PropeciaJunkie said:
It also makes sense the scalp can only take in so much so maybe it might be overkill going 15% twice a day, instead mabe only once a day would be sufficient or looking at it a different was maybe even 5% three times oer day at closer intervals.
What makes you assume that going 15% twice a day would be "overkill"? For all we know, it might actually be UNDERkill, considering that you haven't bothered to say anything about what specific vehicle you're using with the 15% minoxidil product. You absolutely CANNOT assume that all minoxidil vehicles are absorbed to exactly the same extent!! :freaked2: For your information, ordinary Rogaine types of topical vehicles (like various combinations of water, ethanol, and propylene glycol) cannot dissolve minoxidil beyond a theoretical limit that's somewhere in the vicinity of about 7.5% or so (
pure propylene glycol dissolves it to about that much). Therefore, any topical minoxidil product that claims to have a minoxidil concentration of 15% must of necessity be using some DIFFERENT vehicle than the typical hydroalcoholic ones. For example, Dr. Lee uses glycerin and azelaic acid in his 15% Xandrox.
But here's the kicker: whether or not a product that uses glycerin (or any other vehicle that's different from the typical ones) is really effective at getting that extra minoxidil into you and utilized properly is an open question that hasn't really been investigated, as far as I know. The Merck Index states in plain English that glycerin doesn't permeate the skin as well as propylene glycol. Are you going to simply ASSUME that any 15% topical minoxidil product is always going to be better than (say) an ordinary 5% product, based just on the difference in numbers?
To use an obvious but extreme example: if you dusted your head with PURE powdered minoxidil, you would be applying 100% minoxidil! But do you really think very much (if any) of that would be absorbed, or would it just sit there on top of your scalp until the next time you showered or shampooed?
The devil is in the details, as they say: it's not just what percentage of minoxidil is in your hairgrowth product, it's also what kind of a vehicle it uses and how effective that vehicle is at penetrating into the scalp and delivering its payload, not to mention how much your scalp can hold before it just can't hold any more.
