Plant Comparison

Pleurisy Root vs Cowslip

A side-by-side comparison of two medicinal plants — every documented constituent, action, use, safety note and cited source, assembled automatically from the Omnia Sana database.

First plant
Second plant
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Plant APleurisy RootAsclepias tuberosaApocynaceaeFull monograph →
Plant BCowslipPrimula verisPrimulaceaeFull monograph →

At a glance

Pleurisy Root and Cowslip: they share 4 indicated uses (arthritis / joint pain, inflammation (general), respiratory support, …); 1 pharmacological action in common.

Pleurisy RootCowslip
Constituents22
Pharmacological actions33
Indicated uses85
Safety notes22
Cited sources1416
Indicated uses
Only Pleurisy Root
BronchitisCold & fluCoughFever
Shared (4)
Arthritis / joint painInflammation (general)Respiratory supportSkin irritation
Only Cowslip
Insomnia / sleeplessness
Pharmacological actions
Only Pleurisy Root
DiaphoreticExpectorant
Shared (1)
Anti-inflammatory
Only Cowslip
AntioxidantSedative / sleep support

Evidence face-off — shared uses

ConditionPleurisy RootCowslipVerdict
Arthritis / joint pain1/101/10Comparable evidence
Inflammation (general)1/101/10Comparable evidence
Respiratory support1/107/10Stronger for Cowslip
Skin irritation2/101/10Comparable evidence

Evidence scores (1–10) are computed from the tier of each cited source. “Comparable” means the two scores are within one point. Follow a score to its detailed sources.

Key Constituents

Cardiac glycosides (cardenolides such as asclepin, calactin and calotropin)[11, 12]

Heart-active compounds that make dosing and safety critical.

Glycosides
Flavonoids and amino acids[12]

Supporting constituents of the root.

Flavonoids
Triterpene saponins (primulic acid)[9]

Concentrated in the root; responsible for the traditional expectorant (secretolytic) action.

Triterpene saponins
Phenolic glycosides and flavonoids[2, 4]

Found mainly in the flowers and leaves; contribute antioxidant activity.

Phenolic compoundsFlavonoidsGlycosides

Pharmacological Actions

Anti-inflammatory[12]

Anti-inflammatory for lung inflammation (traditional)

Diaphoretic[9, 10, 11, 12]

Diaphoretic - promotes sweating to support feverish illness

Expectorant[9, 10, 11, 12]

Traditional expectorant - helps clear phlegm in chest conditions, bronchitis and pleurisy

Anti-inflammatory[11, 12, 13]
Antioxidant[2, 3, 4, 7, 10, 11, 12, 13]
Sedative / sleep support[11, 12, 13]

Traditional & Indicated Uses

Arthritis / joint pain[12]Traditional · 1/10

inferred from anti-inflammatory action

Evidence: 1
Label: Arthritis / joint pain
Bronchitis[10, 11, 12]Traditional · 1/10

Traditional expectorant - helps clear phlegm in chest conditions, bronchitis and pleurisy

Evidence: 1
Label: Bronchitis
Cold & flu[11, 12]Traditional · 1/10

inferred from diaphoretic action

Evidence: 1
Label: Cold & flu
Cough[11, 12]Traditional · 1/10

inferred from expectorant action

Evidence: 1
Label: Cough
Fever[11, 12]Traditional · 1/10

inferred from diaphoretic action

Evidence: 1
Label: Fever
Inflammation (general)[12]Traditional · 1/10

Anti-inflammatory for lung inflammation (traditional)

Evidence: 1
Label: Inflammation (general)
Respiratory support[9, 10, 11, 12]Traditional · 1/10

inferred from expectorant action

Evidence: 1
Label: Respiratory support
Skin irritation[7, 12]Traditional · 2/10

inferred from anti-inflammatory action

Evidence: 2
Label: Skin irritation
Arthritis / joint pain[11, 12, 13]Traditional · 1/10

inferred from anti-inflammatory action

Evidence: 1
Label: Arthritis / joint pain
Inflammation (general)[11, 12, 13]Traditional · 1/10

inferred from anti-inflammatory action

Evidence: 1
Label: Inflammation (general)
Insomnia / sleeplessness[11, 12, 13]Traditional · 1/10

inferred from sedative action

Evidence: 1
Label: Insomnia / sleeplessness
Respiratory support[1, 2, 5, 9, 11, 12, 13]Good · 7/10
Evidence: 7
Label: Respiratory support
Skin irritation[11, 12, 13]Traditional · 1/10

inferred from anti-inflammatory action

Evidence: 1
Label: Skin irritation

Safety, Cautions & Contraindications

Safety note[8, 11, 12]Caution

Contains cardiac glycosides: do NOT use in pregnancy, breastfeeding or infancy, in anyone with a heart condition, or alongside cardiac glycoside medicines (e.g. digoxin). The plant's cardenolide-rich latex is directly toxic - a documented case caused corneal injury through Na/K-ATPase inhibition.

