You have been using minoxidil faithfully. Twice a day, for months on end, strictly by the book. And yet, you don’t see a single difference in the mirror. No new hair, no reduced shedding, nothing. Meanwhile, your brother or your colleague already had visibly thicker hair after eight weeks.
That is frustrating, and it feels like you are doing something wrong. But in many cases, it is not your fault. It is due to an enzyme in your scalp you have never heard of, which determines whether minoxidil can work for your body at all.
Minoxidil is not a ready-made remedy
What few people know: the stuff you rub onto your scalp is not the active ingredient itself. Minoxidil is a so-called prodrug. Your body must first convert it into its active form, minoxidil sulfate, before it can do anything for your hair follicles.
That conversion happens with an enzyme called sulfotransferase, abbreviated as SULT1A1. This enzyme is present in your skin and hair follicles, and it does the real work. Without enough SULT1A1 activity, minoxidil largely remains on your scalp without doing anything, no matter how often you apply it.
Why some men do not respond
The amount of SULT1A1 activity varies from person to person. Research into this enzyme in plucked hair follicles shows a clear difference between people who do respond to minoxidil and those who do not: in non-responders, the enzyme activity is significantly lower on average.
In some studies, this difference is so consistent that researchers have turned it into a test method, the so-called minoxidil response test. In this process, a hair follicle is tested for enzyme activity to predict whether someone will benefit from minoxidil, even before they have spent months using it.
How many men actually see results?
This is where much of the marketing around minoxidil falls short: it is often presented as if it works for everyone, as long as you stick with it long enough. The figures from research tell a more nuanced story. A significant portion of users, somewhere between sixty and seventy percent according to several studies, sees little to no noticeable effect from minoxidil alone.
That does not mean minoxidil is a bad product. For the group that does respond to it, the effect is often substantial and well-supported. It primarily means that minoxidil is no guarantee, and that "it just doesn't work for me" is more often a biological fact than a lack of perseverance.
Can you have this tested beforehand?
In theory, yes. There are test kits that measure sulfotransferase activity in a hair follicle and use that to predict whether you are likely to respond to topical minoxidil or not. Some studies show that such a test can filter out non-responders with high accuracy.
In the Netherlands, this test is difficult to find in practice. It is not a standard part of a GP visit or dermatologist consultation, and most clinics still work with the old method: just start and evaluate after six months. For most men, this means you start the process without knowing in advance which group you fall into.
What if your serum really doesn't work for you
Before you conclude that minoxidil does nothing for you, it is smart to check these two things first:
- Have you used it daily and consistently for at least four to six months? Hair growth is slow, and many people stop too early, before the effect could have become visible.
- Are you using it correctly, on a dry scalp, without washing it away immediately or covering it with a cap?
If the answer to both questions is yes, and you still notice nothing after half a year, then it is not a crazy idea to assume that your scalp does not activate minoxidil well. In that case, there are a few routes you can consider.
One option is to switch to a product that works via a different route, such as finasteride or dutasteride. These target DHT, not the SULT1A1 enzyme, so a minoxidil non-response says nothing about whether those products would work for you. These are prescription medications with their own list of possible side effects, so that is a conversation worth having with a doctor, not a decision you make on the fly.
Another route is a serum that does not rely on the same enzyme. Ingredients such as those in Hairborn Growth Serum work by activating stem cells in the hair follicle and improving blood flow, rather than through the conversion process that minoxidil requires. That does not mean it necessarily works more strongly, but it does mean it acts via a different mechanism. And that is exactly relevant if your scalp happens to be deficient in that one enzyme.
Combining can also be a solution
There has also been research into combining minoxidil with a substance that gives SULT1A1 activity a boost. In a study of men who were previously considered non-responders, the response improved for a majority of the participants as soon as they used this combination instead of minoxidil alone. Non-response is therefore not necessarily permanent. The enzyme can sometimes use a helping hand.
