All posts by : Ana Aleksic

I used chaga during my first pregnancy and took it occasionally while breastfeeding my second. When I was researching the data on it while pregnant, I couldn’t find any good information—and that’s still the case. This mini-monograph is here to fill in the gap and give you a helpful overview of chaga research, energetics, and traditional knowledge. If you feel called or curious about this mushroom and are pregnant or breastfeeding, read on. 

Disclaimer: This post is for informational purposes only. None of the information here should be taken as medical advice. Even if a remedy is classified as safe in Herbal Doula blog posts based on the existing evidence, that doesn’t mean it’s safe for you. The classifications in the database are just a general reference point. Follow your body, keep track of your response, and consult an herbalist, holistic practitioner, or anyone else you feel may help you if you need expert advice.

Affiliate Disclosure: I only include products I think are useful for my readers. If you buy through links on this page, Herbal Doula may earn a small commission. This supports small business owners who make these products and my work as an independent scientist and natural health advocate.

Chaga Safety Categorization

Pregnancy Safety:

Caution

Labor Safety:

Caution

Breastfeeding Safety:

Caution

Due to a lack of data, chaga should be used with caution during pregnancy and labor. 

Chaga is likely safe during breastfeeding, although caution is still recommended since more data are needed to confirm this.

Due to potentially high oxalate content, it’s safest to take lower doses of thermally treated chaga along with a diet high in calcium.

Chaga should be avoided by women with kidney disease.

Read Next:

• Echinacea Benefits and Safety in Pregnancy & Breastfeeding

A Holistic Intro to Chaga

Chaga, also known as Inonotus obliquus, is a medicinal mushroom that grows mostly on birch trees in cold climates. Folk herbalists in Siberia, northern Canada, and northern Asia have used it for centuries as an immune booster and general health tonic (Balandaykin et al., 2015).

Learning from chaga in nature

Chaga is not pretty at first glance—it resembles a black, burn-coal-like tumor. In fact, chaga is said to be parasitic to the host tree it grows on, slowly leeching nutrients and active compounds.

But if we trust in the wisdom of nature, we can unveil that chaga is not just a parasitic mushroom. While the tree is alive, chaga grows slowly—no more than 10 cm over 10–15 years. After many years, the host tree dies and chaga fruiting bodies sprout, helping chaga achieve faster growth and reproduction (Szychowski et al., 2021).

Therefore, chaga doesn’t destroy birch forests but forms a new ecosystem with them. It’s only unsustainable industrial practices that harm the birch trees chaga grows on.

Analyses estimate that chaga naturally grows on 1-5% of birch trees. Reports show higher rates of chaga colonization on mature birch trees and in forests disturbed by humans (Kuz’michev et al., 2001; Brydon-Williams 2019; Balandaykin et al., 2015).

Could it be that chaga is nature’s way of fighting human influence and protecting the immune system of the forests it grows in? 

This piece is important to understanding the energetics and actions of chaga. We’ll get more into chaga sustainability in later chapters of this article.

Chaga traditional & modern uses

Chaga is prized for its unique, coffee-like aroma. It’s recently become popular in mushroom coffee blends, often alongside reishi and cordyceps.

Traditionally, people have used chaga to support the immune system, gut health, and energy levels. In folk herbalism, chaga is also used externally on wounds to prevent infection and encourage healing. It was also recommended for heart and liver diseases (Szychowski et al., 2021).

Limited studies suggest that chaga is packed with antioxidants, nutrients, and active compounds that may help reduce inflammation, offset oxidative stress, balance blood sugar, fight viruses and parasites, and strengthen the immune response (Szychowski et al., 2021).

The first person to popularize chaga’s supportive effect in cancer treatment was the Russian writer Aleksander Solzhenitsyn in his 1966 semi-autobiographical novel Cancer Ward.

Interestingly, a whole line of research is now dedicated to exploring chaga’s potential in fighting cancer. So far, these studies are limited to animals and cells (Géry et al., 2018).

