Androgenetic alopecia (AGA) is the most common cause of hair loss. Several FDA approved medications are available
but offer limited results. Studies have shown that the endocannabinoid system (ECS) is a key player in hair follicle
cell growth. The ECS can
nabinoid type one (CB1) receptors are well expressed in the hair follicle cells. Cannabidiol
CBD is a negative allosteric modulator of the CB1 receptor and has been shown to result in hair shaft elongation. In
addition, the hair follicle cycle phases are c
ontrolled by the ECS vanilloid receptor
–
1 (TRPV1). CBD has also been
shown to increase Wnt signaling pathways that are involved in the differentiation of dermal progenitor cells into new
hair follicles and maintaining the anagen phase of the hair cycle. Th
e effects of CBD on hair growth are dose
dependent and higher doses may result in premature entry into the catagen phase via a receptor known as vanilloid
receptor
–
4 (TRPV4). Topical application of CBD reaches hair follicles where it is a CB1 negative modu
lator, and
TRPV1, and TRPV4 agonist. A study was done of 35 subjects with AGA using a once daily topical hemp oil
formulation, averaging about 3
–
4 mg per day of CBD and minimal amounts of other cannabinoids for six months. A
hair count of the greatest area
of alopecia was carried out before treatment and again after six months. The results
revealed that men did slightly better than women, and the vertex area did better than the temporal areas. On
average there was statistically significant 93.5% increase in
hair after 6 months. All subjects had some regrowth.
There were no reported adverse effects. Since the CBD works through novel mechanisms different from finasteride
and minoxidil it can be used in conjunction with these current drugs and would be expected
to have synergistic
effects.

https://publications.sciences.ucf.edu/cannabis/index.php/Cannabis/article/view/78/47