Bamboo, specifically bamboo extract, is sometimes used in supplements targeting hair health due to its high silica (silicon dioxide) content. Silica is an essential trace element that plays a role in the synthesis of collagen, which is important for the structural integrity of hair, skin, and nails. Some scientific studies have suggested that silica supplementation may improve hair strength and thickness by supporting collagen production and possibly influencing hair follicle function. For example, a small study published in Archives of Dermatological Research (2007) found that silicon supplementation (using orthosilicic acid rather than bamboo specifically) improved hair tensile strength in women with fine hair.

However, direct clinical studies investigating bamboo extract itself for hair health are limited. Most of the available evidence is either extrapolated from the general effects of silica or based on in vitro or animal studies. Human trials using bamboo extract as the primary intervention are lacking. As a result, while there is a plausible scientific rationale for bamboo extract's use in supporting hair health due to its silica content, the direct evidence base is modest and not yet robust.

In summary, while the use of bamboo for hair health is grounded in scientific reasoning about silica, the specific clinical validation for bamboo extract itself is limited, resulting in a low to moderate evidence rating.