Geographical Origin & Distribution
From its Mediterranean origin, Agnus Castus spread to various parts of Europe, Asia, and the Middle East. Today, it is naturalised in many regions around the world, including North america and Australia.
Historical Use
The name “Agnus Castus” comes from two Latin words: “agnus” (meaning “lamb”) and “castus” (meaning “chaste” or “pure”). This reflects the plant’s ancient association with chastity and the belief that it helped reduce sexual desire. It’s use has been mentioned in the ancient Greece and Rome, often being associated with chastity and purity. During the Middle Ages, Agnus Castus continued to be used in monastic settings to maintain chastity, as it was believed to have an anaphrodisiac effect (reducing libido). This is where the name “Monk’s Pepper” comes from, as it was commonly used by monks for this purpose.
Medical Use
The fruits are harvested in autumn and used dry in whole, crushed, or milled before feeding. Alternatively, the fruits are prepared as a liquid extract.
Leaves
The leaves are palmate (resembling the shape of a hand) with 5 to 7 lance-shaped leaflets. The leaflets are long and narrow, tapering to a point. Interestingly, the upper side is dark green, while the underside is grayish-green.
Flowers
The flowers are usually lavender or violet, though white or pink flowers are less common. The bloom from late spring to early fall in spiked clusters at the end of branches and have a pleasant, slightly spicy fragrance that attracts pollinators such as bees and butterflies.
Size
The plant typically grows between 1-5 m tall, though it can sometimes reach up to 6 meters under ideal conditions.It spreads wide , with the canopy extending up to 4 m wide.
Fruits
The fruits are small, round, and berry-like, measuring about 3-5 mm in diameter. They turn from green to dark purple or black as they mature. They have a peppery flavor, which is why Agnus Castus is sometimes called Monk’s Pepper. Those are the part most commonly used for medicinal purposes, particularly in herbal remedies.
Growing Conditions
Agnus Castus prefers warm, Mediterranean-type climates, but it can also grow in temperate regions with adequate sunlight. It thrives in well-drained soil and tolerates poor, sandy, or even gravelly soil. Full sun is preferred for optimal flowering and fruit production, though it can tolerate partial shade.
Harvest
Agnus Castus berries are harvested in late summer or early autumn once the plant has finished flowering. By then, the berries have fully ripened and turned dark purple. Dry the seeds in a warm, dry, and ventilated area. Test the ripeness by gently squeezing a berry—if it releases its dark purple juice, the berries are ripe and ready for harvest.
Active Substances
- Iridoid Glycosides: anti-inflammatory and antioxidant properties, regulatory effect on the female reproductive system. These include eurostide, agnuside, and aucubin.
- Flavonoids: powerful antioxidants with anti-inflammatory and hormone-modulating properties. These include casticin, vitexin, kaempferol, isovitexin, and orientin.
- Diterpenes: plant compounds known for their hormone-modulating effects. These include viteagnusin, vitexilactone, rotundifuran, and 6-beta,7 beta-diacetoxy-13-hydroxy-labda-8,14-dien.
- Essential Oils: Agnus castus contains a variety of essential oils that contribute to its medicinal aroma and pharmacological properties. These include limonene, sabinene, cineol, and pinene.
- Triterpenoids: Compounds, such as 3-epi-maslinic acid, with anti-inflammatory and antioxidant effects, supporting the plant’s overall health benefits.
- Tannins: astringent compounds, such as catechin, with antioxidant and antimicrobial properties that may contribute to Agnus Castus’ ability to relieve inflammation and protect against infections.
Chemical Breakdown (per 100g of dried Agnus Castus berries)
Iridoid Glycosides: Agnuside (0.5%–0.8%), Aucubin (0.6%–1.0%)
Flavonoids: Casticin (0.01%–0.08%), Kaempferol (traces), Isovitexin (traces)
Diterpenes: Rotundifuran (0.02%–0.05%), Vitexilactone (0.01%–0.03%)
Essential Oils: 0.5%–1.0%
Triterpenoids: traces
Tannins: 3%–4%
Uses of Agnus Castus for Horses & Dogs
While Agnus Castus is generally considered safe for horses & dogs, it’s important to introduce any new plant or supplement gradually and monitor your horse’s response. Don’t feed to pregnant animals!
- Hormonal Balance in Mares:
- Agnus Castus can help manage hormonal imbalances in mares, especially those experiencing irregular heat cycles, mood swings, or discomfort during estrus (heat).
- It is thought to reduce symptoms of irritability, moodiness, and even aggressive behavior related to hormone fluctuations.
- The herb may also help regulate reproductive hormones like progesterone and estrogen, promoting a more regular cycle.
- Hormonal Balance in Dogs:
- Agnus Castus is often used to help regulate reproductive hormones in both male and female dogs.
- False pregnancies (pseudo-pregnancy) in unspayed female dogs, which can cause symptoms like lactation, nesting behavior, and lethargy.
- Irregular heat cycles in female dogs, helping to normalize their estrous cycle.
- Excessive mounting or other hormonal behaviors in male dogs, as it may help reduce testosterone-driven behaviors.
- Cushing’s Disease (PPID) in Horses:
- In older horses, Agnus castus is often used to support horses suffering from Pituitary Pars Intermedia Dysfunction (PPID), commonly known as Cushing’s disease. This condition causes the pituitary gland to overproduce certain hormones, leading to symptoms like excessive thirst, abnormal hair growth, lethargy, and laminitis.
- The herb is believed to help regulate the pituitary gland’s function and may help lower adrenocorticotropic hormone (ACTH) levels, reducing the severity of Cushing’s symptoms.
- Cushing’s Disease (PPID) in Dogs:
- In older dogs, Agnus Castus can be used as a natural supplement to help balance the overproduction of cortisol from the adrenal glands.
- Cushing’s disease can lead to excessive thirst, weight gain, thinning hair, and lethargy. Agnus Castus may help regulate the adrenal and pituitary function in dogs with this condition, similar to its use in horses
- Anti-Inflammatory and Antioxidant Effect:
- Agnus Castus has mild anti-inflammatory and antioxidant properties, which can be beneficial in supporting overall health, reducing inflammation, and promoting better immune function in horses and Dogs.
- Older Horses & Dogs:
- For older horses and dogs, Agnus Castus may provide general support for hormonal and metabolic health, especially in those experiencing age-related hormone issues such as Cushing’s disease or insulin resistance.
Additional sources: Journal of Applied Pharmaceutical Science Vol. 12(03), pp 034-044, March, 2022; National Center for Biotechnology Information; De Guyter – Phytochemical screening and antioxidant activity of Vitex agnus-castus L.; Researchgate – Evaluation of the phenolic compounds and the antioxidant potentials of Vitex agnus-castus L. leaves and fruits