Summary

Chaga, a parasitic fungus found on birch trees, is prized for its unique aroma and use in traditional folk medicine of the North. It is believed to have potential benefits for reducing inflammation, strengthening the immune system, and supporting gut health. 

Chaga Active Compounds

The most important active compounds and nutrients in chaga are (Ma et al., 2013; Géry et al., 2018; Szychowski et al., 2021; Géry et al., 2018; Abu-Reidah et al., 2021):

• Antioxidants and antioxidant enzymes—help neutralize oxidative stress in the body
• Polysaccharides like beta-glucans—support the immune system
• Triterpenes and ergosterol—may help reduce inflammation
• Phenolics like salicylic acid—also found in birch and known as “nature’s aspirin”
• Betulin and betulinic acid—may help fight inflammation and microbial infections
• Melanins—a dark pigment with broad antioxidant activity
• B vitamins, vitamin E, vitamin D2, pro-vitamin A, and vitamin K
• Potassium, calcium, magnesium, iron, copper, zinc, selenium, sulfur, and iodine

Chaga Research & Safety Data

In Pregnancy and labor

There are no studies on chaga in pregnant women.

No published analysis or questionnaire has yet summarized the use of chaga in pregnant women either.

There are some reports of chaga use among indigenous people and a couple of studies in pregnant or developing animals.

The Nenets People

There are reports of chaga being used in labor and during the postpartum among the Tundra Nenets people in Russia. Women and children would cut the chaga from trees and collect it in big sacks. They would then pack it in sledges and used it for the rest of the year as tea or medicinal wash (Ravna, 2019).

One midwife observing the labor of a Nenet woman wrote:

“Once, one of the women began to give birth unexpectedly quickly. She started to give birth in the tundra, where nothing [was prepared], no firewood, nothing. She says: Let me give birth in the traditional way. I replied: I didn’t learn how to assist in the traditional way. I have never seen it, you know. Let’s try to give birth as they give birth at the hospitals. It turns out to be that she had already tied a rope to the poles [inside of the tent]. Well, I did not carefully consider the rope, maybe it was a special one, made from reindeer sinews. Well, it’s short, tied to only two poles. She holds it with both hands, and squats. Her body is covered with an everyday Âguška (a women’s winter coat made from reindeer skins). She has also prepared a bowl with boiled water and a bowl with chaga. The reindeer sinews for tying the umbilical cord were also there. The navel will be treated also with the same chaga water.”

“This birth went well. Right after she gave birth to her child, she sat on her knees and under her she put the same type of Sphagnum moss as she had picked and dried for the cradle. According to Linné, the Sámi women also used the Sphagnum moss as pads.”

WOW! Mindblowing.

Reading this account, I’m a bit frustrated to read that this medical midwife wanted to disturb the mother’s instincts by telling her to “give birth like in the hospital.” But isn’t it incredible that this woman prepared herself chaga tea and reindeer sinew ropes in the wild and just went on to have an amazing and totally normal birth, at the shock of the attending “midwife.”

Animal studies

In one study on pregnant mice, chaga polysaccharides reduced miscarriage rates in animals with toxoplasmosis (infection with a parasite called Toxoplasma gondii). Chaga prevented a drop in progesterone and estrogen and increased levels of protective antioxidant enzymes (superoxide dismutase/SOD and glutathione /GSH). Additionally, chaga reduced inflammatory cytokines and increased the production of an anti-inflammatory cytokine IL-10 (Xu et al., 2020).

The authors concluded that chaga may help protect mice against the adverse effects caused by toxoplasmosis by helping balance the immune system and soothing the inflammatory response.

In another study on zebrafish exposed to high levels of UVB radiation, chaga reduced DNA damage and enhanced the activity of DNA-repair genes. This helped zebrafish develop normally (Eid et al., 2021).

It’s hard to interpret this study as there’s a long way to go from zebrafish to humans (although zebrafish have more than 70% genome similarity with humans). Still, the results suggest that chaga helps protect the genetic material in developing organisms even when they are exposed to a harmful influence like high artificial UVB radiation.

Theoretically, chaga may play a role in preventing genetic disorders in the preconception or conception stage, but this has not been proven.