Safety note[12]Info

Large doses are emetic and purgative (cause vomiting and diarrhoea). There is very little modern safety or efficacy data, so use only under the guidance of a qualified practitioner.

Safety note[11, 12, 13]Caution

Allergy risk: avoid if you’re allergic to cowslip/other Primula species (European Medicines Agency, 2012). Stomach sensitivity: use caution if you have gastritis or a stomach ulcer—cowslip can upset the stomach in some people (European Medicines Agency, 2012). Possible side effects (especially high dose): nausea, vomiting, diarrhea; allergic reactions can happen (European Medicines Agency, 2012). Pregnancy/breastfeeding: not recommended due to lack of good safety data (European Medicines Agency, 2012). Kids: many preparations are not recommended under 12 (and some root extracts under 4) unless a labeled product specifically allows it (European Medicines Agency, 2012).

Safety note[11, 12, 13, 14]Caution

Duke (2002) provides clinical evidence (score 2) for cowslip's expectorant and secretolytic activities, consistent with Commission E approval for bronchitis and cough with mucus. Dose: 0.5–1 g root or 1–2 g herb as tea three times daily. Saponins in the root are responsible for the expectorant action. Duke warns that the plant may cause hemolysis in large doses due to saponin content, and caution is warranted in individuals with aspirin sensitivity due to phenolic acid content (Duke, 2002).

External Ids

Gbif: 3170305
Wikidata: Q311131
Gbif: 8377689
Wikidata: Q157552

Botanical Description

Erect perennial herb with hairy, unbranched stems and narrow, lance-shaped, alternate leaves (unlike most milkweeds, its sap is clear rather than milky). Vivid orange-red flowers are borne in showy, flat-topped umbel-like clusters at the stem tips, making it a prized butterfly and pollinator plant. The stout, fibrous, branching root is the medicinal part.[11]

Height: 30-90 cm
Habit: Erect, hairy perennial herb
Leaves: Narrow, lance-shaped, alternate
Flowers: Vivid orange-red flowers in showy, flat-topped umbel-like clusters
Stem: Erect, hairy, unbranched, exuding clear (not milky) sap when cut
Root: Stout, fibrous, branching taproot
Fruit: Spindle-shaped seed pod (follicle) releasing silky-tufted seeds
Flowering Period: June-September

Low perennial herb (Primulaceae) forming a basal rosette of wrinkled, oval, softly hairy leaves that taper abruptly to a winged stalk. A single leafless flowering stem rises from the rosette bearing a one-sided umbel of small, fragrant, deep yellow, funnel-shaped flowers with orange spots at the throat, nodding on slender pedicels.[10]

Height: Low rosette; flowering stem 10-25 cm
Habit: Low rosette-forming perennial herb
Leaves: Wrinkled, oval, softly hairy, tapering to a winged stalk
Flowers: Small, fragrant, deep yellow, funnel-shaped with orange throat spots, in a one-sided nodding umbel
Stem: Single, leafless flowering stem
Root: Short rhizome with fibrous roots
Fruit: Small capsule
Flowering Period: April-May

Habitat

Native to dry prairies, open fields, roadsides and sandy or rocky open ground across most of eastern and central North America.[11]

Native across Europe and western Asia, growing in unimproved, species-rich grassland, meadows, pastures, open woodland and hedge banks on calcareous or well-drained soils.[10]

Harvesting

The root is dug in autumn after the plant has finished flowering and seeding, then cleaned and dried; given its cardiac glycoside content and near-absence of modern safety data, harvesting and use should only be undertaken with expert guidance.[11]

Parts: Root
Season: Autumn

Flowers are picked in spring as they open; the root/rhizome is dug in autumn.

