What REALLY is the difference between 2% and 5% Rogaine?

[Bryan]

For many years now, I've been telling people that there's no real difference between the 2% and 5% versions of topical Rogaine, and that all you have to do is simply use a larger quantity of the 2% version to get the same results as what you get with the 5% version. Now I'm going to explain to you why that is! I present to you the following study: "Relationship between Contact Time of Applied Dose and Percutaneous Absorption of Minoxidil from a Topical Solution", James J. Ferry, Judy H. Shepard, and Gregory J. Szpunar. Journal of Pharmaceutical Sciences, Vol. 79, No. 6, June 1990. This study was done under the auspices of The Upjohn Company.

This is a highly detailed and complex study examining the rate at which minoxidil is absorbed systemically after being applied topically, but that's not really what I'm talking about here. In the first paragraph of the Discussion section near the end, the authors made a very important and insightful statement. Here it is in full (added emphasis in bold is my own), and keep in mind that they are referring to the old 2% version of Rogaine, which was all they had at the time this was written:

The topical solution used in this study consists of a mixture of ethanol : water : propylene 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. Percutaneous absorption of minoxidil after topical administration presumably occurs by diffusion out of this saturated propylene glycol solution.

AHA!! See what I'm getting at? So what happens when you apply a 2% minoxidil solution to your scalp? Answer: the alcohol and water rapidly evaporate, leaving behind A SATURATED SOLUTION OF MINOXIDIL IN PROYLENE GLYCOL. And that's the same thing that happens when you apply 5% solution of topical minoxidil! The only difference between the two is that the 5% version leaves behind a larger quantity of that saturated propylene glycol solution. You could make up the difference simply by using MORE of the 2% solution (about 2 1/2 times as much). But the point here is that there's nothing magical about a 5% solution, because it turns into the same thing that a 2% solution turns into. There's just a little more of it, assuming you apply the same physical quantity (1 milliliter). But adjusting the amount you physically apply makes them exactly the same. Capiche?

 

[Petchsky]

Cool, makes sense just to buy the 5% though, no? rather than apply more 2%.

 

[Bryan]

I think it makes sense just to buy whichever version is cheaper per gram of minoxidil. Normally, that would be the 5% version. However, there's another issue here which I didn't mention before: the greater alcohol content that you get when using 2 1/2 mL of 2% Rogaine may actually make it somewhat more effective than using 1 mL of 5% Rogaine. That complicates things a bit.

 

[gjp2222]

the greater alcohol content that you get when using 2 1/2 mL of 2% Rogaine may actually make it somewhat more effective than using 1 mL of 5% Rogaine. That complicates things a bit.

Interesting statement, though is seems to contradict your previous assumption, care to provide data to support this?

 

[JWM]

And would that mean Dr. Lee's minoxidil is more effective because of its higher alcohol content?

 

[stampede]

You're going to end up putting more of the carrier on your head with the 2%, to make it up to the 5% strength.

And, as we know, the carrier can be quite irritating.

 

[Cassin]

And would that mean Dr. Lee's minoxidil is more effective because of its higher alcohol content?

Yes...or the foam version. "versa foam."

I rotate between foam and Dr Lees and I use a lot of 5% once a day to cover my entire scalp. Probably about 2ml a day.

 

[JWM]

You mean 2 ml in one application?

 

[Cassin]

You mean 2 ml in one application?

Pretty much...when I use Dr Lees a little more than 1.25 yes but the foam 2ml for sure.

 

[Bryan]

the greater alcohol content that you get when using 2 1/2 mL of 2% Rogaine may actually make it somewhat more effective than using 1 mL of 5% Rogaine. That complicates things a bit.

Interesting statement, though is seems to contradict your previous assumption, care to provide data to support this?

That idea comes from yet another study which has been discussed a few times on the hairloss sites. It was an in vitro study in which minoxidil was applied to mouse skin, and the penetration using various vehicles with different relative quantities of alcohol and propylene glycol was tested. They found that the most effective vehicle (the one that provided the most penetration into the mouse skin) was the one that had 90% alcohol and 10% propylene glycol. Any vehicle that had less alcohol than that, or more alcohol than that (like 100% alcohol) was less effective.

So it's not entirely out of the question that using 2 1/2 mL of the old Rogaine (which contains 60% alcohol) could conceivably be a bit more effective than using 1 mL of the new Rogaine, which contains only 30% alcohol, if I remember correctly. It would be fascinating if they'd test that hypothesis with an actual study.

 

[Bryan]

And would that mean Dr. Lee's minoxidil is more effective because of its higher alcohol content?

Could be.

 

[Joey Ramone]

Since when was throwing junkloads of ethanol on your scalp a good idea?

