so you can follow the step-by-step guide and do it yourself.
Setting Up My Health Metrics
The first thought that popped into my head was, ‘What health factors can I easily track to find out the answer to my burning question, ‘Does mushroom coffee have side effects?’
I consulted with my nutritionist, Clementine Rose, who guided me in monitoring my sleeping patterns, my energy and focus levels, and my gut health.
She advised that I could use health apps to maintain my data log.
That would help me determine whether I’m experiencing any harmful effects from mushroom coffee. Here’s how I did it.
Sleep Tracking
I tracked my sleep patterns using the Oura Ring and the Sleep Cycle app to see if mushroom coffee affected my sleep quality.

Image Source: Oura Ring
Oura Ring is a wearable sleep tracker that monitors:
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Sleep duration – How many hours I slept.
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Deep & REM sleep – These are the stages of memory and recovery.
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Resting heart rate & HRV – Indicators of relaxation and recovery.
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Sleep efficiency – How well I slept through the night.
It gives a sleep score each night based on these factors, helping me spot trends.
I wore the ring every night and checked my sleep score each morning. If I saw a decline in my sleep quality after drinking mushroom coffee late in the day, it suggested caffeine might be affecting me.
Sleep Cycle is a smart alarm app that:
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Tracks sleep phases using sound analysis.
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Wakes you up at the lightest sleep stage, making mornings feel easier.
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Shows sleep trends over time.
I placed my phone near my pillow, and Sleep Cycle recorded my sleep quality. I compared its data with the Oura Ring to see if both tools showed similar patterns.
Energy and Cognitive Function
Mushroom coffee is touted for its long and mild energy boosts with improvements in brain power.
I used the RescueTime app to measure my work productivity. I also noted my focus and energy levels in the Day One journaling app.

Image Source: RescueTime app
I ran RescueTime app on my laptop, and it monitors how long I spend time on various apps and websites, telling me about my:
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Focus Time - The number of hours I work on a task with all kinds of distractions blocked.
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Work Hours Breakdown – Shows when I’m most and least productive during the day.
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Daily & Weekly Reports – Summarizes productivity trends and patterns.
At the end of my work day, RescueTime calculates my productivity score and gives me a complete report that tells me how efficiently I use my day.
RescueTime allowed me to compare my productivity score day by day, allowing me to spot trends.
Day One is a journaling app that helped me note my daily experiences.
I noted how alert and energised I felt before and after my first mushroom coffee mug every morning.
Then, the rest of the day, I would come back to my journal after every 4 hours, tracking my focus and energy.
I would rate my focus and energy levels on a scale of 1 to 5: one was horrible, five was awesome, and three was, I can’t tell.
My nutritionist, Clementine, recommended I try this app, Luminosity, to see if mushroom coffee helps improve memory and learning ability.

It’s a brain app designed to test:
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Memory – How well I recall patterns and sequences.
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Attention & Focus – How quickly I can switch between tasks.
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Problem-Solving Skills – How efficiently I complete logic-based challenges.
Lumosity provides short, engaging brain games that target different cognitive skills. Each session includes a mix of exercises designed by neuroscientists.
It first runs an initial assessment to establish my baseline cognitive performance. This score represents my natural ability before any improvements or declines.
Over time, the app adjusts the difficulty of its exercises based on your progress.
I started using Lumosity when I began drinking mushroom coffee, so my baseline scores started from day 0. From there, I continued tracking my performance daily.
Improving my scores over time could suggest a long-term cognitive boost.
If they declined, it might mean that mushroom coffee wasn’t as beneficial for my brain function as expected.
Digestive Health and Mood
Do the negative effects of mushroom coffee include bad digestion and mood? I needed a good app to track these symptoms and find the answer.
I used the Cara Care app to monitor the changes in my stomach health. It works by having a:

