Holly

Holly leaves contain saponins, alkaloids, caffeoyl derivatives, and small amounts of theobromine. Historically the plant was used as a diuretic, for fever, and for joint complaints, but modern controlled human data are sparse. Mechanistic information mostly comes from related Ilex species and in vitro work. Most dietary supplements use very dilute Ilex aquifolium preparations or homeopathic mother tinctures, which limits any pharmacological effect at typical label doses.

There is no established dose. The DSLD shows no standardized median dosage across products, and no RDA or upper limit has been defined. Traditional and homeopathic preparations are used in drop or milligram amounts. Avoid berries entirely as they are toxic.

No specific timing has been established. Traditional preparations were typically taken with water, away from meals if used as a diuretic.

Holly berries are toxic and can cause vomiting, diarrhea, drowsiness, and in larger amounts more serious effects, particularly in children and pets. Leaf preparations at low doses are generally considered tolerable for short-term use, but quality human safety data are limited. Standardized extracts and long-term use are not well characterized.

No well-documented drug interactions have been reported, but data are limited. Theoretical caution with diuretics is reasonable given traditional diuretic use.