ISO 20255:2026

• Abstract:

  This document specifies the minimum requirements and test methods for wild and cultivated Epimedium herb. This document applies to Epimedium herb that is sold and used as natural medicines in international trade, including Chinese materia medica (whole medicinal materials) and decoction pieces derived from this plant.

• Status: Published
• Publication Date: 27-Sep-2026
• ICS: 11.120.10 - Medicaments
• Technical Committee: ISO/TC 249 - Traditional Chinese medicine
• Drafting Committee: ISO/TC 249 - Traditional Chinese medicine
• Current Stage: 6060 - International Standard published
• Start Date: 28-Sep-2026
• Due Date: 01-Mar-2027
• Completion Date: 28-Sep-2026

Overview

ISO 20255:2026 is an International Standard for Traditional Chinese medicine that covers Epimedium brevicornu, Epimedium sagittatum, Epimedium pubescens, and Epimedium koreanum herb. It specifies minimum requirements and test methods for wild and cultivated Epimedium herb used in international trade.

This standard is relevant for products sold and used as natural medicines, including:

• Chinese materia medica as whole medicinal materials
• Decoction pieces derived from Epimedium species

By setting clear quality expectations, ISO 20255:2026 supports more consistent identification, safer handling, and improved market confidence in Epimedium herb quality control.

Key Topics

The standard focuses on practical requirements for inspection, authentication, and quality assurance of Epimedium raw materials and processed medicinal products. Key areas include:

• Botanical scope

  • Covers four Epimedium species used in traditional Chinese medicine
  • Applies to both wild and cultivated sources

• General characteristics

  • Requires material to be clean and free from stem and foreign matter
  • Prohibits visible moldy leaves, external contaminants, and living insects

• Identification and authentication

  • Includes macroscopic identification
  • Includes microscopic identification
  • Uses thin-layer chromatogram (TLC) identification for product verification

• Quality and safety parameters

  • Moisture
  • Total ash
  • Ethanol-soluble extractives
  • Marker compounds
  • Heavy metals
  • Pesticide residues
  • Foreign matter

• Supporting guidance

  • Sampling instructions
  • Test reporting requirements
  • Packaging, storage, transportation, marking, and labelling

The document also includes informative annexes that support TLC identification, marker compounds determination, and reference information on national and regional requirements.

Applications

ISO 20255:2026 is valuable across the herbal medicine supply chain and can be used by:

• Manufacturers of traditional Chinese medicine products
• Quality control laboratories
• Importers and exporters of medicinal plant materials
• Suppliers of wild and cultivated Epimedium herb
• Regulatory and conformity assessment bodies
• Procurement teams sourcing standardized herbal raw materials

Typical use cases include:

• Verifying identity of Epimedium herbal raw material
• Checking compliance before international trade
• Supporting batch release and incoming inspection
• Aligning product quality expectations across markets
• Improving traceability for Chinese materia medica and decoction pieces

For organizations working with Epimedium herb standards, this document helps reduce ambiguity in quality assessment and promotes more reliable trade practices.

Related Standards

ISO 20255:2026 is part of a broader ISO framework for traditional Chinese medicine and herbal raw materials. Related standards referenced in the document include:

• ISO 18664 - Determination of heavy metals in herbal medicines used in Traditional Chinese Medicine
• ISO 21310 - Microscopic examination of medicinal herbs
• ISO 21371 - Labelling requirements of products intended for oral or topical use
• ISO 22217 - Storage requirements for raw materials and decoction pieces
• ISO 22258 - Determination of pesticide residues in natural products by gas chromatography
• ISO 23723 - General requirements for herbal raw material and materia medica

Together, these standards support consistent traditional Chinese medicine quality assurance, safer herbal supply chains, and improved international trade compliance.

International
Standard
ISO 20255
First edition
Traditional Chinese medicine —
2026-09
Epimedium brevicorum, Epimedium
sagittatum, Epimedium pubescens,
and Epimedium koreanum herb
Médecine traditionnelle chinoise — Plantes Epimedium
brevicorum, Epimedium sagittatum, Epimedium pubescens et
Epimedium koreanum
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Descriptions . 2
4.1 Epimedium brevicornu Maxim. .2
4.2 Epimedium sagittatum (Sieb.et Zucc.) Maxim. .2
4.3 Epimedium pubescens Maxim. .2
4.4 Epimedium koreanum Nakai .2
5 Requirements and recommendations . 7
5.1 General characteristics .7
5.2 Microscopic characteristics .7
5.3 Moisture .9
5.4 Total ash .9
5.5 Ethanol-soluble extractives .9
5.6 Thin-layer chromatogram (TLC) identification .9
5.7 Marker compounds .9
5.8 Heavy metals .9
5.9 Pesticide residues .9
5.10 Foreign matter .9
6 Sampling . 9
7 Test methods . 10
7.1 Macroscopic identification .10
7.2 Microscopic identification .10
7.3 Determination of moisture .10
7.4 Determination of total ash .10
7.5 Determination of ethanol-soluble extractives .10
7.6 Thin-layer chromatogram identification .10
7.7 Determination of marker compounds .10
7.8 Determination of heavy metals .10
7.9 Determination of pesticide residues .10
8 Test report .10
9 Packaging, storage and transportation .11
10 Marking and labelling .11
Annex A (informative) Thin-layer chromatogram (TLC) identification .12
Annex B (informative) Determination of marker compounds .15
Annex C (informative) Reference information of national and regional requirements on
Epimedium herb . 17
Bibliography . 19

