Should you Use Medicinal Comfrey?

Comfrey (Symphytum officinale or the Symphytum uplandica x.)  has received bad press in recent years, but it can still be an herbal secret weapon. The trick is in using it with care, somewhat as you would a prescription medication.

Although the entire plant has been used as a remedy since before the Middle Ages, ingesting comfrey is now considered unsafe. It contains potentially toxic pyrrolizidine alkaloids that have been linked to a number of nasty disorders, including cancer and liver damage. It is even considered dangerous to apply comfrey topically to open wounds, or to use it for longer than 10 days in a row, or for long periods, even with breaks in between. The recommendations vary somewhat, but the take away is to use comfrey carefully, only externally, for short periods, and even then only occasionally.

Hmm, sounds scary. Before you set comfrey aside as a bad bargain, though, read on. Allantoin is the beneficial chemical present in comfrey. It's a compound associated with very effective cellular regrowth and repair. Actually, allantoin is used extensively in the cosmeceutical industry today, but that type of allantoin isn't extracted from comfrey. It's produced synthetically.

Recommended Uses for Comfrey

It's considered okay to use comfrey leaves and leaf extracts topically on small areas of unbroken skin. Comfrey will help reduce pain, inflammation and bruising. It will also speed healing.

Here's an example

Condition: You strained your back and have minor but very distracting and inconvenient lower back pain. Not wanting to visit the doctor to get another prescription for an anti-inflammatory, you apply a comfrey ointment or poultice to the area, replacing it every few hours.

Result: The comfrey reduces the swelling which was placing pressure on your nerves, and the pain dissipates to manageable levels. This happens surprisingly quickly.

Conclusions: Should you check with a doctor if you think an injury may be something more than an uncomfortable inconvenience? Definitely.

Should you take care not to overtax your back (or other area of your body) until it's had a chance to heal completely? Absolutely.

The option of having an herbal aid to help you manage the discomfort is pretty empowering, though -- and convenient, too.

More About Comfrey

Historically, one of comfrey's popular common names was "knitbone," a nod to its ability to reduce the discomfort and healing time of conditions like sprains, strains and even broken bones. A simple comfrey poultice or salve can help treat:

  • Lower back discomfort
  • Rheumatoid arthritis
  • Minor sprains and strains
  • Redness
  • Bunions
  • Dry skin
  • Rash
  • Inflammation
  • Bug bites and stings

As with other herbs with a long history of use that somewhat contradicts current scientific thinking, you're likely to find differing, often passionate, points of view about using comfrey. Health food stores, and others still sell comfrey tea, for instance, even though taking it internally is almost universally discouraged today. It's interesting to note that Comfrey products are available in the U.S., but are now banned in Canada, Australia, Germany and a number of other countries.

For practical purposes, use of comfrey is contraindicated if you are currently taking prescription medications (especially those which pose a risk of liver damage if abused), are pregnant, breastfeeding, are treating a young child or the elderly, or currently have liver problems. One major concern is that comfrey could team up with other meds to cause liver damage where one or the other alone would not. As an example, acetaminophen, the main ingredient in pain medications like Tylenol, is one common over-the-counter drug that's contraindicated when using comfrey.

Rather than list all the possible interactions and other cautions, I'll direct you to additional content you may want to review:

If you still feel using comfrey may be right for you, I recommend trying it to treat a minor strain or back pain using a very simple ointment.

Simple Comfrey Ointment

There are lots of ways to use comfrey externally: You can add it to lip balm, make a cream for burns and inflammation or whip together a compress. You can dry it and add it to a DIY tea bag as a mini poultice for a bunion or bee sting. For your first comfrey experiment, though, I'd recommend an ointment. It'll keep a while, and you can try a comfrey cure for a sting, burn or inflammation easily once the concoction is sitting in your fridge ready to go.

Although the best comfrey ointments include other helpful ingredients (like calendula) and often have a smooth consistency, thanks to the addition of beeswax, our simple two ingredient comfrey ointment recipe uses good old petroleum jelly. I recommend it to newbies because it's stable, easy to work with and convenient.

