Pelargonium sidoides, the South African root sold as umckaloabo, its tannins and coumarins, the EPs 7630 extract, and what an independent trial found when it was tested against usual care.

The episode reads the Institute's 2026 Journal article. P. sidoides is a low, silver-leaved geranium of the summer-rainfall grasslands of the Eastern Cape and Lesotho, with a tuberous rootstock that carries it through frost, drought and fire; digging it kills the plant. Charles Henry Stevens brought a root decoction to Britain in 1897 and sold it without naming the plant. Adrien Sechehaye's Geneva case series of about 800 tuberculosis patients followed in the 1920s, and the source species, with P. reniforme alongside it, was identified in Munich in 1977. In 2010 the European Patent Office revoked Willmar Schwabe's extraction patent after oppositions that included the Masakhane community of the Tyhume Valley and the African Centre for Biosafety. It fell on lack of inventive step, so the benefit-sharing question went undecided.

The Cochrane review (2008, updated 2013) graded the evidence for EPs 7630, an 11% ethanol liquid, as low quality in acute bronchitis and very low in sinusitis and the common cold, citing likely publication bias and manufacturer-sponsored trials; tablets did less well than the liquid. A 2026 open-label trial of 332 adults in Swiss primary care found no significant difference against usual care in time to halve symptom severity, with a trend to less antibiotic use, 17.4% against 25.2%. The last third covers red-flag symptoms and the one-week rule, the German liver warnings and the CIOMS reassessments in which none of 28 cases reached probable causality, its AUST R registration, the 2011 advisory committee minutes on a non-specific polyphenol assay, and what to check on the box.

In this episode: (00:00) A brown bottle in the winter pharmacy aisle; (01:43) The article and its contradictions; (04:04) A geranium in witness protection; (05:40) Grasslands, frost and a 2,300 m range; (07:00) The tuber that survives fire; (07:42) Traditional use and the name umckaloabo; (08:40) Charles Henry Stevens and tuberculosis, 1897; (10:57) Sechehaye's 800 Geneva cases; (12:41) The plant is named in 1977; (13:51) Harvest kills the plant; (14:33) The Schwabe extraction patent; (15:39) The Masakhane community goes to Munich; (17:09) Revoked on inventive step; (18:42) Nagoya and provenance; (19:46) Wild harvest and cultivation; (21:07) Tannins and the pharmacopoeia standard; (22:44) Coumarins as the fingerprint; (23:26) Why these coumarins do not thin the blood; (25:40) In vitro against in vivo; (28:36) The Cochrane review and EPs 7630; (30:20) Low-quality evidence and sponsored trials; (31:11) Liquid against tablet; (32:27) The HATRIC feasibility study; (33:07) The 2026 Swiss primary care trial; (34:34) Fewer antibiotics?; (36:43) Red flags and the one-week rule; (38:35) Masking tuberculosis; (39:03) Side effects and allergy; (39:27) The German liver warnings; (39:54) Reassessing causality; (41:30) Why the warning stays; (42:16) Nose and gum bleeding; (43:41) How it reached Australian shelves: AUST R; (44:46) Export-only listings; (45:20) The 2011 committee minutes; (47:52) Has the evidence changed?; (49:15) What to check on the box; (51:13) Closing thought.

Read more in the Institute's Journal: https://www.australian-pharmacognosy.org/blog/umckaloabo-pelargonium-sidoides-evidence-review/

Nothing in this episode is a prescription or a dose. If you want to use a herb, consult a degree-qualified herbalist with competencies and adequate training in pharmacognosy.

Dr Luke Iggulden, Chief Scientific Officer, made the episode from the Institute's Journal and monograph material. Jesse Kirby, Head of Community Outreach, wrote the show notes and chapters from the episode transcript.

The Herbarium Hour, from the Australian Institute of Pharmacognosy, Cardwell, Queensland.