CONSUMING COMFREY

Is comfrey really safe to consume?

Comfrey (Symphytum officinale) is a fast-growing perennial herb native to Europe and parts of Asia, but has now naturalized in many parts of the world. It’s known for its large, hairy leaves and bell-shaped purple, blue, or white flowers. Comfrey thrives in moist, fertile soils and is commonly found in gardens and wild areas.

Traditionally, comfrey has been used in herbal medicine for its wound-healing and anti-inflammatory properties. It contains compounds like allantoin, which promotes cell regeneration, and rosmarinic acid, which reduces inflammation. Historically, comfrey was used to treat bruises, sprains, and broken bones, earning it the nickname “knitbone.”

Today modern herbalists use comfrey for many of the same reasons and externally in salves, poultices, and ointments. But most no longer recommended to use it internally due to the presence of pyrrolizidine alkaloids (PAs), which can cause liver damage.

Comfrey contains pyrrolizidine alkaloids (PAs) which are a group of phytochemicals found in over 6,000 plants. PAs can also be found in honey, grains, milk, offal and eggs. In the case of some species of comfrey, a particular PA called echimidine has caused concerns as it is toxic to the liver in mammals. Due to this, medicinal or food products for internal use containing comfrey root, are restricted in many countries, with some permitting the leaf, because it contains far fewer alkaloids.

Echimidine, considered to be the most toxic of the PAs found in comfrey is rarely found in most samples of common comfrey (Symphytum officinale L.) but does seem to appear later studies. This is most likely due to the ability of common comfrey to hybridise with prickly comfrey creating a hybrid called Russian comfrey (Symphytum x uplandicum).

Common comfrey leaves (Symphytum officinale) rarely contains echimidine and tuberous comfrey (Symphytum tuberosum) which has less than 0.02% PAs. The problem nowadays is that common comfrey hybridises to Russian comfrey and some modern analysis shows echimidine appearing in common comfrey as well.

How to tell the difference

Russian comfrey is widely sold to gardeners as the Bocking 14 or 4 hybrid for fertiliser. And because there are seriousconcerns about its PAs, it is important to correctly identify the different species and this can be quite difficult – with the exception of tuberous comfrey.

Common comfrey in the United States mainly has pink to purple flowers with elongated lance shaped leaves, while Russian comfrey, which tends to be a bigger plant with broader pointed leaves and paler pink, violet or blue-purple flowers. Russian comfrey is also the most common variety you will find in gardens, as where common comfrey, is usually found growing wild.

In my opinion, the best time to correctly identify what species you have, is while the plant is in full bloom. Between the size of the plant and the color of the flowers, you should be able to tell the difference. Make sure however, that you 100% with your identification before consuming.

Comfrey’s bad reputation

All too often herbs get a bad rap because of in vitro or animal studies, yet, documentation that demonstrates these actions in vitro or in animals, cannot always be replicated in vivo – i.e. in humans. Animals and humans are obviously not biologically the same. To give you an example, in the Hirono study, researchers found that feeding rats huge quantities of ground comfrey leaves and roots did them no good at all – especially the 2 week old baby rats. Out of 28 rats fed 8% of diet as dry weight comfrey, one showed a liver tumour at 600 days.

This means the average adult human would probably need to ingest around 20,000 comfrey leaves to produce a comparative dose. Assuming 3 dried leaves of comfrey per cup of leaf tea, this equates to drinking 6,666 cups of tea. If you drank a cup of comfrey leaf tea every single day, it would take you over 18 years to reach this level of consumption.

One of the few actual human cases known of comfrey poisoning was a 47 year old woman who took comfrey in excess – a.k.a. overdosing. In this particular case, the woman was consuming excess amounts of comfrey tea (up to 10 cups daily), and taking pill supplements of comfrey for over thirteen years. No wonder she ended up with liver issues! Sadly for comfrey, this situation condemned the plant forever.

On the contrary, I cant help but wonder what the effects of 10 cans of Monster, Celsius or Coca cola every day for 13 years would do to your liver? However, the proven harmful effects of these beverages doesn’t result in their ban. Strange right?

How to use Comfrey internally

It’s certainly not a surprise that consuming this plant comes with potential risk. If you are willing to consume it, you must accept those risks.

