Part 5 of 6 in the "Chinese herb risks and checkpoints" series. The list of the other five is at the foot of this part.

The third of the three checks on that packet of 凉茶 ingredients in part 1 was "it has been stored properly throughout". This part is about that one: in weather like Malaysia's, what herbs are vulnerable to, and how "too long" is counted.

The short version

• Hong Kong's Chinese Medicine Regulatory Office states that damage by rodents, insects or micro-organisms, and temperature, humidity and sunlight, all affect the quality of herbs.
• The same guidance gives three reasons why humidity is the key one: mould, the herb's own enzymes hydrolysing its glycosides so their content falls, and volatile oils changing over time.
• The article states only that the content falls; "it may look fine" is our own reading — so "it looks all right" is not a check.
• There is no single number of days for "too long". If you cannot say when a packet was bought, treat it as too long; mould, insect damage or an off-smell means the whole packet goes.

First, the things that cannot wait

⚠️ A safety note: TCM and Western medicine complement each other; it is not a choice between them. If you experience a severe allergic reaction (such as difficulty breathing or facial swelling) or loss of consciousness after taking herbs, call 999 now, or go to the nearest hospital emergency department.

Who needs extra care, what to do first if you feel unwell, and the reason behind each item are in part 6.

A note: this section is general information only. For conditions like these, follow your doctor's diagnosis and treatment, and seek medical attention when you need it.

I. Why humidity is the key

Hong Kong's Chinese Medicine Regulatory Office explains: damage by rodents, insects or micro-organisms, and temperature, humidity and sunlight, all affect the quality of herbs.

The same article continues: in general, processed herbs should be stored in a cool, dry place, for example honey-fried herbs should be refrigerated to prevent mould; aromatic herbs contain volatile oils and should not be stored for long; and in general, herbs that have been stored too long should not be used.

Three reasons, all in that one article.

First, mould: micro-organisms are on its list of damaging factors, and its example is that honey-fried herbs should be refrigerated to prevent mould.

Second, the herb's own enzymes. The article states that herbs containing glycosides also contain an enzyme able to hydrolyse those glycosides, and that under a certain humidity and temperature the enzyme breaks the glycoside constituents down, lowering their content. In plain terms: a packet that has taken in moisture may look fine on the outside, yet its constituents may already be reduced — the "may look fine" is our phrasing; what the article states is that the content falls.

Third, volatile oils. Aromatic herbs contain volatile aromatic oils and should not be stored for long. Time changes what is in a herb: the article's example is 陈皮 (aged tangerine peel), where after a period of storage the volatile-oil content falls and the hesperidin, which the article names as chiefly responsible for its effect, rises in relative terms, which is why earlier generations held that 陈皮 should be used aged; but in general, herbs stored too long should not be used.

II. Bringing those sentences into a Malaysian home

The five rules below are our practice, not the Hong Kong article's wording — the article gives principles, and this is how they land in this weather.

• Sealed, away from light and heat. Move an opened packet into a sealed jar or zip bag and keep it somewhere cool; not next to the stove, not in the car.
• Watch the moisture from air-conditioned rooms. Carried in and out of an air-conditioned room, packaging sweats on the outside, and moisture that reaches the herbs makes them damp. Keep it in one place; do not move it back and forth.
• Honey-fried and oily herbs go in the fridge. For example, anything labelled 蜜炙 or sticky to the touch. The oily-herb rule is our own practice; Hong Kong's guidance mentions honey-fried herbs only.
• Three discard signals: mould, insect damage, off-smell. Any one of them means the whole packet goes. Do not wash or sun-dry it and use it anyway.
• The same goes for 凉茶 ingredients. They are a combination of herbs, so the storage rules are the same. As for drinking it, TCM theory holds that 凉茶 is cooling in nature and is not for drinking daily in place of water; details in "Is Daily Herbal Tea Harmful?" (/is-daily-herbal-tea-harmful/).

Three common scenes, too:

• Packets weighed out at a medical hall, confinement (坐月子) packs: no MAL number is normal (part 3). Ask the shop what situation the packet was composed for, and store it by the five rules above.
• A cup from the 凉茶 shop, canned 凉茶: drink a fresh brew the same day; read the nutrition label on a can. Whether to drink it daily is in part 4.
• Air-conditioned rooms and cars: neither is a place to keep herbs. Keep them in one cool spot at home and carry only the day's portion.

The words in this part

All four are written into that article, and all four are things you may hear at a medical hall or read on a prescription.