 

[neis]

Hi
Bryan,

I wanted your thoughts on my hair problem


I am John and I am 20 years old now

In the age of 18 I had lost a lot of hair, so I started using rogaine 5% extra strength for 3 months and I regrew all my hair back, and all my relatives that had seen me after so much time they thought it was a miracle. Unfortunately because of itching I made the wrong to stop it and I lost all the hair that I regrew with rogaine. Before 1 year I started again the treatment of rogaine for 4 months but no regrowth was seen,so I stopped it. Now I started again rogaine 5% extra strength(3 months on treatm), propecia(6 months on treatm) and proxiphen(1,5 months on treatm).
I wanted to ask you if my hair follicles got used to regaine 5% and they don't react , or they have died ? or rogaine 5% extra strength will need more time to regrow my hair?(I mean more than 3 months that I am using it now, because the first time I used it ,in 2,5 months it had regrew all my hair)

Thanks
Chris

 

[hair_tomorrow]

> What REALLY is the difference between 2% and 5% Rogaine?
It's like ... 3%.

Right?

:innocent:

(sorry)

 

[gjp2222]

the greater alcohol content that you get when using 2 1/2 mL of 2% Rogaine may actually make it somewhat more effective than using 1 mL of 5% Rogaine. That complicates things a bit.

Interesting statement, though is seems to contradict your previous assumption, care to provide data to support this?

That idea comes from yet another study which has been discussed a few times on the hairloss sites. It was an in vitro study in which minoxidil was applied to mouse skin, and the penetration using various vehicles with different relative quantities of alcohol and propylene glycol was tested. They found that the most effective vehicle (the one that provided the most penetration into the mouse skin) was the one that had 90% alcohol and 10% propylene glycol. Any vehicle that had less alcohol than that, or more alcohol than that (like 100% alcohol) was less effective.

So it's not entirely out of the question that using 2 1/2 mL of the old Rogaine (which contains 60% alcohol) could conceivably be a bit more effective than using 1 mL of the new Rogaine, which contains only 30% alcohol, if I remember correctly. It would be fascinating if they'd test that hypothesis with an actual study.

This does not translate to a human equivalent, human skin does not absorb in the same manner, therfore it would be erroneous to make such an assumption.

Do you have any data on actual in vivo human skin, the "gold standard"?

 

[gjp2222]

And would that mean Dr. Lee's minoxidil is more effective because of its higher alcohol content?

That would be doubtful, PPG's purpose extends farther than as a penetration enhancer.

 

[gjp2222]

And would that mean Dr. Lee's minoxidil is more effective because of its higher alcohol content?

Yes...or the foam version. "versa foam."

I rotate between foam and Dr Lees and I use a lot of 5% once a day to cover my entire scalp. Probably about 2ml a day.

I hope you don't mean that! Have you not read the hair count studies posted on this forum? Bottom line, liquid is superior in hair counts over foam, and that's really all that matters.

I don't understand why it so hard for some people to grasp this, they keep asking the same question so as to justify their use of the foam.

 

[Cassin]

And would that mean Dr. Lee's minoxidil is more effective because of its higher alcohol content?

Yes...or the foam version. "versa foam."

I rotate between foam and Dr Lees and I use a lot of 5% once a day to cover my entire scalp. Probably about 2ml a day.

I hope you don't mean that! Have you not read the hair count studies posted on this forum? Bottom line, liquid is superior in hair counts over foam, and that's really all that matters.

I don't understand why it so hard for some people to grasp this, they keep asking the same question so as to justify their use of the foam.

Relax. I also use the foam because its so easy on the skin. I'm pretty sensitive to treatments and the high alcohol is a bit rough if I use it too long. The foam is very gentle and relieves the itching I build up from Dr Lees.

 

[Bryan]

This does not translate to a human equivalent, human skin does not absorb in the same manner, therfore it would be erroneous to make such an assumption.

I indicated myself that the greater alcohol content _may_ be more effective, that it could conceivably be more effective, that it's not entirely out of the question that it could work that way, that the idea is just a hypothesis that needs to be tested, etc. But thanks for being skeptical about mouse skin versus human skin, and pointing out what I had already said in plain English!

 

[Bryan]

In the age of 18 I had lost a lot of hair, so I started using rogaine 5% extra strength for 3 months and I regrew all my hair back, and all my relatives that had seen me after so much time they thought it was a miracle. Unfortunately because of itching I made the wrong to stop it and I lost all the hair that I regrew with rogaine. Before 1 year I started again the treatment of rogaine for 4 months but no regrowth was seen,so I stopped it. Now I started again rogaine 5% extra strength(3 months on treatm), propecia(6 months on treatm) and proxiphen(1,5 months on treatm).

I wanted to ask you if my hair follicles got used to regaine 5% and they don't react , or they have died ? or rogaine 5% extra strength will need more time to regrow my hair?(I mean more than 3 months that I am using it now, because the first time I used it ,in 2,5 months it had regrew all my hair)

I wish I knew what was going on with you, Chris (or John). Are you sure your balding is due to male pattern baldness? Have you seen a doctor about all this?