Parts: Flower, Root/rhizome
Season: Flower in spring; root/rhizome in autumn

Traditional Uses

Pleurisy root has a Native American and Eclectic-medicine reputation, reflected in its name, as an expectorant and diaphoretic for chest complaints, bronchitis and pleurisy, used to promote sweating during feverish illness and help clear phlegm.[11, 12]

Cowslip has a long European folk tradition as an expectorant remedy for coughs and bronchial catarrh, and the flowers have traditionally been used as a mild sedative and for headache. Modern research on its saponin-rich root supports secretolytic (mucus-thinning) expectorant activity, and its flowers are rich in antioxidant phenolics.[1, 6]

Preparations

Decoction[11]

Dried root simmered in water as a traditional expectorant and diaphoretic remedy; given its cardiac glycoside content, only under qualified practitioner guidance.

Root decoction/tea[1]

Dried root simmered or infused, the traditional expectorant preparation for cough with mucus.

Standardised combination extract[1]

Root is a component of some standardised multi-herb bronchial/cough products (e.g. combined with ivy and thyme).

Dosage

All preparations[12]

Because the root contains cardiac glycosides and modern safety/efficacy data are very limited, no general dose is given here; use only under the guidance of a qualified practitioner, and never in pregnancy, breastfeeding, infancy, or with a heart condition or cardiac glycoside medicines. Educational reference only, not a prescription.

Root/herb tea[11, 12, 13]

Duke (2002): about 0.5-1 g root or 1-2 g herb as tea, three times daily. Educational reference only, not a prescription; large doses of the saponin-rich root can cause gastrointestinal upset.

References

REF-0734, REF-0738, REF-0735, REF-1944, REF-1945, REF-1946, REF-1947, REF-0626, REF-1948, REF-1949
REF-0870, REF-0871, REF-0872, REF-0873, REF-0874, REF-0875, REF-0876, REF-0877, REF-0878, REF-0879

Lookalikes Review

Outcome: has-lookalikes
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07
Outcome: none-known
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07

Dangerous Lookalikes

Safety note[13, 14]Dangerous
Dangerous Plant: apocynum-cannabinum
Confused Part: Young shoots (and the root) gathered from the wild; toxic dogbane sends up very similar shoots in the same habitat.
Confusion Context: Butterfly weed / pleurisy root (Asclepias tuberosa) is a milkweed whose young shoots and root have been used. Its main dangerous look-alike is dogbane (Apocynum cannabinum): at the shoot stage the two are easily confused and grow in similar places. Dogbane is a high-severity poison - its milky sap contains cardiac glycosides, all parts are toxic to humans, and poisoning can cause vomiting, weakness and cardiac arrest, while the sap blisters skin. Because the young shoots look alike, the bitterness test below matters.
Distinguishing Features: Taste/bitterness (decisive): dogbane is horribly, intensely bitter - an immediate warning to spit it out; edible milkweed shoots are not. Never swallow a bitter 'milkweed' shoot., Growth habit: dogbane shoots are thinner and firmer and branch early; milkweeds do not branch at the shoot stage. An early-branching, thin, firm shoot is likely dogbane., General: both milkweeds and dogbane have milky sap, so sap alone does not distinguish them - rely on bitterness and branching, and confirm the species before eating.
Key Test: Taste a tiny piece and check the branching (then spit it out). An intensely bitter shoot, or one that is thin, firm and branches early, is dogbane - toxic, do not eat. Milky sap alone does not prove it is safe; if in any doubt, discard it.
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07

Not documented

Drug Class Interactions

Not documented

Safety note[15, 16]Caution
Drug Class: sedatives-cns-depressants
Mechanism: Cowslip is traditionally used as a calming, sedative herb; taken with sedatives, sleeping tablets or other central-nervous-system depressants (including alcohol) it may add to drowsiness and slowed reactions.
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-03

