Goat’s rue: Galega officinalis
The traditional use of Goat's rue to treat diabetes has been a staple since the middle ages. Goats rue contains an alkaloid, galegine, that was found in clinical trials to decrease blood sugar and insulin resistance. This lead to the development of metformin, which is currently used in the treatment of diabetes.40
Goat’s rue is a widespread herb used by many traditions worldwide. The common name goat's rue stems from the unpleasant smell of the bruised leaves. It was one of the herbs used in Medieval Europe to treat plague victims, and as a vermifuge to treat parasitic worms. Here in North America, native healers considered goat's rue to be an aphrodisiac, a cure for impotence for men, and a healthy tonic.
The active ingredient is known to be guanidine and initially marketed under the trade name Synthalin. It was guanidine from which the most widely used and cost-effective prescription medication for the treatment of type 2 diabetes mellitus, metformin (Glucophage), was derived
Unfortunately, guanidine compounds have been associated with significant toxicities limiting their further use in clinical practice. The reported toxicities include kidney and liver damage, hypotension, ataxia, and seizures.