Clinical trial comparing 5% and 1% topical minoxidil for Androgenetic Alopecia

[bornthisway]

J Dermatol. 2009 Aug;36(8):437-46.Click here to read

Randomized clinical trial comparing 5% and 1% topical minoxidil for the treatment of androgenetic alopecia in Japanese men.

Tsuboi R, Arano O, Nishikawa T, Yamada H, Katsuoka K.
Department of Dermatology, Tokyo Medical University, Tokyo, Japan.

Minoxidil is efficacious in inducing hair growth in patients with androgenetic alopecia by inducing hair follicles to undergo transition from the early to late anagen phase. Although the efficacy of 1% topical minoxidil has been confirmed in Japan, no controlled study of 5% topical minoxidil has been conducted using male Japanese subjects. The objective of this trial was to verify the superiority in clinical efficacy of 5% topical minoxidil to 1% topical minoxidil in a double-blind controlled study with male, Japanese androgenetic alopecia patients as the subjects. The trial included 300 Japanese male patients aged 20 years or older with androgenetic alopecia who were administered either 5% topical minoxidil (n = 150) or 1% topical minoxidil (n = 150) for 24 weeks. The mean change from the baseline in non-vellus hair/cm(2), the primary efficacy variable, was 26.4 (n = 142) in the 5% topical minoxidil group and 21.2 (n = 144) in the 1% topical minoxidil group at 16 weeks, the main time point for the evaluation. The difference between the groups was significant (P = 0.020). The incidence of adverse events was 8.7% (13/150) in the 5% group and 5.3% (8/150) in the 1% group, with no significant difference between the groups (chi(2)-test: P = 0.258). Our findings confirmed the superiority of 5% topical minoxidil to 1% topical minoxidil in treating Japanese men with androgenetic alopecia.

PMID: 19691748

 

[Bryan]

I really welcome that new study, because it provides still more evidence for what I've been saying for years on hairloss forums: 2% Rogaine is nearly as effective as 5% Rogaine. You wouldn't believe the arguments I had years ago with people on alt.baldspot who absolutely INSISTED that only 5% minoxidil did any good at all, while 2% was as useless as dripping water on your head.

Now the only remaining thing to do is get the word out that when you get right down to it, it doesn't really even make any particular difference which version you use! You can use 2 1/2 mL of the 2% solution, and it will be about the same effectiveness as using 1 mL of the 5% solution, because they both apply the same amount of minoxidil in similar vehicles.

 

[wesleyBelgium]

seems to me that higer dose = more result so...

2% minoxidil -> 5% minoxidil -> 12,5% -> 15% -> minoxidil-sulfate ?

 

[guybrush]

I'd like to see a comparison between once a day and twice a day.

 

[somone uk]

i remember my tricoligist telling me there is little clinical evidence between 2% and 5% other than "5% may give faster results"
though the thing is in the uk there are really no generics sold apart from boots and the only minoxidil you can buy in bulk is...5% regaine which is cheaper than boots generics
i would be intrested to see a trial between 0.5ml vs 1ml of 5%, i know people say "it's the same as 1ml of 2.5%" but there is no trial to prove that

 

[Bryan]

i remember my tricoligist telling me there is little clinical evidence between 2% and 5% other than "5% may give faster results"

There are at least two clinical trials that made a direct comparison between 2% and 5% versions of Rogaine. I've posted the graphs from one of them (the 1999 study by Vera Price) umpteen different times on this site.

i would be intrested to see a trial between 0.5ml vs 1ml of 5%, i know people say "it's the same as 1ml of 2.5%" but there is no trial to prove that

Huh? What are the two things you want to see compared??

 

[somone uk]

i remember my tricoligist telling me there is little clinical evidence between 2% and 5% other than "5% may give faster results"

There are at least two clinical trials that made a direct comparison between 2% and 5% versions of Rogaine. I've posted the graphs from one of them (the 1999 study by Vera Price) umpteen different times on this site.

[quote="somone uk":e3992nxg]i would be intrested to see a trial between 0.5ml vs 1ml of 5%, i know people say "it's the same as 1ml of 2.5%" but there is no trial to prove that

Huh? What are the two things you want to see compared??[/quote:e3992nxg]
i meant 0.5ml 5% minoxidil vs 1ml 2.5%
i want to see if the volume that is applied on the scalp makes a differance or not, ie if distrobution makes much of a differance etc etc

i'll go check for the minoxidil comparisons

 

[Bryan]

i meant 0.5ml 5% minoxidil vs 1ml 2.5%
i want to see if the volume that is applied on the scalp makes a differance or not, ie if distrobution makes much of a differance etc etc

I don't know of any official version of Rogaine that was ever released that contained 2.5% minoxidil, but all that really matters is how much total minoxidil you apply to your scalp (at the very least, as far as 2% or 5% Rogaine is concerned). Applying 2 1/2 mL of 2% would have the same hairgrowth effect as applying 1 mL of 5%. Why? Because once you apply them to your scalp, they both turn into the same thing: a saturated solution (about ~7.5%) of minoxidil in propylene glycol.

 

[somone uk]

oh i see ,
in other words some of alcohol evaporates on your scalp?
i wondered why 2% has more alcohol than 5%
wouldn't this research also suggest that high concentrations like 10% + are not worth the money?

 

[Bryan]

oh i see ,
in other words some of alcohol evaporates on your scalp?

Sure, the great majority of it. The alcohol and water in the topical vehicle are far more volatile than the propylene glycol, so it doesn't take long for them to evaporate, leaving behind the minoxidil dissolved in the propylene glycol. The maximum solubility of minoxidil in propylene glycol is somewhere around 7.5% to 10%.

i wondered why 2% has more alcohol than 5%

More alcohol, and less propylene glycol.

wouldn't this research also suggest that high concentrations like 10% + are not worth the money?

Don't know. To get minoxidil to dissolve to that high a percentage, you either have to use a completely different type of vehicle than what's used in ordinary Rogaine, or do some serious chemical "tricks" to it, to get it to dissolve (note that what Dr. Lee does to get minoxidil to dissolve to 15% in that one product of his is a closely guarded secret). How well those ultra-high minoxidil concentrations actually work at growing hair is a matter of conjecture. Whether or not they're worth the money, I have no idea.

 

[somone uk]

hmm i have just been reading dr farjo's research on minoxidil and it refranced http://jcs.biologists.org/cgi/reprint/97/3/463?ijkey=4c1253f825d602a859b8f0a4a389b098d4af7d48

in vitro follicle growth in 72 hours

200ug/ml 0.63±0.05
10ug/ml 0.83±0.03
200ng/ml 0.91 ±0.03

kinda suggests less is more :dunno:

 

[guybrush]

I've been aplying 0.5ml/24h for 1 month and would say the shedding is nearly the same as when I used it 0.75ml/12h last year.

I started this regimen after reading several studies. I suspect results will be nearly the same, they may just take a bit more to appear, that's all.

This leaves me free of sides and free of minoxidil in my hair during the day