References & Sources

  1. Warashina, T. and Miyase, T (2017) 'New 8,12;8,20-diepoxy-8,14-secopregnane hexa- and hepta-glycosides from the roots of Asclepias tuberosa', Journal of Natural Medicines, 72(1), pp. 347-356. doi:10.1007/s11418-017-1155-9 Preclinical
    https://doi.org/10.1007/s11418-017-1155-9
  2. Abe, F. and Yamauchi, T (2000) 'An androstane bioside and 3'-thiazolidinone derivatives of doubly-linked cardenolide glycosides from the roots of Asclepias tuberosa', Chemical & Pharmaceutical Bulletin, 48(7), pp. 991-993. doi:10.1248/cpb.48.991 Preclinical
    https://doi.org/10.1248/cpb.48.991
  3. Lockwood, T.L (1848) 'Asclepias Tuberosa, Butterfly-Weed, Milk-Weed, Pleurisy Root, White Root', The Medical Examiner (Philadelphia), 4(42), pp. 367-368. Available at: https://pubmed.ncbi.nlm.nih.gov/38120955/ Traditional / reference
    https://pubmed.ncbi.nlm.nih.gov/38120955/
  4. Abe, F. and Yamauchi, T (2000) 'Pregnane glycosides from the roots of Asclepias tuberosa', Chemical & Pharmaceutical Bulletin, 48(7), pp. 1017-1022. doi:10.1248/cpb.48.1017 Preclinical
    https://doi.org/10.1248/cpb.48.1017
  5. Warashina, T. and Noro, T (2009) '8,14-Secopregnane glycosides from the aerial parts of Asclepias tuberosa', Phytochemistry, 70(10), pp. 1294-1304. doi:10.1016/j.phytochem.2009.07.033 Preclinical
    https://doi.org/10.1016/j.phytochem.2009.07.033
  6. Warashina, T. and Noro, T (2010) '8,12;8,20-Diepoxy-8,14-secopregnane glycosides from the aerial parts of Asclepias tuberosa', Chemical & Pharmaceutical Bulletin, 58(2), pp. 172-179. doi:10.1248/cpb.58.172 Preclinical
    https://doi.org/10.1248/cpb.58.172
  7. Warashina, T., Umehara, K., Miyase, T. and Noro, T (2011) '8,12;8,20-diepoxy-8,14-secopregnane glycosides from roots of Asclepias tuberosa and their effect on proliferation of human skin fibroblasts', Phytochemistry, 72(14-15), pp. 1865-1875. doi:10.1016/j.phytochem.2011.05.012 Preclinical
    https://doi.org/10.1016/j.phytochem.2011.05.012
  8. Mikkelsen, L.H., Hamoudi, H., Gul, C.A. and Heegaard, S (2017) 'Corneal Toxicity Following Exposure to Asclepias Tuberosa', The Open Ophthalmology Journal, pp. 1--4. doi:10.2174/1874364101711010001 Preclinical
    https://doi.org/10.2174/1874364101711010001
  9. Lockwood, T.L (1848) 'Asclepias Tuberosa, Butterfly-Weed, Milk-Weed, Pleurisy Root, White Root', Medical Examiner (Philadelphia), 4(42), pp. 367-368. Traditional / reference
    https://scholar.google.com/scholar?q=Asclepias%20Tuberosa%2C%20Butterfly-Weed%2C%20Milk-Weed%2C%20Pleurisy%20Root%2C%20White%20Root
  10. Lockwood, T.T (1848) 'Asclepias Tuberosa, Butter-Fly-Weed, Milk Weed, Pleurisy Root, White Root', Buffalo Medical Journal and Monthly Review, 3(10), pp. 600-602. Traditional / reference
    https://scholar.google.com/scholar?q=Asclepias%20Tuberosa%2C%20Butter-Fly-Weed%2C%20Milk%20Weed%2C%20Pleurisy%20Root%2C%20White%20Root
  11. The Naturopathic Herbalist (n.d.) 'Asclepias tuberosa'. Available at: https://thenaturopathicherbalist.com/2015/09/06/asclepius-tuberosa/ Traditional / reference
    https://thenaturopathicherbalist.com/2015/09/06/asclepius-tuberosa/
  12. Herbs2000 (n.d.) 'Pleurisy Root (Asclepias tuberosa)'. Available at: https://www.herbs2000.com/herbs/herbs_pleurisy_root.htm Traditional / reference
    https://www.herbs2000.com/herbs/herbs_pleurisy_root.htm
  13. Forager Chef 'Foraging and Cooking Milkweed'. Available at: https://foragerchef.com/guide-to-milkweed/ Traditional / reference
    https://foragerchef.com/guide-to-milkweed/
  14. North Carolina Extension Gardener Plant Toolbox 'Apocynum cannabinum (Dogbane)'. Available at: https://plants.ces.ncsu.edu/plants/apocynum-cannabinum/ Traditional / reference
    https://plants.ces.ncsu.edu/plants/apocynum-cannabinum/
