Allantoin, an anti-inflammatory compound in the comfrey plant, increased the lifespan in worms by more than 20%.

Allantoin is pretty interesting… in other studies, for example, it has been shown to significantly speed up skin wound healing. It’s a common ingredient in some skin creams. While allantoin is commonly associated with comfrey, which contains it, comfrey also contains pyrrolizidine alkaloids that damage the liver and can lead to liver toxicity.