Something similar applies to the combination of a serum with a derma roller. Microneedling increases the permeability of your scalp, allowing active ingredients to penetrate deeper. That does not solve the enzyme problem of minoxidil itself, but it can help with other products you use.
What this means for you
If minoxidil does not work for you, that does not mean your hair loss is hopeless or that there is nothing left to be done. It primarily means that your body reacts differently than the majority, and that you can make a different choice with that information. If you want to know how a serum compares to medication like minoxidil and finasteride, read our article on serum or medication for early hair loss. And check how long it takes for a hair serum to work before you adjust your expectations, so you know when having doubts is justified and when you just need more patience.
Frequently Asked Questions
How do I know if I am a minoxidil non-responder?
You only really notice it after a longer period of consistent use, usually four to six months. If you see no change at all in shedding or new hair, while you have applied the product correctly, there is a real chance that you have low SULT1A1 activity in your scalp. An official test is difficult to find in the Netherlands, so in practice, trying it out and evaluating is still the most common method.
How long should I try minoxidil before I can conclude that it doesn't work?
Count on at least four to six months of daily use before you can make a fair judgment. Hair follicles go through a growth cycle of several months, which means that early results are often not yet visible, even for people for whom the product eventually works. Stopping after six to eight weeks therefore says little about whether it works for you.
What exactly causes a minoxidil non-response?
The main cause is a low level of the enzyme SULT1A1 in your hair follicles, which is required to convert minoxidil into its active form. Without that conversion, the product remains largely inactive on your scalp. How much of this enzyme you have varies from person to person and appears to be partly genetically determined.
Is there a test that predicts in advance if minoxidil will work for me?
Yes, there are test kits that measure sulfotransferase activity in a plucked hair follicle, with fairly high accuracy in ruling out non-responders. The problem is availability: this test is not a standard part of Dutch healthcare and is rarely offered by GPs or dermatologists, meaning most men do not have access to it in practice.
Does a higher concentration of minoxidil help if 5 percent does nothing?
Usually not much, because a higher dose does not solve the underlying problem. If your scalp does not produce enough SULT1A1 to convert minoxidil, a higher concentration will also largely remain inactive. A higher dose mainly increases the chance of irritation and side effects, not automatically the effectiveness for a non-responder.
What can I try if minoxidil doesn't work?
Consider a product that works via a different mechanism, such as finasteride, dutasteride, or a serum with ingredients that are not dependent on the same enzyme. Always discuss medication with a doctor first due to possible side effects. For a non-medicinal route, you can look at a serum with substances like Redensyl, Procapil, or Baicapil, which act on your hair follicle in other ways.
Is it harmful to stop using minoxidil if it doesn't work?
No, stopping is not harmful in itself, but expect a temporary increase in hair loss in the first weeks after stopping. This is the so-called shedding phase, where hairs that were held onto longer by minoxidil fall out after all. In a true non-responder, this effect is usually more limited than in someone who did benefit from the product.
Does a derma roller help minoxidil work better?
A derma roller can improve the absorption of active substances by the scalp by temporarily increasing permeability. However, that does not change the amount of SULT1A1 your scalp produces, so in the case of a true enzymatic non-response, the effect remains limited. With other active ingredients, such as in a growth serum, microneedling can certainly enhance the results.
Does heredity play a role in whether minoxidil works?
Yes, the amount of SULT1A1 enzyme your scalp produces appears to be partly genetically determined. This means that if family members have responded well to minoxidil, the chance is slightly higher that you will too, but it is no guarantee. There is no widespread genetic test available yet that maps this out reliably for individuals.
Can a serum without minoxidil also slow down hair loss?
Yes, there are ingredients that do not work via the SULT1A1 enzyme but via other routes, such as activating stem cells in the hair follicle or improving local blood flow. Think of Redensyl, Procapil, Baicapil, or rosemary oil, which show their own results in clinical research independent of minoxidil. That makes such a serum a logical alternative if minoxidil does not work for you.
