Minoxidil is one of the most widely used, widely available treatments for hair loss, and it did not get that way by accident. It is one of three FDA approved treatments for hair loss, and is the only topical treatment for it.
Getting FDA approval is no easy task; it requires rigorous clinical testing that shows consistent, significant results and benefits. In short, minoxidil was shown in studies to be a reliable hair loss treatment that, unlike many other hair loss treatments, was able to consistently regrow hair.
The problem is that these studies were conducted a long time ago and are beginning to become somewhat outdated.
2% minoxidil was first approved in 1988 for male androgenic alopecia (pattern hair loss), and later approved for women in 1992. Then, in 1998, a 5% version was approved for men and was shown to be much more effective (more on that later). This is essentially the last time minoxidil has been tested in a clinical setting; it’s been over 20 years.
Within those last 20 years many people began speculating that, just like how 5% yielded better results than 2% minoxidil, the more you increase the percentage of minoxidil (i.e. to 10 or 15%, which are the other two available formulations), the more effective it will be.
In this article, we are going to look at what research is available to determine if the notion that “the stronger the minoxidil, the better the hair growth” is plausible or not. The aim is to help people who are not achieving the regrowth they might have envisioned on 5% to make an informed decision about whether-or-not it is worth it to seek out (and probably pay a lot more for) stronger minoxidil.
A brief overview of how minoxidil works
Minoxidil is called a vasodilator, meaning it helps open (dilate) blood vessels to promote blood flow. When it is applied to the scalp, blood flow to the hair follicles is increased.
Blood carries vital oxygen and nutrients that the hair uses to grow. Sometimes, in people with hair loss, blood flow is lower which means that their hair is not getting the proper nutrition that it needs (1). But, by increasing blood flow, minoxidil can help bring the blood flow back to healthy levels so that the hair can grow in a healthy manner.
Stronger minoxidil: what the research says
Does the claim that the stronger the minoxidil you use, the better the hair growth, have any legitimacy?
There has not been a lot of research conducted on either 10%, nor 15% minoxidil, meaning that the results we are going to talk about have yet to be confirmed by other studies. There are however, several studies that compare 2% to 5% minoxidil, which is where the bulk of the claims that stronger minoxidil is more effective come from.
One study (2) evaluated 393 men with hair loss over a period of 48 weeks. They were divided into three groups: a 5%, a 2%, and a placebo group, all of which applied minoxidil twice a day. The efficacy was measured by scalp hair counts and internal assessments.
Once the study had concluded, it was found that 5% was far superior to 2% as it showed 45% more hair growth. It was also found that men who used the 5% solution responded quicker and were in better psychological states than those who used 2%.
This studies result was not one of a kind either; several studies have had similar findings (3,4). All of these similar findings across studies is what led people to essentially assume that the higher the minoxidil, the more effective it was going to be, but let’s take a step back for a second.
Another study we need to look at compared the efficacy of 10% to 5% minoxidil (5).
This study was double-blind, plabeco-controlled, and took place over a 36-week time span. It evaluated 90 men with male pattern hair loss, with one group applying 5%, one group 10%, and one group with a placebo, and the results were very interesting.
It was found that, contrary to what the researchers believed would happen, 5% minoxidil was shown to be superior over both the 10% and the placebo in terms of total vertex and frontal hair count. Beyond that, the irritation and psychological stress (due to shedding) were markedly higher in the 10% group.
Although this is the only study of its kind, it makes a very strong argument against the higher percent = more effectiveargument.
There is only one other relevant study (6). It took a look at 15% minoxidil (and is the only study to do so; although it did not compare it to 5%). Researchers wanted to test if the 15% solution would work in females who were identified as “non-responders” to 5% minoxidil (the researchers did a study previously to determine the threshold for what delegates someone as a non-responder).
The study found that after 12 weeks, 60% of the subjects achieved a significant response during evaluation/based on photographic analysis.
In conclusion, what does all this research mean?
In short, the small amount of research, as well as the varying results across studies, makes it hard to determine whether or not the claim has any merit.
As we all know, everyone is different and will respond to treatments differently, which is why we cannot make conclusions one way or another. Based on the evidence, the only things we can say for sure are:
1. 5% minoxidil has been proven to be much more effective than 2% minoxidil, and this is where the assumptions that higher percentage minoxidil is more effective come from
2. If you are a non-responder to 5%, you may be able to increase your chances of minoxidil being effective by using a stronger alternative
What we cannot say for sure is:
1. The higher percentage the minoxidil, the better results you will get
2. 5% is more effective than 10% (or possibly higher)
So, if you have given 2% or 5% a legitimate chance (i.e. 6 months or more) it may be worth it to seek out a 10% or 15% solution and give it a whirl. But, for those of us who are responding to 5% (even those who have not achieved amazing results), there is not enough evidence to say that upping the percentage will help promote more regrowth.