Nettle: What Do We Really Know?

Nettle is a good example of why saying simply that “a herb has been scientifically proven” can be misleading.

The clearest clinical evidence concerns nettle root extracts and urinary symptoms associated with benign prostate enlargement. This does not mean that nettle leaves, nettle tea or every product containing nettle will have the same effect.

There are controlled human studies in other areas, including allergic rhinitis and type 2 diabetes, but the evidence is less established. Many other interesting findings – particularly those concerning antioxidant, anti-inflammatory, skin-protective or antimicrobial effects – still come largely from laboratory or experimental research.

Modern nettle research is increasingly interested in standardized extracts, where researchers know which compounds and how much of them are present. Scientists are also exploring new ways of delivering nettle extracts, including hydrogels and other carrier systems.

So with nettle, one question is especially important when reading a health claim: Which part of the plant was actually studied – the leaf or the root?