Bug2 is right about Indomethacin in his comment below. There is at least one good study that indicates that indomethacin is an AGONIST of the CRTH42 receptor…
I don’t think we can just assume that because some company out there is selling “PGD2 blockers”, that these compounds have been somehow cleared in any way, even theoretically by some scientist somewhere, to work according to the findings of Drs. Cotsarelis and Garza.
I think what some of these companies are doing is quickly latching on to this publicity and then finding ANY compound which they can claim is a “PGD2 blocker” or “PGD2 inhibitor”… even if such a compound may actually hurt your hair rather than help it.
In effect, what they are doing is making a claim which is technically true (indo is a PGD2 blocker) and selling you on something by taking advantage of your ignorance of the fact that something can actually be BOTH a PGD2 blocker AND also a PGD2 substitute which will have the exact same effect as more PGD2 on your head.
bug2 is exactly right… in the case of Indomethacin, it is both a PGD2 blocker, and also a PGD2 competitor meaning that it does the same thing as PGD2… it activates the CRTH42 receptor.
Please, people… I may not have a Ph.D but how many people on this site do? Some of us actually have formal training in biochemistry and know what we’re talking about.