The best recipes are the ones you actually use rather than just peruse, and nothing makes an interesting recipe more doable than having the ingredients on hand. If you find you like like using comfrey, you can move on to other, more ingredient dense preparations later. Consider this a test to see if comfrey lives up to the hype.

This recipe uses dried comfrey. If you don't have any around, you can find it at your local health food store or online.

Simple Comfrey Ointment Recipe


For this one you'll need a double boiler or small crockpot, a couple of heatproof jars, a fine mesh strainer or cheese cloth, petroleum jelly and dried comfrey.



  • 1 ounce comfrey (about 30g)
  • 1 cup petroleum jelly (250g)


  1. Melt petroleum jelly in a small (appetizer sized) slow cooler set on low, or use a double boiler.
  2. Continue heating the ingredients for a couple of hours. If you are using a double boiler, the water should be at or just below a simmer.
  3. Strain the hot oil through a fine mesh strainer or three layers of cheesecloth. (Take care. The oil will be hot and stick anywhere it lands.
  4. While still warm and liquid, pour mixture into heat resistant containers. (I use 4-ounce canning jars if nothing else seems sturdy enough.)

Keep comfrey ointment in your refrigerator. It will stay viable for six months or so. (Be sure to label it for external use only.)

Apply sparingly, and repeat application every few hours. Take for no more than 10 days in a row.

Growing Comfrey

A winter hardy perennial, comfrey is easy to grow. It does prefer rich, moist soil and full sun, and also tends to hog as much space as it can, so it's a good idea to contain it in a large pot buried in the ground. Growing to a height of about three feet, comfrey's large, hairy leaves can become heavy and tip the plant, especially after a rain. Its lavender to cream colored flowers and deep green foliage make it a nice backdrop for shorter herbs and colorful annuals.

Note: Comfrey will often grow in areas where other, more demanding herbs, will not. So, even if it doesn't get the soil conditions it likes, there's a good chance comfrey will still succeed in your garden without much help. People typically have more trouble getting rid of comfrey than getting it to grow in the first place.

Oh, and planting a little comfrey has more than just medicinal merit. Comfrey grows very quickly, producing an abundance of leaves. When turned back into the soil, those nice, fleshy leaves have nitrogen fixing properties and stores of potassium other plants will appreciate. This means comfrey will help reenergize your soil and encourage other plants to grow better.

Photo Credits

 In the Garden - Trish Steel [CC BY-SA 2.0 (], via Wikimedia Commons

Plant Specimen - Kate Jewell [CC BY-SA 2.0 (], via Wikimedia Commons

Leaves - Anne Burgess [CC BY-SA 2.0 (], via Wikimedia Commons

Flowers - Mary and Angus Hogg [CC BY-SA 2.0 (], via Wikimedia Commons Mary and Angus Hogg [CC BY-SA 2.0 (], via Wikimedia Commons


Cold Weather and Your Indoor Herbs (and other plants)

Pundits say every season has its advantages, but I have my doubts. I like a brisk morning as much as the next person, but when I can't get the back door open because of snow drifts, and the car is buried in the driveway, again, and my usually happy indoor chive plants are looking more droopy than sprightly, it's time to say whoa!

When it's cold outside -- really cold -- you probably make sure your pets, automobiles and other treasures are protected from frost, ice, sleet and snow -- oh, oh, snow! Even your precious outdoor plants are probably sleeping under a layer of mulch or snug in some other variety of temperature barrier. Everything may seem safe and secure until the big thaw or breakup. That would be some morning (soon, please) when a warm-ish breeze and weak sunlight will start to work their magic.

While you're checking the insulating strips on your doors, and hoping that slight fogging inside your -- usually largest -- double paned window, is a trick of the light, take a few minutes to check your indoor herbs and other plants.

Winter weather means higher energy bills, and if you don't have a humidifier in your home, that extra, welcome heat can also mean brutally dry conditions for plants. A little extra watering may be in order, as well as some spritzing and an emergency dish of pebbles filled with water. If your plants are stressed, and they probably are, you might see leaves with brown tips or margins. This can mean they're desperate to for humidity, to the point of releasing a little from their leaves to create their own. If their makeshift efforts at environmental management don't work, they may turn yellow or just collapse completely.