Importantly, these and other animal studies highlight that chaga has overall protective and balancing action. There are no mentions of its toxicity or adverse effects on pregnancy in the literature.

On the other hand, chaga extracts can be high in various bioactive compounds, including those that come from birch trees. At high dosages, it’s possible that these compounds may cross the placenta and enter the baby’s circulation. In general, very high doses of herbs and medicinal mushrooms are not recommended during pregnancy unless prescribed for a specific issue over a set period of time.

Real-world use

Chaga is a common ingredient in mushroom coffee. These products are usually marketed as safe for pregnant and breastfeeding women. Many women report using mushroom coffee during pregnancy as a healthier alternative to regular coffee.

Chaga supplements, on the other hand, typically come with disclaimers that their use should be avoided during pregnancy and breastfeeding due to a lack of safety data. Supplement manufacturers need to place this warning on all products due to liability and regulations.

Postpartum & Breastfeeding

There are no human studies examining chaga use and safety while breastfeeding. There are limited accounts of chaga use among indigenous people during the postpartum.

The Nenets People

When a baby is born, the Nenets say: Syurmbăda ŋătsekem’ nja”măva”(We managed to catch the running child). The methods of helping the mother after birth are physical, psychological, and spiritual. Chaga is a part of them (Ravna, 2019).

A wise Nenet elder woman helping at birth will prepare a special traditional postpartum mixture. She will roll up smouldering embers and the fat of a wild reindeer with a little bit of fur and lay it on the burning fire to infuse the pregnant woman after birth. The elder will completely fumigate the pregnant woman’s body, legs and face. This process is translated as “purifying” but I see this as a limitation of our language and perception. The whole ritual seems to have protective and energizing qualities.

After this procedure is completed, she will make a special mix of chaga. One woman explained this process as follows:

“We mix the chaga with boiling water, then this liquid is cooled to approx. 36 degrees. Then we washed this mix all over her face, hands, and body. The remaining chaga mix we splash on the hot coals of the fire three times. It turns into our steam bath or sauna, for the Nenets. This is one of the serious rituals. After this ritual, we dress everything clean, naturally.”

“After this, the elder woman performs the same ritual again: she fumigates the baby, the cradle, all the objects that the woman used, her sledges and all the people in her tent, who return after the birth is finished. Only after that can the new mother get food.”

What a fascinating ritual!

From this account, we can see that chaga played an important role in both birth and the postpartum of indigenous people of the North. All in all, it was revered as protective, purifying, and energizing—an essential and ceremonial part of birth and the immediate postpartum. 

There are also other mentions of chaga being used traditionally to support lactation in breastfeeding mothers, but both scientific reviews and herbalism books summarizing these uses are lacking.

Research & real-world data

Although there is no research to confirm that chaga is safe while breastfeeding, there are no reports of it having a negative influence on the breastfeeding mother or her baby.

Small amounts of chaga’s active compounds may pass into breast milk. This is not necessarily bad. In fact, some women anecdotally use this to their and their baby’s advantage in case of colds or sickness.

Most blog posts will tell you to consult your doctor before use, but I personally don’t think this is realistic unless your doctor is a naturopath or someone with extensive herbal knowledge. Most doctors will just tell you not to take any herbs or mushrooms while pregnant or breastfeeding.

If you are considering using chaga while breastfeeding or pregnant, take your own constitution and individual health goals into account. Ask yourself how this mushroom may support you in your pregnancy and postpartum journey—it may be the right choice for some and not for others. Individualization is key.

Chaga Mushroom Energetics & Actions

Here are the main herbal actions of chaga:

• Adaptogenic
• Immunomodulating
• Cooling
• Drying
• Tonic

From a Western herbal perspective, chaga is considered an adaptogenic mushroom. It helps the body adapt to stressors and promotes overall balance and well-being. It’s also considered an immunomodulating herb, helping to support the immune system without overstimulating it.

From an energetic perspective, chaga is considered cooling and drying. It’s a good choice for people who tend to feel warm or overheated. It’s also considered to be a tonic, helping to support overall health and vitality. This is especially important during the postpartum, when many tonic natural remedies can act as strong allies.

