Minoxidil is probably the most widely used hair loss treatment in the world. It works for some people, is available without a prescription, and is relatively inexpensive. It makes sense that many men consider it as soon as they notice their hair thinning.
But before you start, you'll want to know what to expect. What are the side effects? How bad are they? And when is it a sign that you should stop?
We explain this honestly here.
What exactly does minoxidil do?
Minoxidil was originally a blood pressure-lowering medication. Researchers discovered that it stimulated hair growth as a side effect. This led to the well-known hair product we know today.
Applied to the scalp, minoxidil primarily works by dilating blood vessels in the scalp. This allows more nutrients and oxygen to reach the hair follicles. It also extends the growth phase of the hair, known as the anagen phase. The result is that existing hairs become longer and thicker, and dormant hair follicles can become active again.
Minoxidil does not work equally well for everyone. Guideline: if you don't see any difference after six months, it's unlikely to start working.
The most common side effects
Most side effects of topical minoxidil (the variant you apply or spray on your head) are local. They occur on or around the application site.
Skin irritation and itching
This is the most common complaint. The skin can become dry, red, or itchy. Often, this is not due to minoxidil itself, but to the carrier: propylene glycol. This substance is often found in the liquid and can cause irritation in sensitive skin. There are formulas without propylene glycol, such as foam or certain serums, which are better tolerated.
Flaking or dandruff
The combination of minoxidil and a dry scalp can lead to more flaking. This often resolves as the skin gets used to the product, or if you switch to a different formula.
Hair growth in other areas
This sounds harmless, but can be annoying. If minoxidil comes into contact with other skin, it can stimulate hair growth in unwanted areas: forehead, cheeks, neck. This happens if you don't apply the product properly or touch your face before it has dried. Tip: wash your hands immediately after application and let it dry completely before going to bed.
Headache
Some men report headaches in the first few weeks. For most, this goes away on its own as the body adjusts.
The shedding phase: normal or not?
This is when many men panic and stop, even though the product is actually starting to work.
In the first two to six weeks after starting minoxidil, more hairs may fall out than usual. This is called shedding. It feels contradictory: you're using something for hair loss, but you're losing more hair.
What actually happens: minoxidil prompts hair follicles in the resting phase (telogen phase) to enter an active growth phase. This transition pushes out dormant hairs, making room for new ones. It's a sign that the product is interacting with your hair follicles.
Shedding typically lasts two to four weeks for most people. If it continues for longer than two months or if you notice a clear increase in baldness in areas that were previously stable, it's advisable to consult a dermatologist.
Oral minoxidil: different side effects
In addition to the solution you apply to your head, there is also oral minoxidil: a tablet you take. This is available by prescription in the Netherlands.
The effect is similar, but the side effects are different because the medication circulates throughout your body.
Fluid retention
Minoxidil has a vasodilating effect. The body sometimes compensates for this by retaining fluid, which can lead to swelling in the hands, feet, or ankles.
Increased heart rate
Some people notice their heart beating faster, especially in the first few weeks. This is a direct effect of its blood pressure-lowering action.
More body hair
With oral minoxidil, excessive hair growth in areas other than the head is reported much more frequently than with topical application. This includes arms, legs, chest, or face.
Oral minoxidil is often used in low doses (0.5 to 2.5 mg) compared to the dosages originally prescribed for blood pressure. The side effects are therefore less severe, but they do exist. This is always something to discuss with a doctor before you start.
When should you stop?
Not every side effect is a reason to stop. Itching and some flaking in the first few weeks are annoying, but not dangerous. Neither is shedding.
However, stop and contact a doctor if you notice:
- Shortness of breath or irregular heartbeat
- Significant weight gain in a short time (possible fluid retention)
- Persistent dizziness or faintness
- Severe allergic reaction: severe redness, swelling, or rash
These are rare side effects, but serious signs. With topical minoxidil, systemic absorption is low, but not zero. Especially at higher concentrations or if the skin is damaged, more may enter the bloodstream.
What if you prefer not to use minoxidil?
That is a completely understandable choice. Not everyone wants to use a medication for years that they also have to stop using if they want to maintain the results. One of the most common disadvantages of minoxidil is that the results disappear as soon as you stop.
There are alternatives that work through different mechanisms. Ingredients such as Redensyl and Procapil stimulate hair growth at a cellular level, without the vasodilating effect of minoxidil. They have a different side effect profile, which is a reason for some men to choose them.
The Hairborn Growth Serum is based on this principle: active ingredients that directly address hair follicles, without the systemic effects of minoxidil. Whether that is the better choice for you depends on what you want and what your hair loss looks like.
Conclusion
Minoxidil is not a miracle cure, but it works for some people who use it seriously and consistently. The side effects can be a reason for many not to start using it. Especially the shedding phase is something many men are afraid of.
If you know what to expect, you can better assess whether it suits you. And if you decide to start: give it at least four to six months before forming an opinion.