Protecting Herbs and Houseplants from Outdoor Air

When outdoor temperatures plummet, you let cold air inside every time you open an exterior door. If that air is in a collision course with one of your houseplants, it can spell disaster. When this is the case, either create a windbreak or move the plant. Most houseplants and many herbs require nearly tropical temperatures. A few blasts of arctic air can kill them -- and that would be a real shame.

Watching Heat Registers

Outdoor air isn't the only problem. Plants located next to heat registers can become overheated, and even crispy, from all the circulating warmth. Move or watched them very (as in very, very) carefully. This sounds like a newbie mistake, but home builders love to put heat registers under windows, the only source of natural light in most homes without skylights.

Managing Window Microclimates

Keeping an herb plant in a sunny window usually pays dividends. The herb is nearby for easy harvesting, and keeping green growing things around is just -- nice. During weather extremes, though, close proximity to a window can be dangerous. Despite advertising to the contrary, heat and cold still seep through closed windows via the action of processes like infiltration. This makes the immediate area around them either hotter or colder than the thermostat indicates -- and sometimes remarkably so. In fact, studies conducted by regional energy companies suggest that up to 25 percent of consumer heating and cooling dollars are spent compensating for heat gain or loss from windows.  

The takeaway here is to make sure houseplants are far enough away from windows to be safe, but still close enough to take advantage of the light windows provide. Exposed (no trees, shrubs or other protection) and windward windows are at the greatest risk for cold penetration, and the directional orientation of the window (north, east, south and west) will play a seasonal role, too.

To get a good idea of the climate you're providing your houseplants, test areas around your windows and   drafts from exterior doors with an instant read thermometer. Do this at different times of day and at night.

You can employ multiple strategies to protect your plants from cold:

  • Close window drapes at night.
  • Make sure plant leaves aren't touching windowpanes.
  • Pull plants back a few inches from cold windows.
  • Consider adding insulation to windows (and doors).
  • Consider installing window film
  • Move plants away from the coldest windows, and double up around warmer windows on a regular rotation so all pots get at least some sunlight.

Other Strategies

  • Consider adding grow lights to your setup, too, and reducing your reliance on windows altogether.
  • Cover plants with clear plastic sheeting or bags for warmth during cold snaps. This is for short periods only, and works best if you can create a tent-like arrangement where the plastic isn't actually touching the plants.
  • Add layers of newsprint to dormant plants you may be overwintering in a garage or shed if you think the temperature in that location will drop below freezing.

You can employ multiple strategies to protect plants from drying heat, too:

  • Humidifiers are pretty inexpensive these days and can be a real boon to indoor plants. They're available as large consoles and also in tiny desktop models designed for personal (or plant) use. Make sure any model you consider has an automatic shutoff in case the water runs dry.
  • Grouping plants works, too. Bring outliers into close proximity to one another, creating groupings of multiple plants. This helps create a microclimate where plants share resources like ambient humidity from their pots, sunlight and gentle air flow.
  • Decorative tabletop fountains can also help contribute humidity to groups of plants.
  • Place a fan in your bathroom to blow steam from your shower or bath out into your rooms. This can be especially effective in a small apartment.
  • Keep a large pot of water simmering on the stove, especially on days when your furnace is cycling constantly.  This actually works pretty well, but does require regular monitoring. (I like to add aromatic ingredient to the water like sliced oranges, star anise, cinnamon sticks, mint leaves, lemon balm and cloves, and set the stove timer so I'm reminded to check the water level every couple of hours.)
  • Keep shallow dishes of water on or near your heat registers. If you don't like leaving the water completely exposed to the air (and your curious and thirsty pets), add sand, marbles or small stones to the dish. This creates weight and stability, and discourages the family dogs and cats from using the dishes as second (or third or fourth) watering holes.
  • Open the door to your dishwasher after it completes a cycle and let the steam vent into your rooms. If your dishwasher has a "dry" cycle, turn it off and air dry your dishes instead.
When you're proactive about plant care, you don't have to worry about damage control later when the sun comes out.