According to Chinese medicine, chaga is sweet, cooling, balancing, and grounding. It has the action of pulling in of the extremes and sending energy down through the center of the body. This is one of the reasons why some women work with chaga during pregnancy and postpartum.

In astroherbalism, chaga is usually associated with the planet Saturn and the earth element.

Saturn is a grounding planet, and chaga is said to reflect this grounding energy. Saturn is also associated with the hard structures that hold our body, such as the skeletal system—another reason why chaga is cherished during the postpartum. In general, it’s a great choice for individuals who need grounding, pulling-in action, and structural support.

Chaga Benefits for Pregnant & Breastfeeding Women

For women on their wild pregnancy and postpartum journey, who embrace a natural and holistic approach to health, chaga can be a valuable ally. Here are some of the ways chaga can support a healthy pregnancy (Lu et al., 2021; Szychowski et al., 2020):

• Immune support & nutrient replenishment: Pregnancy and breastfeeding can put extra demands on your immune system and nutrient stores. Chaga is packed with nutrients, antioxidants, polyphenols, and beta-glucans, which can help replete nutrients and support a healthy immune response.
• Anti-Inflammatory support: Chaga’s anti-inflammatory properties may help in case you feel flare-ups or are dealing with chronic inflammation.
• Energizing: Chaga has a long-standing tradition of being used as an energizing and adaptogenic herb, helping to boost energy levels, increase vitality, and boost resilience during stressful and demanding times.
• Blood sugar balance: Chaga may help balance blood sugar and insulin sensitivity, as well as support normal metabolic activity in the body. It’s being researched in diabetes and insulin resistance. This may be helpful for women worried about gestational diabetes, along with a healthy diet and lifestyle.
• Gut health: Pregnancy (and sometimes even the postpartum) can bring on digestive discomfort, bloating, constipation, and indigestion. Chaga helps support digestion and overall gut health.

Traditionally, chaga has been used by indigenous populations—such as in Siberia—to support postpartum recovery. Its immune-boosting and energizing properties make it a valuable ally for new mothers, helping to support the transition into motherhood.

Incorporating chaga into your diet can be a natural way to support a health pregnancy and postpartum journey. However, it’s important to choose a sustainable and uncontaminated source, which I’ll discuss in the next section.

Chaga Dosage, Formulations & How to Use

You can use chaga as tea, tincture, or dried extract.

Double extraction tinctures are superior to other formulations since they contain both water- and alcohol-soluble active compounds. If you’re taking it as a dried extract, you can use it in pill form or add the powder to your tea or beverage of choice.

The typical dried extract dosage is 500 to 1,500 mg per day.

When taken as a tincture, it’s usually recommended to use 2 to 3 droppers per serving, several times per day. One dropper is about 20 drops or 1 ml.

You can also experiment with a more energetic, lower “drop” dosage of anywhere from 3 to 10 drops (read about Matthew Wood’s take on this if you’re intrigued!)

Chaga Precautions, Sustainability & Harvesting Issues

Contamination

Only young and fresh sclerotia growing on birches, harvested throughout the year, are used medically. Sclerotia should be harvested in uncontaminated areas distant from sources of pollution, which may accumulate in the fungus (Szychowski et al., 2021).

In the natural environment, chaga grows in a cool climate with high seasonal temperature fluctuations. In response to numerous stressors, chaga produces antioxidants and many bioactive compounds that carry the health benefits mentioned in this article (Szychowski et al., 2021).

Allergies & sensitivities

Some people may be allergic or sensitive to compounds in chaga. Use is not recommended if you are allergic to birch. As always, track your individual response and stop using if you react negatively.

Oxalates

Chaga may be high in oxalates, which can damage the kidneys in large amounts. Oxalates are reduced by exposing the mushroom to heat, best by boiling. They also bind to calcium, which is why high-oxalate foods like spinach are usually prepared with calcium-rich foods like butter and milk.

