The Health Benefits of Lomatium

A Medicinal Herb Used to Treat Chronic Viral and Bacterial Infections

Lomatium (Lomatium dissectum) is a medicinal herb from the Apiaceae botanical family. It is related to many familiar species, such as celery and carrots. There are approximately 75 varieties of lomatium, but the most common and most widely used medicinally is Lomatium dissectum. Other common names for lomatium include Lomatium suksdorfii, fern-leaf biscuitroot, desert parsley, cough root and Indian balsam.

Plants from the Apiaceae family are native to western semi-arid regions of North America. This perennial, flowering plant grows in regions of the great plains, deserts and mountains in the Pacific Northwest. It is considered a very slow-growing. It has a tap root, a large, thick central, root from which other roots sprout laterally. It is also known for its longevity.

The root of lomatium is the part of the plant most commonly used. Native Americans included lomatium root as a regular staple in their diet and used it to treat a wide range of illnesses, including respiratory conditions.

Lomatium is well known for its antibacterial, antiviral and antiseptic properties, and is commonly used to treat conditions such as herpes simplex virus (HSV), which is a common cause of causes cold sores and fever blister, and human papillomavirus (HPV), a viral infection that is spread through skin to skin contact.

Perhaps the most notable historical fact about lomatium is its use in the great influenza pandemic of 1918. Physicians in the United States collaborated with Native American tribes in Nevada, reporting a significantly lower incidence of flu symptoms in the natives who took lomatium (compared to those who did not take the herb).

Health Benefits

Lomatium has been used to treat viruses that develop over a prolonged time span, particularly those that involve suppression of the immune system. It is commonly combined with other herbs believed to help strengthen the body’s immune response. In addition, lomatium has been used to treat gum disease, mouth infections, and vaginal infections. People have used lomatium for:

  • Burns
  • Boils and other skin wounds
  • Joint problems
  • Pain
  • Cough
  • Pneumonia
  • Tuberculosis
  • Viral infections, including colds, cough, and flu
  • Urinary tract infections
  • Chronic viral infections (such as Epstein Barr virus, cytomegalovirus, and herpes)

There has been insufficient medical research data to back up the claims that lomatium can effectively and safely treat any health condition.

How it Works

Lomatium is thought to have several antibacterial, antiviral, and antiseptic properties that work to fight against infection. Antiviral properties of lomatium may result from its strong, bitter, aromatic compounds.

Ichthyotoxic tetronic acids are chemical compounds in lomatium found to be active in fighting microbes (bacteria, fungi, and some viruses). Suksdorfin, a natural coumarin, has been extracted from the fruit of Lomatium suksdorfii. It and other coumarins show some inhibitory effect against HIV, and have the potential to be developed into therapeutic antiviral agents.

Lomatium is also thought to be rich in flavonoids. Flavonoids are a diverse group of plant chemicals called phytonutrients. These vitamin-like substances have been found to slow down the rate of immune system aging, helping to reduce risks of age-related diseases.

Lomatium is said to have stimulating expectorant (the ability to thin and help to bring up mucous and other secretions from the lungs) properties. Expectorants are commonly used to treat respiratory conditions.

More Studies

Limited long-term studies or randomized controlled trials (the gold standard of studies) have been conducted on the efficacy of lomatium and many of those that are published involve preliminary results, examples include:

A study published in the Journal of Applied Microbiology reports: “A Lomatium dissectum root extract completely inhibited the cytopathic [producing injury to living cells] effects of rotavirus.” A rotavirus is a very contagious virus that can cause severe diarrhea.

A 2013 Kansas Journal of Medicine study points out that the evidence of the effectiveness of lomatium for its use in treating influenza, and other viruses (including rotavirus) comes from the “anecdotal experience of its use against influenza, it’s in vitro [outside the body] activity against other viruses such as rotavirus, and the observation that Native American populations using lomatium during the influenza pandemic of 1917–18 had low rates of infection.” The evidence was not gathered from proven clinical research studies.

Several older studies of lomatium that found it could inhibit the effects of various pathogens.