Image Source: Cara Care app
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Food Tracker - Records my daily diet, including mushroom coffee.
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Poop Tracker - Helps me identify patterns in my bowel movements.
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Symptom Tracker - Record symptoms like bloatedness, stomach pain, or constipation
I used Cara Care once daily, 1 hour after drinking mushroom coffee, to track how my stomach felt.
I used the Daylio app to better analyse my feelings. It provided a simple interface for creating daily entries.
In it, I could link my mood to what I was doing now.
The app allowed me to set hourly reminders to monitor mood swings before and after drinking coffee.
What My Data Reveals About Side Effects
Time Period | Sleep Quality (Oura Ring & Sleep Cycle) | Longest Sleep Duration (Approx.) | Energy & Focus (RescueTime, Day One, Lumosity) | Day One Journal (1-5 Scale) | Digestive Health (Cara Care) | Mood (Daylio) | Side Effects Noted |
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First Month | Slight decline in deep sleep, mild restlessness | 5 hours | Mild improvement in focus, energy dips in the afternoon | Focus: 3, Energy: 2 | Occasional bloating | No major changes | Mild nausea and bloating after coffee |
3 Months | Sleep stabilising, fewer disruptions | 7 hours | Energy levels more consistent, slight focus improvement | Focus: 4, Energy: 3 | Less bloating, digestion improving | Mood slightly better in mornings | Slight stomach discomfort if consumed on an empty stomach |
6 Months | Sleep quality improved overall, deeper rest | 7.5 hours | Noticeable improvement in attention and problem-solving skills | Focus: 4, Energy: 4 | Digestive issues almost gone | Mood steady, fewer fluctuations | No major side effects, occasional mild nausea |
1 Year | Sleep stable, no major disruptions | 8 hours | Sustained energy, less reliance on caffeine spikes | Focus: 4.5, Energy: 4 | Healthy digestion | Mood noticeably stable, fewer mood swings | No significant side effects |
2 Years | Deep sleep increased slightly, waking up more refreshed | 8.2 hours | Cognitive function improved, better memory recall | Focus: 4.5, Energy: 4.5 | No digestion issues | Mood balanced, less stress | No side effects observed |
3 Years | No negative impact on sleep, consistent deep sleep | 8.5 hours | Best focus and energy levels, mental clarity | Focus: 5, Energy: 5 | Stable digestion | Consistently positive mood | No negative effects, but less energy boost compared to regular coffee |
During my first month of drinking this new caffeine beverage, I thought the mushroom coffee side effect was the same as that of regular coffee.
The Sleep Cycle app showed how disruptive my sleep was. I would get up a few times in the middle of the night, switching from states of wakefulness and shallow sleep.
Deep sleep lasts around 2 hours and would take a good few hours to reach. According to the Oura Ring, I would struggle to get a continuous sleep stretch of 5 hours.

Revisiting my Day One notes, I noticed that my energy and focus levels were low during the first month.
I didn’t get the strong energy boost, which felt to me as one of the drawbacks of mushroom coffee.
There were sudden energy crashes, similar to those you get from regular coffee. This increased my grogginess, adding to the shorter duration of good-quality sleep.
But, I saw a slight positive trend in my focus levels.
The RescueTime app showed that my Focus Time was limited to 60 minutes during the first few days of drinking mushroom coffee.
But as I crossed the 30-day mark, that increased to 90 minutes of Focus Time. I could do a task without wandering to social media platforms for 90 minutes straight.
Moving to Cara Care, the first month was a bit tough on my stomach. I could still feel gassy and bloated. Often, I got nauseous, too.
This was one of the downsides of mushroom coffee that took time to diminish.

If I go to the Daylio app, my mood doesn’t see any change either.
The disadvantages of mushroom coffee, including the lack of good sleep, stomach discomfort, and strong energy kick, gave me an overall miserable mood.
But that was just the beginning. Fast forward three years, and things have changed with the mushroom coffee negative effects.
My sleep is still not perfect, but it's better. I can now get a solid 6-hour stretch most nights. My energy is more stable, with no sudden crashes.
Focus? I’ve stretched my Focus Time to 3 hours straight. Digestion? No more bloating or nausea. And my mood? Let’s say I don’t feel miserable anymore.
Bridging Science and Personal Experience
Once I completed my scientific research and personal experiment, I was curious to collate the data and find the bridge between the two.
Which personal experiment data supported scientific research?
Comparing My Findings with Scientific Research
Clinical studies show how mushroom coffee affects the majority, but they also recognise that side effects vary from person to person.
Some people experience little to no issues, while others face more pronounced effects.

Is mushroom coffee bad for you? Possibly at higher doses. The body reacts differently based on intake levels.
The National Library of Medicine also notes that mushrooms alone aren’t always responsible for side effects.
Factors like age, lifestyle, and underlying medical conditions play a role, too.
That means what I experienced, sleep disruptions, energy fluctuations, and digestion issues, weren’t just about the mushroom coffee side effect. Other variables could have influenced them as well.
There are detailed studies that look at whether mushroom coffee is good for you.
This study by MDPI states it is good for you, but that does not negate the side effects that could follow.
Lessons Learned and Routine Adjustments
For the first month, I took two cups of mushroom coffee daily, one in the morning and one a few hours before bedtime.
I thought two cups wouldn’t do that much harm because there was less caffeine.