Chaga should not be consumed raw. However, the exact extent to which treating the mushroom with heat will lower oxalate content in different formulations is hard to estimate.

Toxicity

There are three known cases of kidney toxicity associated with large intakes of chaga powder that was high in oxalates.

In the first case, a 75-year-old Japanese female with liver cancer developed kidney failure after taking 4-5 teaspoons of chaga powder daily for 6 months (Kikuchi et al., 2014).

The second case involved a 49-year-old Korean male with atopic dermatitis who also developed kidney failure after taking 3 grams of chaga powder daily for 4 years followed by 9 grams daily for one year. Analysis of the chaga powder used found 0.14 grams oxalate per gram, which amounted to moderate oxalate intake at 9 g/daily (Lee et al., 2020).

The third case was a 69-year-old male taking chaga mushroom powder 10-15 grams daily for 3 months. He was diagnosed with acute oxalate nephropathy with serious kidney damage (Kwon et al., 2022).

Most case reports didn’t specify the exact type of chaga preparation that was used (Was it the canker or mycelium? Was it an extract or just dried mushroom powder? Was the mushroom raw? Where did the mushroom come from?).

It’s also important to know that soluble oxalates are a much bigger health threat than insoluble oxalates.

One analyst found the following oxalate levels in different chaga samples made of the canker (this part is traditionally used) (Leet et al., 2020):

• Russian chaga extract: 97.6 mg/g of soluble oxalic acid and 24mg/g of insoluble oxalic acid
• Finnish chaga extract: 55.62 mg/g of soluble oxalates and 9.5mg/g of insoluble oxalates
• Japan Food Research Laboratories: 112mg/g in one sample, 28 mg/g in another

To put this into perspective, typical diets contain 200 to 300 mg of oxalate daily. Yet, spinach contains 4-9 mg/g. So, 300g of raw spinach will give you almost 3000 mg of oxalates. However, cooking spinach reduces the oxalate content down by 30-87% (Chai & Liebman, 2005).

Overharvesting & sustainability issues

It’s important to choose chaga that has been harvested sustainably and ethically. As chaga is becoming more popular worldwide, overharvesting and its impact on indigenous populations who rely on chaga as a traditional medicine is growing into a serious concern.

Since chaga requires a living host, it can’t be farmed on dead logs. The only response to increasing demand has become overforaging and overharvesting. Unfortunately, this has led to many unsustainable practices that are damaging forests and indigenous populations alike (read more in this article).

To ensure that you’re choosing a sustainable and ethical source of chaga, look for suppliers who are transparent about their harvesting practices. Ideally, choose chaga that has been harvested in a way that supports local communities and traditional harvesting practices. Additionally, make sure that the chaga is being harvested from a healthy population of trees and that the supplier is not over-harvesting from a single tree or location.

Choosing a sustainable source of chaga not only supports local communities and traditional harvesting practices but also ensures that this valuable resource will be available for future generations.

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What Is the Bottom Line?

Chaga is a nutrient-dense adaptogenic mushroom that can be a wonderful ally for women, especially during the postpartum. It may help balance the immune response, boost energy, and help you become more grounded as you tackle the everyday demands of motherhood.

However, the safety data on chaga is sparse. No studies looked at its safety in pregnant or breastfeeding women. The existing animal studies and literature reviews suggest that it has protective effects.

Several cases of oxalate toxicity causing kidney damage have been reported with very high doses of chaga, so some caution is recommended. For this reason, it’s safest to take chaga occasionally, at the recommended doses, and alongside a diet high in calcium.

There are also reports of chaga being traditionally used during labor and postpartum among the indigenous people of North Russia.

Chaga is also an ingredient in popular mushroom coffee blends.

All in all, chaga should be used with caution during pregnancy and labor due to a lack of data. It’s likely safe during breastfeeding, although more data are needed to confirm this.

Stick to the recommended dosages, track your response, and consult an experienced herbalist or natural practitioner if you need guidance.

>>>>> Read the report on Moringa safety in pregnancy and breastfeeding.

Did you use chaga?

Let me know about your experience in the comments and share this article if you found it useful!