Most people do well on mushroom coffee, and the most common side effects come from the caffeine, not the mushrooms. A few people notice digestive changes when they first switch, and some specific mushrooms deserve care for certain health conditions. Here's what to know so you can switch with confidence.
1. Caffeine side effects
If your mushroom coffee is made with real coffee, it has caffeine. Too much can cause jitters, a racing heart, anxiety or poor sleep. The FDA cites 400mg a day, about two to three 12-ounce cups of coffee, as an amount not generally linked to negative effects for most adults (FDA). Our Signature Mushroom Coffee Blend has about 90mg per scoop, and it's paired with L-theanine, which many people say smooths out the buzz. To protect your sleep, see How Late Can You Drink Coffee Before Bed?
2. Digestive changes
Some people notice mild bloating or looser stools during the first week of switching. Mushrooms contain natural fibers, and any new food can take a few days to settle in. Starting with half a scoop and drinking it with food usually helps. If coffee itself bothers your stomach, see Coffee Upsets Your Stomach?
3. Mushroom allergies
If you're allergic to mushrooms or molds, skip mushroom coffee or check with your doctor first.
4. Specific mushrooms and health conditions
- Chaga is naturally high in oxalates. Rare kidney problems have been reported in people who took large amounts of chaga powder daily for months (case report). If you have kidney problems or a history of kidney stones, check with your provider. See Chaga Tea.
- Cordyceps: people with autoimmune conditions, or who take blood thinners or blood sugar medication, should talk to their provider first. See Cordyceps Benefits.
- Lion's mane and tremella are eaten as foods and are generally well tolerated.
5. Pregnancy and medications
If you're pregnant, nursing or taking prescription medication, talk to your healthcare provider before adding functional mushrooms. Pregnant women are commonly advised to keep caffeine to about 200mg a day.
6. The side effect nobody talks about: contaminants
Coffee and mushrooms can both pick up mold, mycotoxins and heavy metals from where they're grown and stored. Cheap blends that skip testing can carry more than you'd want. That's why we test every batch and publish the results. See Mold-Free Coffee.
How to start mushroom coffee the easy way
- Start with half a scoop for the first few days.
- Drink it in the morning, with or after breakfast if your stomach is sensitive.
- Have water and electrolytes first thing.
- Give it 2 to 4 weeks of daily use before judging how you feel.
Our Signature Mushroom Coffee Blend
Our Signature Mushroom Coffee Blend lists every ingredient and amount on the label: organic Arabica coffee, 8:1 fruiting-body extracts of lion's mane, cordyceps, chaga and tremella, Alpha-GPC, L-theanine, organic ginkgo, organic cacao and a full gram of organic Irish sea moss. About 90mg of caffeine, no sweeteners and no fillers. Every batch is third-party tested for mold, mycotoxins, glyphosate and heavy metals.
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Frequently asked questions
Does mushroom coffee have side effects?
Most side effects come from caffeine. Some people notice mild digestive changes when they start. People with mushroom allergies, kidney concerns or certain medications should check with their provider.
Can mushroom coffee upset your stomach?
It can for a few days while you adjust. Start with half a scoop and drink it with food.
Is mushroom coffee safe to drink every day?
For most healthy adults, yes, in the same amounts as regular coffee.
Can mushroom coffee cause anxiety?
Caffeine can. Blends with L-theanine and moderate caffeine, like ours at about 90mg, are often easier on people who are sensitive.
Who should not drink mushroom coffee?
People with mushroom allergies, and anyone pregnant, nursing, on medication or with kidney problems should check with their healthcare provider first.