The AR gene is associated with androgenetic alopecia.Several genes play a role in androgenetic alopecia, variations in only one gene, AR, have been identified in people with this condition. The AR gene provides instructions for making a protein called an androgen receptor. Androgen receptors allow the body to respond appropriately to dihydrotestosterone and other androgens. Studies suggest that variations in the AR gene lead to increased activity of androgen receptors in hair follicles. It remains unclear, however, how these genetic changes increase the risk of patterned hair loss in men and women with androgenetic alopecia.

Stress can also trigger the onset of hereditary hair loss and accelerate its progression.

Physical or emotional stress may cause one-half to three-quarters of scalp hair to shed. This kind of hair loss is called Telogen effluvium. Often noticed weeks to months after the episode of stress. Hair shedding decreases over 6 to 8 months. Telogen effluvium is usually temporary. But it can become long-term (chronic).

Causes of this type of hair loss are:

• High fever or severe infection
• Childbirth
• Major surgery, major illness, sudden blood loss
• Severe emotional stress
• Crash diets, especially those that do not contain enough protein
• Medications, including retinoids, birth control pills, beta-blockers, calcium channel blockers, certain antidepressants, NSAIDs (including ibuprofen).

Sleep plays an important role in allowing the body to repair and regenerate and hair growth can be influenced by a number of factors.

Alterations in sleeping patterns have been shown to affect the body's immune function, hormone secretion, and physical and mental stamina. The hair is very sensitive to changes within the body, and hair loss is nearly always the consequence of an internal disturbance.

Sleep deprivation is a form of stress so also is hair loss resulting in a vicious cycle with one contributing to the other.

Smoke-induced premature skin ageing has study has indicated a significant relationship between smoking and baldness. The mechanisms by which smoking causes hair loss are multifactorial and are probably related to effects of cigarette smoke on the microvasculature of the dermal hair papilla, smoke genotoxicants causing damage to DNA of the hair follicle, smoke-induced imbalance in the follicular protease/antiprotease systems controlling tissue remodeling during the hair growth cycle, pro-oxidant effects of smoking leading to the release of pro-inflammatory cytokines resulting in follicular micro-inflammation and fibrosis and finally increased hydroxylation of oestradiol as well as inhibition of the enzyme aromatase creating a relative hypo-oestrogenic state.

It may also have some minor clogging effect on the scalps pores when combined with sebum.