"The pathogenesis of male-pattern-baldness (male pattern baldness) is the same as acne. The first step in acne is a condition called follicular-hyperkeratinization or hyperkeratosis. Simply put, this means excess skin production inside and around the hair-follicle. The next step is caused by excess sebum production, followed by P.Acnes infestation of the pilosebaceous-follicle, with subsequent inflammation. So to summarize, male pattern baldness, just like acne, is caused by four main factors: (1) follicular-hyperkeratinization, (2) excess sebum production, (3) P.Acnes, and (4) inflammation [1].
Free-IGF-1 (insulin-like-growth-factor-1) stimulates the proliferation of keratinocytes (skin cells below the scalp). As the keratinocytes mature, they migrate to the top of the scalp and become what is known as corneocytes. If all goes well, the corneocytes are supposed to be shed off the scalp in a process called apoptosis. The shedding of corneocytes or the apoptosis of corneocytes, is under the influence of IGFBP-3 (insulin-like-growth-factor-binding-protein-3) and endogenous retinoids. In men with male-pattern-baldness, they have excess free-IGF-1 and not enough IGFBP-3 [2]. The result of this is hyperkeratinization; too much skin production, and not enough skin exfoliation. This causes the hair-follicle to be blocked by excess skin. Free-IGF-1 is required for keratinocyte proliferation in humans [3] and too much IGF-1 results in hyperkeratosis [4].
So, in order to reverse hyperkeratosis, exfoliating the scalp is needed. Using glycolic-acid topically is suggested. Glycolic-acid is what's called an alpha-hydroxy-acid. Alpha-hydroxy-acids are shown to diminish corneocyte cohesion, induce exfoliation and reverse hyperkeratosis. This should promote regrowth.