Pine (specifically pine tar or pine oil) has a long history of traditional use in the treatment of dandruff and various scalp conditions. Pine tar has been included in soaps, shampoos, and ointments for centuries, particularly in folk and herbal medicine traditions in Europe and North America. Its use is believed to help reduce itching, flaking, and inflammation associated with dandruff and seborrheic dermatitis. The rationale behind its use is its purported antiseptic and anti-inflammatory properties.

However, scientific validation for the effectiveness of pine tar or pine oil for dandruff is limited. There are few modern clinical trials or rigorous studies directly evaluating its efficacy for dandruff. Most available evidence is anecdotal or based on historical usage rather than robust, peer-reviewed research. The U.S. Food and Drug Administration (FDA) has recognized pine tar as an over-the-counter ingredient for certain skin conditions, but it has also been the subject of regulatory scrutiny regarding safety and efficacy.

In summary, while pine has a strong tradition of use for treating dandruff, especially in the form of pine tar shampoos, modern scientific evidence supporting its effectiveness is sparse. As such, it is primarily justified by traditional rather than scientific evidence.