Goat’s rue (Galega officinalis) is a perennial herb in the pea family (Fabaceae). While traditionally used in European medicine, its primary modern use is as a galactagogue—a substance taken to promote and increase breast milk supply in nursing mothers. It is valued for supporting the development of mammary tissue, especially for those with insufficient glandular tissue.
The Specific Link Between Goat’s Rue and Gastrointestinal Discomfort
Goat’s Rue can occasionally cause gastrointestinal discomfort, including gas and bloating, though these effects are generally mild and temporary. This reaction is related to the plant’s composition and its classification within the legume family. Like many legumes, the herb contains complex carbohydrates and fiber-like substances that the small intestine cannot fully digest.
These undigested components travel to the large intestine, where gut bacteria begin fermentation. This process releases gases like methane and hydrogen, which accumulate and lead to flatulence and bloating. The herb also contains saponins and the alkaloid galegine. While beneficial for milk supply and blood sugar, these compounds can sometimes irritate the digestive lining of sensitive individuals, contributing to an upset stomach.
Practical Adjustments for Minimizing Digestive Side Effects
Users can mitigate digestive upset by making simple adjustments to their routine. A highly effective strategy is to start with a small dose (perhaps half the recommended amount) and slowly increase intake over several days or a week. This process, known as titration, allows the digestive system time to adjust to the compounds, minimizing the sudden onset of gas and bloating.
Taking the supplement with a meal, rather than on an empty stomach, can help buffer the digestive system. Goat’s Rue is available in capsules, liquid extracts (tinctures), and teas. Some individuals find that a liquid extract, which is absorbed more quickly, is less likely to cause intestinal irritation than a capsule form. Because the herb contains fiber-like components, maintaining adequate hydration by drinking plenty of water can help the digestive tract process the material more smoothly, reducing discomfort.
Addressing Other Potential Side Effects and Safety Concerns
Beyond temporary digestive issues, Goat’s Rue is generally well-tolerated, but users should be aware of its potential to influence blood sugar levels. The active compound galegine lowers blood glucose, an effect that led to the development of the diabetes medication metformin. Individuals with diabetes or those taking blood sugar-lowering medications should consult a healthcare provider before use, as Goat’s Rue could cause an excessive drop in blood sugar, resulting in hypoglycemia.
The herb may also slow blood clotting. Therefore, it should be avoided by anyone taking anticoagulant or antiplatelet medications, or by those scheduled for surgery within two weeks. Since Goat’s Rue is a member of the legume family, people with known allergies to peanuts or other legumes should exercise caution. Although widely used during lactation, there is limited reliable information on its safety during pregnancy, so pregnant individuals should typically avoid its use.