Botanical atlas

Alder Buckthorn

Rhamnus frangula

For centuries, European herbalists reached for alder buckthorn bark the way many households today reach for cascara, as a bark-derived remedy for stubborn, occasional constipation. The fresh bark was known to be far too harsh and even dangerous to take internally, so tradition insisted the bark be dried and stored away for a full year, or gently aged by heat, before it was ever brewed. Beyond the medicine chest, the wood had a quiet second life as one of the finest charcoals for gunpowder making, valued by powder mills for its clean, even burn, while the berries and bark supplied dyers and manuscript painters with soft greens and yellows.

Safety.

Fresh bark and the berries of alder buckthorn are toxic and act as violent purgatives and emetics, causing severe vomiting, cramping, and diarrhea; the berries in particular are dangerous to children and pets, who may be drawn to their dark, glossy appearance. Only bark that has been dried and aged for at least one year (or deliberately heat-aged) was ever considered for traditional use, and even then it was used briefly and in modest amounts. It should not be used during pregnancy or breastfeeding, by children, or by anyone with inflammatory bowel disease, intestinal blockage, appendicitis, or abdominal pain of unknown origin. Overuse of anthraquinone-type bark laxatives like this one can lead to dangerous electrolyte and fluid loss and may interact with heart medications such as digoxin and with diuretics. The plant is also classified as invasive in parts of North America, with sale or planting restricted in several states. Given its narrow margin of safety, please talk with a qualified herbalist or healthcare provider before ever considering internal use.