When it comes to scientific evidence in support of Ramatroban for hair growth, very little exists. While it is becoming a more popular hair growth formula, researching various scientific journals comes up with only a few finds.
Ramatroban is “an orally-active, dual Gpr44 and thromboxane A2 receptor antagonist” which was developed in Germany. It is currently only released in Japan for use as a treatment to allergic rhinitis, or hayfever.
While there is very little empirical evidence of Ramatroban helping reduce hair loss or increase hair growth, there is likely to be some benefit because of it’s role as a Gpr44 Antagonist. According to a 2012 study by the title Prostaglandin D2 inhibits wound-induced hair follicle neogenesis through the receptor, Gpr44:
In addition to previous studies suggesting that Gpr44 antagonists may be beneficial in androgenetic alopecia, our results suggest that formulations of Gpr44 antagonists may decrease scarring during wound healing. A specific example is ramatroban, an orally-active, dual Gpr44 and thromboxane A2 receptor antagonist, which is approved in Japan for the treatment of allergic rhinitis in humans Future studies could examine the effect of ramatroban in stimulating hair follicle neogenesis.
Based on what we know so far, what role does Gpr44 antagonists have when it comes to hair loss and potential hair regrowth? Well, according to the evidence, the role of Prostaglandin D2 (a lipid-like compound that has a hormone-like effect in mammals) works to inhibit hair lengthening. Gpr44 is one of the receptors of Prostaglandin D2. Researching the effects of Prostaglandin in body tissues proves difficult due to the fact that it seems to have different effects depending on the tissue that it is in.
According to a 2014 study by the name Does Prostaglandin D2 hold the cure to male pattern baldness?:
Recently, however, work from our group and others have added to the understanding of AGA and suggested novel therapies. We have demonstrated that Prostaglandin D2 is elevated in male balding scalp and that it functionally inhibits hair lengthening through its receptor GPR44, which directly suggests treatments for male pattern hair loss.
This information has been vital in research regarding what is known as androgenetic alopecia (AGA). AGA is generally thought to result from DHT as one ages. Evidence has shown, however, that prostaglandin D2 was higher in those who are bald as opposed to those who had hair. This shows that prostaglandin D2 is thought to prevent the growth of hair, thus causing baldness.
There have been studies that researched the mechanisms that prostaglandin D2 play in accordance to male pattern baldness. According to the 2012 study Prostaglandin D2 Inhibits Hair Growth and Is Elevated in Bald Scalp of Men with Androgenetic Alopecia:
The mechanisms for decreased hair growth in this disorder are unclear. We show that prostaglandin D2 synthase (PTGDS) is elevated at the mRNA and protein levels in bald scalp compared to haired scalp of men with AGA. The product of PTGDS enzyme activity, prostaglandin D2 (PGD2), is similarly elevated in bald scalp. During normal follicle cycling in mice, Ptgds and PGD2 levels increase immediately preceding the regression phase, suggesting an inhibitory effect on hair growth.
This research concludes that “PGD2-GPR44 pathway as a potential target for treatment.”, meaning that Ramatroban, which is a Gpr44 antagonist, may play a role in the potential for hair growth. However, there is very little evidence linking the two together at this time. There is, however, future studies to be placed in order to research this claim.