Possible Side Effects

Possible side effects from the use of lomatium include nausea (when taken by mouth), photosensitivity (sensitivity to light) and a severe skin rash or hives. A whole-body allergic reaction may occur on the skin from the use of lomatium which may involve the legs, arms, trunk. and face and may cause itching and swelling. This condition usually subsides on its own in approximately two weeks, but anyone with signs of an allergic reaction should seek the advice of a physician or other health care provider and discontinue use of lomatium right away.  


There is not enough clinical research data to back the safe use of lomatium during pregnancy or breastfeeding, or in infants or children, so it should be avoided in those cases. People with liver disease should also avoid the use of lomatium.

Dosage and Preparation


Dosing routines for lomatium vary widely and can range from 3 to 90 drops by mouth four times per day. The right dose of any herbal supplement is dependent on many factors, including a person’s age, overall health, the condition it’s being used for and more. Always follow the instructions of the naturopath, pharmacist, or other health care provider and read and follow the supplement’s label instructions. 

Although a safe and effective dose of lomatium has not been established and backed by medical research, Phytomed (a New Zealand herbal producer, selling herbal supplements for professional/clinical use) suggests the following dose:

Add 0.7 milliliters (mL) (approximately 14 drops) in 2 ounces of water or juice, two to four times per day, between meals.

Note: Some herbal experts suggest starting at a lower dose and gradually building up to a higher one to avoid side effects (such as the whole-body rash).


Lomatium can be eaten as an unprocessed plant (the roots are the part of the plant that is ingested). It can also be made into a tea or it can be prepared in what is called an “isolate” preparation, meaning that the resin is removed.

Note: It is thought that removing the isolate can decrease the risk of whole-body rash, but this is not backed by clinical research data, according to the 2018 study.

What to Look For

Lomatium foliage looks very similar to a poisonous plant called hemlock (Conium maculatum). Be aware that hemlock has white flowers instead of yellow or purple). The poisonous look-alike also has small purple spots on the stems and leaf stalks, says the U.S. Department of Agriculture Natural Resources Conservation Service Idaho Plant Materials Program.

Like most other medicinal herbs, the best source of lomatium is a wild-crafted product, but the lomatium plant is considered threatened in some areas of the country. It’s important to consult with local experts before harvesting the plant.

Other Questions

Are any other parts of lomatium other than the root used medicinally?

Yes. A tea can be made from the leaves, stems, and flowers.

Is lomatium safe to eat?

No. Although the lomatium root has historically been ingested, the scientific evidence does not back the claims that the plant’s roots can be safely eaten.

A Word from Verywell

Lomatium is one of many medicinal herbs that has a long history of use. Many people, including herbal clinicians and naturopaths, swear by its effectiveness. But there is not enough conclusive clinical research data to scientifically back these claims. This doesn’t mean that the herbal supplement is ineffective, it simply means that there have not been adequate research studies on humans to scientifically prove that it works or that it’s safe for short or long-term use. Just like all other herbal supplements, it’s important to use lomatium only under the supervision of a physician, naturopath, or other health care provider.

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Article Sources

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  1. Garro HA, Pungitore CR. Coumarins as Potential Inhibitors of DNA Polymerases and Reverse Transcriptases. Searching New Antiretroviral and Antitumoral Drugs. Current Drug Discovery Technologies. Volume 12, Issue 2, 2015.

  2. Jassim SAA, Naji MA. Novel antiviral agents: a medicinal plant perspective. Journal of Applied Microbiology. 2003; 95(3):412-427.

  3. Marshall, K., Thornton, S. Worse than the Disease? The Rash of Lomatium Dissectum. Kansas Journal of Medicine; 2018; 11(2): 54–55.

  4. Vanwagenen C, Bradford H, Cardellina II J. Native American Food and Medicinal Plants. Tetrahedron. Volume 42, Issue 4, 1986, pages 1117-1122.

  5. The United States Department of Agriculture Staff. Plant Guide. FERNLEAF BISCUITROOT Lomatium dissectum (Nutt.) Mathias & Constance.

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