Now, with this being said, comfrey has been used and consumed for centuries. It has amazing benefits for healing internal issues such as internal bleeding, ulcers, heavy menstrual bleeding, asthma and asthma attacks as well as gallbladder and liver issues like Hepatitis C. It also is used to heal broken bones internally, as well as externally.

The key with comfrey, like most powerful plants, is less, is more. Don’t consume comfrey tea like you would Iced-tea. One to 2 cups daily, during healing time, is more than sufficient. You also don’t want to consume comfrey tea daily, for years on end. Use it as a tool to heal, and only while healing from your ailment. You also can use it as a maintenance for liver or gallbladder issues, consuming a tea here and there, throughout your life.

Another way to consume comfrey, is to eat the leaves! And yes they are edible. In fact, “comfrey fritters” is extremely popular recipe throughout the UK. If you’re interested in making this tasty wild snack yourself, you can find our recipe here.

NEVER EVER consume comfrey root. The roots contain dangerous levels of PAs. Comfrey leaves are the only part of the plant that should ever be used internally. It it is also best to dry the leaves prior to using, which decreases the (PA) levels.

Comfrey Tea (Remedy)

• 1-2 teaspoons dried comfrey leaves (Symphytum officinale)

• 1-2 cups boiling water

1. Add your comfrey leaves to a mug or tea ball strainer and pour your boiling water over top of the leaves.

2. Allow this to steep for about 10 minutes then strain out the leaves. Add honey if desired and enjoy!

Suggested Use

For issues of broken bones, ulcers and menstrual bleeding, drink no more than two cups daily. It is also recommended to start slow and work your way up. One cup may be sufficient for most people.

For chronic conditions like Hep C or gallbladder concerns, consume 1 cup daily until you start to see results. Make sure to listen to your body and stay up to date on enzyme levels, test results, etc. With chronic conditions, it is still good to be monitored by medical professionals or facilities that can provide awareness of your situation like specific testing.

What about children

Again, it is always best to do as much research as possible so that you can make the best informed decision for you and your family.

As for myself and my children, we have all used and consumed comfrey tea. When my middle daughter was about 10, she broke her arm. I gave her a half cup of comfrey tea daily for a few weeks until the bone healed. Now, I’m certainly not recommending that others do the same. This was my personal choice and thankfully there was no harmful consequences. Her bone healed perfectly and she is a healthy teenager at this point. This is where you as a parent, must make your own informed decision.

Depending the size of the child, I would recommend to refrain from using this remedy until about the age of twelve. Even then, administer half the adult dose. And just like with chronic conditions, the same monitoring rules apply. Make sure you are seeing improvement and no negative side effects during use. Speak to your child about how they’re feeling and have them tell you when they feel any changes.

Safety Considerations

In this article, we have gone over several reasons why consuming comfrey can be dangerous, especially for people with liver conditions and compromised immune systems. If you have prior health concerns or you take medications it’s best to refrain from using this plant. For healthy individuals that decide to consume this plant, do it in moderation. Be conscious of your intake and listen to your body.

Make sure you have identified one of the comfrey species with low PAs. Do not consume Russian comfrey, and never ever consume the root from any of the comfrey species. My recommendation is to stick with Symphytum officinale. This is the species we use.

The information shared in this article has been for educational purposes only. Always do your own research to make the best informed decision for yourself, your family and your own health. View our disclaimer here.

Final Thought

Comfrey is an amazing medicine when used properly. Only when it’s abused, is when it becomes dangerous. As long as you treat this plant with respect, and use it wisely, it can become an amazing addition to your healing journey.

Stay Wild

SOURCES BELOW

https://www.sciencedirect.com/science/article/abs/pii/S0165614702021065

https://pmc.ncbi.nlm.nih.gov/articles/PMC5894094

https://eclecticschoolofherbalmedicine.com/wp-content/uploads/2025/03/The-comparative-toxicity-of-a-reduced-crude-comfrey-vs-pure-alkaloid-in-chicks-2.pdf

https://eclecticschoolofherbalmedicine.com/wp-content/uploads/2025/03/comfrey-PAs-2.pdf