But, my Oura Ring and Sleep Cycle app showed that I struggled to get a continuous five-hour sleep stretch.
This mushroom coffee side effect was more prominent.
I expected a smooth energy boost. Instead, I faced sudden crashes, disrupted sleep, and much grogginess.
Looking deeper, research from the National Library of Medicine highlights that consuming caffeine six hours before bedtime can reduce sleep quality.
I cut my intake to one cup in the morning to fix this.
Over time, my sleep improved, my energy dips became less extreme, and my focus time increased from 60 minutes to 90 minutes.
Timing and dosage matter; what works best isn’t just what you drink, when, and how much. And to ensure you’re consuming quality mushroom coffee, you should also know how to choose mushroom coffee.
Key Takeaways for Data-Driven Wellness
After three years of this personal experiment, I’ve put together tried-and-tested, practical takeaways to help you feel healthier while consuming your daily coffee.
How to Safely Integrate Mushroom Coffee into Your Routine
If you’re trying mushroom coffee for the first time, here are some tips that I can give based on my research and experience:
Start Slow
Begin with a small dose, around one cup of mushroom coffee, and observe how your body reacts before increasing it.
Track Your Metrics
Use tools like a sleep tracker, mood journal, and time-tracking software to see how mushroom coffee affects your sleep, energy levels, and stomach.
Listen to your body
Scientific studies stress that a mushroom coffee side effect varies from person to person.
If you experience bloating, stomach pain, sudden crashes, or persistent fatigue, mushroom coffee may not be for you.
Be Mindful of the Timing
Studies indicate drinking coffee less than 6 hours before bedtime reduces sleep quality.
Consult Your Doctor if Needed
If you take medication or have an underlying medical condition, consult a doctor before adding mushroom coffee to your diet.
Expert Opinions and Future Research Directions
Mushroom coffee has gained attention, but experts don’t see it as a one-size-fits-all solution.
Clementine Rose, my nutritionist, states that while functional mushrooms offer potential benefits, they may interact with medications or cause side effects in people with health conditions.

A Healthline article points out that in some studies where a mushroom coffee side effect was reported, other factors such as lifestyle and health conditions were present, too.
This suggests that more research is needed to determine whether medicinal mushrooms alone are responsible or if any mushroom coffee side effect stems from a combination of factors.
Looking ahead, researchers are exploring long-term effects, ideal dosages, and how different mushroom blends impact our brain and the body.
As research evolves, the best approach remains personalisation. Tracking, adjusting, and consulting experts when needed.
People Also Asked Questions
Let’s answer some of the questions you have, shall we?
Are Mushroom Coffee Side Effects Different from Those of Regular Coffee?
While adjusting to mushroom coffee, you may experience jitters, energy crashes, and digestive discomfort. These side effects are similar to regular coffee, but some potential differences exist. One potential side effect of mushroom coffee is that it may interact with medications, altering their effectiveness.
What Are The Most Common Side Effects of Mushroom Coffee?
One common mushroom coffee side effect is sudden energy crashes, though these may decrease over time. Other side effects include:
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Sleep Disruptions – Difficulty reaching deep, continuous sleep, especially when consumed later in the day.
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Digestive Issues – Nausea, bloating, and acidity, which can improve as your body adjusts.
How Do Specific Mushrooms Contribute to Side Effects?
The type of mushroom extract used in mushroom coffee plays a role in determining its side effects. While all medicinal mushrooms offer health benefits, their unique compounds can lead to different effects. For example, chaga mushrooms contain high oxalate levels, which may contribute to kidney issues if consumed excessively.
How Soon Can I Experience Mushroom Coffee Side Effects?
Some mushroom coffee side effects, such as jitters, digestive discomfort, or energy crashes, can be felt within a few hours of drinking it. Other potential side effects, like kidney issues from high oxalate intake or changes in blood clotting, are linked to long-term use at high dosages.
What Tools Can I Use to Track Mushroom Coffee Side Effects Effectively?
You can use apps like Oura Ring and Sleep Cycle to track sleep quality, Daylio for mood changes, RescueTime for focus levels, and Cara Care for digestive health. Keeping a journal of your energy levels and symptoms can also help you spot patterns over time.
What Steps Can I Take to Minimise the Side Effects of Mushroom Coffee?
Start with a low dose and track how your body reacts. Drink it in the morning to avoid sleep disruptions, and stay hydrated to reduce digestive discomfort. If you have health conditions or take medications, consult your doctor first.
Does Mushroom Coffee Affect Blood Pressure?
Mushroom coffee contains caffeine, which can temporarily raise blood pressure, especially in those who don’t regularly consume caffeine. If you take blood pressure medications, consult your doctor before adding them to your routine.
Does Mushroom Coffee Detox Your Body?
Mushroom coffee contains antioxidants that support overall health, but there’s no strong evidence that it directly detoxifies your body.
Conclusion
My experience with mushroom coffee showed that while it offers potential benefits, side effects like sleep disruptions, energy crashes, and digestive discomfort can occur.
Especially if you drink it at the wrong times or in higher doses.
Scientific research also highlights that factors like mushroom dosage, body health, and coffee ingredients influence its effects.
So, if you're trying mushroom coffee, start slow, track how your body responds, and adjust accordingly.
Using apps to monitor sleep, focus, and digestion can help.
While innovation in wellness is exciting, balance is key. Listen to your body, rely on research, and make informed choices for your health.
Like the article said, I have been drinking mushroom coffee for over two years and it's been the best decision I made.
Click here to start your coffee mushroom journey and start improving your energy and focus here today.