• 陈皮 (橘皮, aged tangerine peel) — the article's words: 橘皮, also called 「陈皮」. It is the example the article uses for "time changes what is in a herb".
• Hesperidin (橙皮苷) — the article names it as the constituent chiefly responsible for 陈皮's effect; after a period of storage, as the volatile-oil content falls, its content rises in relative terms.
• Volatile aromatic oil (挥发性芳香油) — the article states that aromatic herbs generally contain volatile aromatic oils, which is why they should not be stored for long. The ones you can smell are usually in this group.
• Hydrolysis (水解) — the word the article uses to explain humidity: under a certain humidity and temperature, the enzyme causes hydrolysis of the glycoside constituents, lowering their content.

Frequently asked

How long can Chinese herbs be kept? There is no single number of days. Hong Kong's Chinese Medicine Regulatory Office says that in general herbs stored too long should not be used; aromatic herbs should not be stored for long; for example, honey-fried herbs should be refrigerated to prevent mould. For packaged proprietary medicine, go by the expiry date on the label. For loose herbs, watch for three signals: mould, insect damage, off-smell; any one of them means discard.

Can mouldy herbs be washed or sun-dried and still used? Our practice is no. The Hong Kong article lists damage by micro-organisms among the factors affecting quality, and says nothing about what washing or drying recovers — what it says is that such herbs should not be used. So this one is handled as "the whole packet goes", not as "treat it and carry on".

Do not: decide whether to keep a packet on the basis that it "still looks all right". The enzyme explanation in section I is precisely the case where the look and the constituents can disagree.

The other five parts

• Part 1: Do Chinese herbs carry risks? Which class has the record, and how Malaysia regulates it
• Part 2: The class with the record: what the record says, and why registration screening catches it
• Part 3: Can I take what I bought? Reading and checking the MAL number and Meditag
• Part 4: One table: what you are holding, and how to check it
• Part 6: Situations that need extra care — who asks a doctor and a practitioner first, and what to do if you feel unwell

👉 If you are unsure whether "this packet of herbs, or this bottle of proprietary medicine in my hand, is actually right for me to use", you are welcome to book an online consultation with HansMed, where a practitioner registered under the T&CM Act 2016 assesses it with you.

Sit with a licensed TCM practitioner from wherever you are.

HansMed Modern TCM

Sources

• Chinese Medicine Regulatory Office, Department of Health, Hong Kong, feature article on general knowledge of taking Chinese medicines, dietary precautions and storage methods — https://www.cmro.gov.hk/files/gb/useful_information/public_health/feature_articles/Knowledge_of_Taking_Chinese_Medicines_Precautions_and_Storage_Method.pdf

本文是「中药的风险与把关」系列的第 5 篇，共 6 篇。另外五篇的清单在文末。

第 1 篇开头那包凉茶料，答案的第三样是「一直存放得当」。这一篇讲那一样：在马来西亚这种天气里，药材怕的是什么，以及「放太久」怎么算。

一分钟看完

• 香港卫生署中医药规管办公室写明：鼠害、虫害或微生物的破坏、温度、湿度及日光照射，都会影响中药材的品质。
• 湿度之所以是关键，同一份说明给了三个原因：霉变、药材自己的酶让苷类水解（成分含量降低）、以及挥发油随时间改变。
• 同一份说明只写成分含量降低；「外表看不出」是我们的推论——所以「看起来没事」不是一个检查。
• 「放太久」没有统一的天数。 说不出这包药是什么时候买的，就按「过久」处理；霉点、虫蛀、异味，有一样就整包丢。

先说不能等的几件事

⚠️ 安全提醒：中医与西医是互相补位的关系，不是二选一。服用中药后若出现严重的过敏反应（如呼吸急促、脸部肿胀）或意识不清，请立刻拨打 999，或前往最近的医院急诊部。

哪些人要特别小心、不舒服时该先做什么、每一项的理由，见第 6 篇。

小提醒：本段仅为一般知识说明。相关情况请以西医的诊断与治疗为主，并在需要时及时就医。

一、为什么湿度是关键

香港卫生署中医药规管办公室的说明：鼠害、虫害或微生物的破坏、温度、湿度及日光照射，都会影响中药材的品质。

同一份说明接着写：一般而言，经炮制的中药材应储存于阴凉干燥处，例如经蜜炙的药物宜冷藏，免生霉变；芳香的药材含挥发性芳香油，不宜长时间储存；一般情况下，药物不宜选用存放过久的。

三个原因，都在同一份说明里。

一是霉变。它列出的破坏因素里有微生物，给的例子是经蜜炙的药物宜冷藏、免生霉变。

二是药材自己的酶。说明写：含苷类的药，同时都含有能够让苷类水解的一种酶类，在一定的湿度和温度下，酶类会造成苷类化学成分的水解，使它的含量降低。换句话说，受了潮的药材外表可能看不出，成分含量却可能已经降低——这句「看不出」是我们的说法，说明本身只写含量降低。

