Bryan said:All 2% and 5% solutions of topical minoxidil turn into saturated solutions of about 7.5%, as soon as the volatile components (alcohol and water) evaporate. If your 5% solution is too "strong" and you want to weaken it, just use a lower quantity of it (like maybe half a millilter, instead of a full milliliter).
blaze said:Bryan how does what you said above work? Does that mean that 5% minoxidil solutions really are 7.5%? Im a little confused.
knowingyou said:Bryan, I am confused as well, do you mean do you mean 7,5% from 5%?? It sounds very little. Can you post the study from Upjohn please.
Does this mean the saturated minoxidil solution in ethanol, water and propylene glycol has 10% minoxidil, instead of 7.5%?Bryan said:"The topical solution used in this study consists of a mixture of ethanol:waterropylene glycol in relative proportion (v/v) of 60:20:20. Ethanol and water are extremely volatile relative to propylene glycol and application of this vehicle to the scalp likely results quickly in a solution of minoxidil in propylene glycol approximately equivalent to the solubility maximum of 100 mg/mL. "
longhair1983 said:Does this mean the saturated minoxidil solution in ethanol, water and propylene glycol has 10% minoxidil, instead of 7.5%?
Bryan said:longhair1983 said:Does this mean the saturated minoxidil solution in ethanol, water and propylene glycol has 10% minoxidil, instead of 7.5%?
I'm assuming you meant to say "Does the mean saturated minoxidil solution in propylene glycol have 10%, instead of 7.5%?" I don't know for sure, but I suspect that the 10% figure they mentioned is more of an error than anything else. I've never seen anywhere else (including chemical reference books) that that's the absolute maximum that will dissolve in propylene glycol. In fact, a few years ago, Dr. Proctor was experimenting to see how much would dissolve in it, and was even giving out small plastic bottles of the stuff to his patients who wanted them. I used to have one of those small minoxidil bottles, clearly labeled "7.5% minoxidil". I think 7.5% is probably the more accurate figure, not 10%.
knowingyou said:So do you think 7.5% or 10% of minoxidil is more effective than 2 % or 5% minoxidil?
Bryan said:Both 2% Rogaine and 5% Rogaine are turned into 7.5% minoxidil solutions when they are applied to your scalp, but 1 mL of 5% Rogaine produces a larger final QUANTITY of it than 1 mL of 2% Rogaine. About 2 1/2 times as much. That's why 5% Rogaine works a little better than 2% Rogaine, at the same application volume. Understand?![]()
longhair1983 said:Bryan, do you think using 2 ml 5% will have the same effectiveness as 1 ml 10% minoxidil?