  1. Veldman, J., Bordewijk, E., Lloyd, A.R., Vlieger, A.M. and others (2023) 'Mechanistic Evidence of Andrographis paniculata, Pelargonium sidoides, Echinacea Species and a Combination of Hedera helix, Primula veris/elatior and Thymus vulgaris/zygis in the Treatment of Acute, Uncomplicated Respiratory Tract Infections: A Systematic Literature Review and Expert Interviews', Pharmaceuticals (Basel), 16(9), pp. 1206. doi:10.3390/ph16091206 Meta-analysis / review
    https://doi.org/10.3390/ph16091206
  2. Baczek, K.B., Kosakowska, O., Przybyl, J.L., Pioro-Jabrucka, E. and others (2017) 'Phenolics in Primula veris L. and Primula elatior (L.) Hill Raw Materials', International Journal of Analytical Chemistry, 2017, pp. 2871579. doi:10.1155/2017/2871579 Preclinical
    https://doi.org/10.1155/2017/2871579
  3. Prokofiev, A.B., Latypova, G.M., Bondarenko, T.A., Romanenko, E.B. and others (2023) 'Solid herbal extract of Primula veris L. improves morphofunctional condition of rats' myocardium in chronic alcohol intoxication', Journal of Traditional and Complementary Medicine, 13(3), pp. 306-314. doi:10.1016/j.jtcme.2023.02.006 Preclinical
    https://doi.org/10.1016/j.jtcme.2023.02.006
  4. Tarapatskyy, M., Gumienna, A., Sowa, P., Kapusta, I. and Puchalski, C (2021) 'Bioactive Phenolic Compounds from Primula veris L.: Influence of the Extraction Conditions and Purification', Molecules, 26(4), pp. 997. doi:10.3390/molecules26040997 Preclinical
    https://doi.org/10.3390/molecules26040997
  5. Trendafilova, A., Ivanova, V., Todorova, M., Aneva, I. and others (2025) 'Phytochemical Characterization and Anti-Biofilm Activity of Primula veris L. Roots', Molecules, 30(8), pp. 1702. doi:10.3390/molecules30081702 Preclinical
    https://doi.org/10.3390/molecules30081702
  6. Colombo, P.S., Flamini, G., Rodondi, G., Giuliani, C. and others (2017) 'Phytochemistry of European Primula species', Phytochemistry, 143, pp. 132-144. doi:10.1016/j.phytochem.2017.07.005 Traditional / reference
    https://doi.org/10.1016/j.phytochem.2017.07.005
  7. Latypova, G.M., Bondarenko, T.A., Katayev, V.A., Romanenko, E.B. and others (2019) 'Composition and cardioprotective effects of Primula veris L. solid herbal extract in experimental chronic heart failure', Phytomedicine, 54, pp. 17-26. doi:10.1016/j.phymed.2018.09.015 Preclinical
    https://doi.org/10.1016/j.phymed.2018.09.015
  8. Brys, R. and Jacquemyn, H (2015) 'Disruption of the distylous syndrome in Primula veris', Annals of Botany, 115(1), pp. 27-39. doi:10.1093/aob/mcu211 Preclinical
    https://doi.org/10.1093/aob/mcu211
  9. Muller, A., Ganzera, M. and Stuppner, H (2006) 'Analysis of phenolic glycosides and saponins in Primula elatior and Primula veris (primula root) by liquid chromatography, evaporative light scattering detection and mass spectrometry', Journal of Chromatography A, 1112(1-2), pp. 218-223. doi:10.1016/j.chroma.2005.10.067 Preclinical
    https://doi.org/10.1016/j.chroma.2005.10.067
  10. Graikou, K., Damianakos, H., Ganos, C., Syklowska-Baranek, K. and others (2023) 'Comparative Phytochemical Analyses of Flowers from Primula veris subsp. veris Growing Wild and from Ex Situ Cultivation in Greece', Foods, 12(13), pp. 2623. doi:10.3390/foods12132623 Preclinical
    https://doi.org/10.3390/foods12132623
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  12. Royal Botanic Gardens, Kew (n.d.). Available at: https://powo.science.kew.org Traditional / reference
    https://powo.science.kew.org
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  15. Ghasemzadeh Rahbardar, M. and Hosseinzadeh, H (2024) 'Therapeutic potential of hypnotic herbal medicines: A comprehensive review', Phytotherapy Research, 38(6), pp. 3037-3059. doi:10.1002/ptr.8201 Meta-analysis / review
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Generated automatically from the Omnia Sana plant database and its cited sources. For educational purposes only — not medical advice. Always consult a qualified practitioner before using medicinal plants.