三是挥发油。芳香的药材含挥发性芳香油，不宜长时间储存。时间会改变药材的成分：说明举的例子是陈皮，存放一段时间后挥发油含量降低，它所说起主要药效的橙皮苷含量相对增高，前人因此认为陈皮宜用陈久的；但一般情况下，药物不宜选用存放过久的。

二、把这几句放进马来西亚的家里

下面五条是我们的做法，不是香港那份说明的原话——说明讲的是原则，这里讲的是在这种天气里怎么落地。

• 密封、避光、避热。 拆开的药包换到密封罐或夹链袋，放阴凉处；不放炉灶旁，不放车里。
• 留意冷气房的水气。 从冷气房拿进拿出，包装外面会结露，水气进了药材就容易受潮。放定一个地方，不要来回搬。
• 蜜炙类、含油脂的药材，冷藏。 例如标签写「蜜炙」或摸起来黏手的那几味。含油脂这一条是我们自己的做法，香港的说明只提到蜜炙。
• 三个丢弃信号：霉点、虫蛀、异味。 有一样就整包丢，不清洗、不晒过再用。
• 凉茶料也一样。 它是药材的组合，存放规则相同。至于喝，中医理论认为凉茶性寒，不宜当水天天喝；细节见〈凉茶天天喝会伤身吗〉（/is-daily-herbal-tea-harmful/）。

还有三种常见的场面：

• 药材铺秤的药包、坐月子药包：没有 MAL 编号是正常的（第 3 篇）。问店家这包是给什么情况配的，回家按上面那五条存放。
• 凉茶铺的一杯、罐装凉茶：现煮的当天喝完；罐装的看营养标签。天天喝不喝，见第 4 篇。
• 冷气房、车里：都不是放药材的地方。药材放定家里阴凉的一格，随身只带当天的份。

这篇出现的几个词

四个都写在那份说明里，也都是您在药材铺听得到、在药方上看得到的说法。

• 陈皮（橘皮，aged tangerine peel）——说明写：橘皮，又名「陈皮」。它是这份说明用来讲「时间会改变成分」的那个例子。
• 橙皮苷（hesperidin）——说明把它称作陈皮里「起主要药效」的成分；存放一段时间后，当挥发油含量降低时，它的含量相对增高。
• 挥发油（挥发性芳香油，volatile aromatic oil）——说明写：芳香的药材一般都含有挥发性的芳香油，所以不宜长时间储存。闻得到香气的那几味，多半就是这一类。
• 水解（hydrolysis）——说明用来解释湿度的词：在一定的湿度和温度下，酶类会造成苷类化学成分的水解，使它的含量降低。

常见问题

中药可以放多久？ 没有统一的天数。香港卫生署中医药规管办公室的说明是：一般情况下，药物不宜选用存放过久的；芳香的药材不宜长时间储存；例如经蜜炙的宜冷藏，免生霉变。包装中成药看标签上的有效期限。散装药材看三个信号：霉点、虫蛀、异味，有一样就丢。

发霉的药材洗一洗、晒一晒还能用吗？ 我们的做法是不用。香港那份说明把微生物的破坏列在影响品质的因素里，并没有写清洗或晾晒能挽回什么——它写的是「不宜选用」。所以这一条按整包丢处理，不按「处理一下再用」处理。

不要这样做： 不要靠「看起来还好」来决定一包药材留不留。上面第一节那条酶的解释，说的正是外表与成分可以不一致。

这个系列的另外五篇

• 第 1 篇：中药也有风险？有记录的是哪一类，马来西亚怎么管
• 第 2 篇：有记录的那一类：资料怎么记录它，为什么注册审查能把关
• 第 3 篇：买回来的能不能吃？MAL 编号与 Meditag 怎么看，怎么查
• 第 4 篇：一张表看懂：手上的东西是哪一种，怎么把关
• 第 6 篇：这些情况要特别小心——哪些人先问医生与医师，不舒服时怎么办

👉 如果您不确定「我手上这包药材、这瓶中成药，到底能不能用」，欢迎透过汉方中医的线上问诊，由依 2016 年 T&CM 法令注册的医师为您评估。

无论身在何处，与持证中医师对坐。

汉方现代中医

资料来源

• 香港卫生署中医药规管办公室，专题文章〈中药服药常识、服药忌口和中药的储存方法〉— https://www.cmro.gov.hk/files/gb/useful_information/public_health/feature_articles/Knowledge_of_Taking_Chinese_Medicines_Precautions_and_Storage_Method.pdf