Dopamine is a novel, direct inducer of catagen in human scalp hair follicles in vitro.

Br J Dermatol. 2012 Nov 23. doi: 10.1111/bjd.12113. [Epub ahead of print]
Dopamine is a novel, direct inducer of catagen in human scalp hair follicles in vitro.
Langan EA, Lisztes E, Bíró T, Funk W, Kloepper JE, Griffiths CE, Paus R.

Dermatology Research Centre, The University of Manchester, Manchester Academic Health Science Centre, Manchester, U.K Experimental Dermatology, Universitätsklinikum Schleswig Holstein, Lübeck, Germany DE-MTA 'Lendulet' Cellular Physiology Research Group, Department of Physiology, University of Debrecen, H-4032 Debrecen, Hungary Clinic Dr Kozlowski, Munich, Germany.

Background:  Although there are clinical reports of hair loss associated with levodopa and dopamine agonists, it is unclear whether dopamine exerts any direct effects on the human hair follicle (HF). Objectives:  Given the widespread use of dopamine agonists and antagonists in clinical medicine, we sought to determine whether dopamine exerts direct effects on human HF growth and pigmentation in vitro, and whether human HFs express dopamine receptors (DRs). Methods:  Microdissected human scalp HFs from women were treated in serum-free organ culture for 7 days with dopamine (10-1000 nmol L(-1) ), and the effects on hair shaft production, HF cycling (i.e. anagen-catagen transition), hair matrix keratinocyte proliferation and apoptosis, and HF pigmentation were measured by quantitative (immuno)histomorphometry. Results:  Dopamine had no consistent effect on hair shaft production, but did promote HF regression (catagen). It was also associated with significantly reduced proliferation of HF matrix keratinocytes (P < 0.01) and reduced intrafollicular melanin production. Dopamine receptor transcripts were identified in HFs and skin. Conclusions:  These data provide evidence that dopamine is an inhibitor of human hair growth, via the promotion of catagen induction, at least in vitro. This may offer a rational explanation for the induction of telogen effluvium in some women treated with dopamine agonists such as bromocriptine. Moreover, dopaminergic agonists deserve further exploration as novel inhibitors of unwanted human hair growth (hirsutism, hypertrichosis).

interesting cs. this may explain why many men report hairloss due to an excessive sex drive. increased dopamine is related to increased sex drive / hypersexual behaviours.

Xenon wrote:interesting cs. this may explain why many men report hairloss due to an excessive sex drive. increased dopamine is related to increased sex drive / hypersexual behaviours.

I don't think it's the excessive sex drive that would cause the hairloss, as much as prolonged sexual exhaustion. But yeah, you have the right idea.

This has been quite a popular topic in the past. My experience in this has been interesting because during my worst bouts of inflammation and terrible hair, sex was the most impacting. However, once I got everything under control with diet, supplements, the inflammation gradually reduced to a point of nothing.

In other words, while intercourse could be an instigator, it is not really the underlying problem. If everything is in balance (everyone's needs being a little different), sex should not pose a threat anymore.

Having said that, I should mention though that there is a sub group of people and to my knowledge this has not been formerly studied, but those with a precocious sex drive or overly active with porn, etc. usually have an imbalance, within the HTPA. This would have to be corrected naturally.

If so, why taking two dopamine antagonist for 3 months didn't do anything to help my hair?