Selfheal (Prunella vulgaris): Benefits, Uses, Edible Preparations, Who Should Avoid It, and Does It Treat Thyroid Nodules?

The herbal cooling teas we normally drink contain selfheal (Prunella vulgaris) as an ingredient, making it an excellent choice for cooling and relieving summer heat. Selfheal is a fairly common Chinese herbal medicine on the Taiwan, China market and has certain medicinal value. So what are the benefits, effects and edible preparations of selfheal? Who should not drink it? Does it treat thyroid nodules?

I. Selfheal

1. Introduction

Selfheal, also known as wheat-ear selfheal, iron-thread selfheal (Yunnan), iron-colour grass (Compendium of Materia Medica), Naidong (Compendium of Materia Medica), Yanmian (Compendium of Materia Medica), white flower grass, June dry, big-head flower, club grass, selfheal spike, selfheal flower, and withered-grass ear, is a perennial herbaceous plant of the Lamiaceae family. Generally, semi-dried fruit spikes are collected in summer for medicinal use, but on the Taiwan, China market the whole plant is often used. Selfheal drinks are sold in ordinary herbal tea shops. It mainly grows in sparse forests, barren hills, field ridges and roadsides, with a flowering period from April to June and a fruiting period from July to October. Because this plant withers after the summer solstice, it got this name.

2. Distribution

In China it is mainly distributed in Sichuan, Yunnan, Guizhou, Guangxi, Guangdong, Fujian, Zhejiang, Jiangxi, Hunan, Hubei, Shaanxi, Gansu, Xinjiang and Henan, among other places.

3. Morphology

The stems and leaves are ovate-oblong or ovate, with inconspicuous wavy teeth or nearly entire margins; the upper leaf surface is dark green and the underside is light green. The flowers are verticillasters densely arranged into terminal false spikes; the calyx is bell-shaped, and the corolla is purple, blue or reddish-purple.

II. Benefits and Effects of Selfheal

Benefit 1: Clearing heat and reducing internal heat, clearing the liver and improving eyesight

In traditional Chinese materia medica, selfheal is considered pungent and bitter in flavour, cold in nature, entering the liver and gallbladder meridians, and non-toxic. The whole plant is used as medicine, and the fruit spike has the effect of clearing fire and improving eyesight. Combined with mulberry leaf, chrysanthemum and cassia seed, it has a certain effect on up-flaring liver fire; combined with angelica and goji berry, it has a certain effect on clearing the liver, improving eyesight and nourishing the liver.

Benefit 2: Sterilising and lowering blood pressure

The flower spikes of selfheal can activate the liver and gallbladder to treat nervous tension and conjunctivitis caused by liver dysfunction, and have an astringent effect. They can treat bleeding gums, sore throat, haemorrhoids and excessive menstruation, and have the effects of sterilising, astringing, promoting wound healing and lowering blood pressure.

Benefit 3: Dispersing nodules and reducing swelling

Selfheal is pungent and bitter in flavour and cold in nature, and its fruit spike has the effect of dispersing nodules and reducing swelling. It can generally be used for scrofula, goitre, breast hyperplasia, acute mastitis with swelling and pain, enlarged thyroid, and lymph node tuberculosis. It is often combined with fritillary and cyperus rotundus to treat scrofula caused by stagnated liver qi transforming into fire and phlegm-fire congealing; combined with kelp and scrophularia to treat goitre; combined with dandelion to treat acute mastitis with swelling and pain; and combined with honeysuckle to treat heat-toxin sores and ulcers.

Note: (Remember that using selfheal to treat illness must follow a doctor's advice; this article is only for sharing and reference.)

III. Edible Preparations of Selfheal

1. Usage and dosage

(1) Oral: decocted in water, 6-15 g; made into pills, powders or decocted into a paste;

(2) External use: an appropriate amount decocted in water for washing or pounded and applied.

2. Edible preparations

(1) Selfheal tea: take an appropriate amount of selfheal and brew it in boiling water for 15 minutes, then drink it as tea; it has the effect of clearing the liver and dispersing nodules.

(2) Selfheal and chrysanthemum tea: put selfheal and chrysanthemum into a cup and brew in boiling water for 15 minutes; it has the effects of clearing the liver and calming the liver, and has a certain effect on red, swollen and painful eyes caused by up-flaring liver fire and on headache and dizziness caused by liver-yang rising.

(3) Selfheal and soybean soup: wash the selfheal clean and wrap it in gauze, then put it with mung beans into a pot and stew; an appropriate amount of rock sugar may be added. It has the effects of clearing heat, relieving dryness, improving eyesight and nourishing the liver.

3. Precautions

(1) Selfheal should not be taken over the long term, otherwise it may irritate the stomach and possibly cause side effects; when taking it, an appropriate amount of codonopsis and atractylodes may be added.

(2) People with weak spleen and stomach should avoid taking selfheal.

IV. Who Should Not Drink Selfheal?

1. Selfheal is cold in nature, so people with weak spleen and stomach, pregnant women, and women during menstruation are advised not to take selfheal;

2. People with an allergic constitution are not suited to drinking it. Some people will have allergic reactions to the body after taking selfheal, such as papules or erythema on the body, or generalised itching, palpitations and shortness of breath, and dizziness, and some patients may even experience gastrointestinal discomfort.

V. Can Selfheal Treat Thyroid Nodules?

Selfheal has the effect of reducing swelling and dispersing nodules, and has a certain auxiliary effect on benign thyroid nodules, but it may not cure them at the root. It is recommended to go to a hospital for examination and then receive scientific treatment.

Conclusion: As a common Chinese medicinal material, selfheal has good medicinal value, but it should not be consumed too much in daily life, so as to avoid side effects. It should also not be regarded as a medicine that can completely cure certain diseases; scientific treatment is still necessary.