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
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with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
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This document was prepared by Technical Committee ISO/TC 249/SC 1, Traditional medicine, Subcommittee
SC 1, Traditional Chinese medicine.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
The genus Epimedium belongs to the family Berberidaceae. It has more than 50 species, distributed in North
Africa, northern Italy to the Black Sea, Western Himalayas, Northeast Asia including Korea, Japan, and
part of China. Epimedium is a typical forest plant. In nature, plants of this genus form dense thickets and
bloom on humus-rich, slightly moist soil under the canopy of foothill forests, where the young foliage fully
obscure the sun. They are not tolerant direct sunlight, especially in hot summer. Even in the spring, except
in the morning and evening, their leaves can get burned when exposed to direct sunlight. Therefore, when
planting Epimedium, it is desirable to create the conditions similar to their natural habitat and to place them
in the shade or partial shade from tall trees and shrubs. China is the geographical distribution centre of
Epimedium, where nearly 40 species are found, comprising over 80 % of the genus.
In China, Epimedium herb (known as “Yin Yang Huo”) mainly includes four species, Epimedium brevicornu
Maxim., Epimedium sagittatum (Sieb.et Zucc.) Maxim., Epimedium pubescens Maxim. and Epimedium koreanum
Nakai. Epimedium koreanum Nakai is also distributed in North Korea, Japan, Russia, and Italy.
Modern pharmacological studies show that Epimedium herb has various bioactivities, including anti-
aging, antitumor, anti-depression and anti-osteoporosis effects. It can also enhance immunity, promote
hematopoiesis, increase cardiovascular flow, and regulate bone metabolism.
As national implementation can differ, national standards bodies are invited to modify the values given in
5.3, 5.4 and 5.5 in their national standards. Examples of national and regional values are given in Annex C.

v
International Standard ISO 20255:2026(en)
Traditional Chinese medicine — Epimedium brevicorum,
Epimedium sagittatum, Epimedium pubescens, and Epimedium
koreanum herb
1 Scope
This document specifies the minimum requirements and test methods for wild and cultivated Epimedium
herb.
This document applies to Epimedium herb that is sold and used as natural medicines in international trade,
including Chinese materia medica (whole medicinal materials) and decoction pieces derived from this plant.
2 Normative references
The following documents are referred to in the text in such a way that some or all their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 18664, Traditional Chinese Medicine — Determination of heavy metals in herbal medicines used in
Traditional Chinese Medicine
ISO 21310, Traditional Chinese medicine — Microscopic examination of medicinal herbs
ISO 21371, Traditional Chinese medicine — Labelling requirements of products intended for oral or topical use
ISO 22217, Traditional Chinese medicine —Storage requirements for raw materials and decoction pieces
ISO 22258, Traditional Chinese medicine — Determination of pesticide residues in natural products by gas
chromatography
ISO 23723, Traditional Chinese medicine — General requirements for herbal raw material and materia medica
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
Epimedium herb
terrestrial part or leaves of Epimedium brevicornu Maxim., Epimedium sagittatum (Sieb.et Zucc.) Maxim.,
Epimedium pubescens Maxim., and Epimedium koreanum Nakai (Fam. Berberidaceae)

4 Descriptions
4.1 Epimedium brevicornu Maxim.
Leaf of Epimedium brevicornu is ternately compound. Leaflets are oval in shape, 3 cm to 8 cm in length and
2 cm to 6 cm in width. The apex of leaflet is acuminate. The terminal leaflet is cordate at the base. Bilateral
leaflets are small and oblique cordate. The outer side of the leaf is large and auriculate. The margin of the
leaf is yellow and thorny serrulation. (see Figure 1 A).
The upper surface of the leaflet is yellowish-green, and the lower surface is greyish-green. There are 7 to 9
main veins, with sparsely covering slender hairs at the base. Both surfaces have prominent secondary thin
veins and distinct, reticulated veins. The petiolule is 1 cm to 5 cm in length. The texture is close to leathery.
It has a slight characteristic odour and a slightly bitter taste.
4.2 Epimedium sagittatum (Sieb.et Zucc.) Maxim.
Leaf of Epimedium sagittatum is ternately compound. Leaflets are ternately compound, long-ovoid to ovoid-
lanceolate, 4 cm to 12 cm in length, 2,5 cm to 5 cm in width, with acuminate apices. Bilateral leaflets are
distinctly oblique at the base and their outer sides are mostly arrow-shaped. The lower surface of the leaf
lamina is sparsely covered with thick, short pronated hairs or nearly glabrous. The lamina is leathery (see
Figure 2A).
4.3 Epimedium pubescens Maxim.
Leaf of Epimedium pubescens is ternately compound. The leaflets are 3 to 20 cm in length and 2 cm to 8 cm
in width. The upper surface of the leaflet is dark green to brownish-green and glabrous, with a papery and
coriaceous texture. The lower surface of the leaflet is pale green to greenish-grey. The petioles are densely
covered with flossy pubescence. The lamina of the leaflet is ovate or narrowly ovate to lanceolate with a
serrulate, spiny margin. The apex of the leaflet is acuminate or shortly acuminate. (see Figure 3 A).
4.4 Epimedium koreanum Nakai
Leaf of Epimedium koreanum is ternately compound. Leaflets are relatively large, 4 cm to 10 cm in length,
3,5 cm to 7 cm in width. The upper surface of the leaflet is dark green with
...