Minoxidil – FolliQuest

Introduction

Minoxidil is the most effective hair growth stimulant currently available on the market.

With minimal side effects and high levels of effectiveness, minoxidil is placed squarely into the big 3 stack of gold-standard hair loss prevention, alongside finasteride and ketoconazole shampoo.

Although minoxidil is unable to stop the progression of male pattern baldness due to its lack of antiandrogenic properties, it is a very powerful hair growth agonist that can improve both hair count and thickness—an effect which is generally attributed to its strong vasodialation properties, as well as its effects on the potassium channels.

This extensive guide is going to elaborate on all the matters on interest for current and future minoxidil users: how does it work and why, what is the optimal dosage and application frequency, its potential benefits and side effects, and many more.

📝Table of contents

History

Minoxidil has a very long and interesting history, dating back to the 1950s when it was originally proposed as a potential candidate for treating ulcers – out of all things.

The compound proved to be an ineffective treatment for this ailment, but soon it was discovered that it has very strong antihypertensive properties, through the means of vasodilation. After this finding, minoxidil was FDA-approved in 1980 to be used in tablet form for severe cases of hypertension (abnormally high blood pressure).

This time, minoxidil worked: it successfully lowered blood pressure. But then, yet another peculiar side effect was noticed in patients treated with minoxidil—a substantial increase in hair growth.

Due to this remarkable effect, doctors had started to prescribe the medicine off-label to their balding patients. Unfortunately, due to the potentially dangerous side effects of the oral medication, as well as the fact that hair growth was experienced all over the body (not just the scalp), made oral minoxidil far from being an optimal solution for those suffering from hair loss.

Then, a lightbulb turned on: What if minoxidil was compounded into a topical formulation to be used exclusively on the scalp?

Subsequent studies have shown extraordinary results, showing conclusively that topical minoxidil is very effective at stimulating hair growth on the scalp, while minimizing systemic absortion and the associated negative side effects.

Shortly after, in 1988, topical minoxidil was FDA-approved to be used for treating hair loss in both men and women, making it the first treatment available on the market for this condition.

Decades later, topical minoxidil remains one of the most effective and widely used medication in the fight against hair loss.

How does minoxidil work

Despite its remarkable effectiveness and decades-long history, the exact mechanism of action for stimulating hair growth remains partially unknown.

The most widely accepted theory is that minoxidil, through its ability to open potassium channels and act as a strong vasodilator, would increase the blood flow supply available for the hair follicles.

This newly found reserve of oxygen and nutrients would allow follicles to flourish and become stronger, in an otherwise DHT-ridden, hostile environment. Healthy follicles will then be able to produce healthy, thick shafts of hair.

In addition to that, minoxidil may also act as a nitric oxide agonist, causing the shedding of the dormant hairs, and triggering the beginning of a new hair growth cycle.

Minoxidil has been shown to increase both hair count and hair shaft thickness, as well as increase the number of follicles that are in the anagen (active growth) phase of the cycle.

Minoxidil is a hair growth stimulant. Unlike finasteride, it does not have inherent anti-androgenic properties, and therefore cannot stop DHT-induced follicle miniaturization. This topic will be thoroughly discussed later in the article.

Topical vs oral minoxidil for hair loss

Although minoxidil is also still available in tablet form and is prescribed as a last-resort medication for severe cases of hypertension, taking the medication orally for combatting hair loss is strongly discouraged.

Taking minoxidil orally may result in a number of severe side effects, ranging from moderately annoying (e.g. abnormal hair growth on the face and body), to outright dangerous or even life-threatening cardiovascular complications.

And unfortunately, the trend of using oral minoxidil off-label for hair loss has gained some traction and has become increasingly popular. The primary motivating factor behind this decision is the hope of seeing better (or faster) results from minoxidil. A decision that comes with substantial risk, and no guarantees of any better outcomes.

For people who are not responding well to topical minoxidil and are disappointed at their results, there are a number of techniques and approaches that can double or even triple the efficacy of topical minoxidil in a safe manner. This topic will be covered in depth later in the article.

Topical minoxidil is the recommended, FDA-approved, tried and tested path to achieving great results in hair growth stimulation while minimizing systemic absorption and potential negative side effects.

What minoxidil concentration to use

Topical minoxidil is commonly sold in the 2% and 5% concentrations, although there are some vendors that offer a wider spectrum of concentrations outside this range.

Minoxidil, like most medication, has a dose-response effect, meaning that higher concentrations or amounts will generally yield better results, compared to the lower dosages.

However, this dose-response curve flattens abruptly at around the 5% mark, which means that further increasing the concentration beyond this point is likely not going to deliver additional benefits for minoxidil. One of the reasons for that may be minoxidil’s low solubility, which caps at about 7.5% in propylene glycol.

All things considered, the 5% concentration is the most popular choice widely used today for men suffering from hair loss. This formulation showed superior results compared to the 2% version in most clinical trials.

Liquid solution vs foam – Which is better?

Most commonly, minoxidil is sold in the form of a liquid solution that is applied on the scalp using a dropper. Its affordable price and ubiquity on the market have made the liquid solution version the most popular choice of minoxidil.

The alternative to liquid minoxidil is a foam that comes in a spray bottle. Although it usually comes at a higher price than its liquid counterpart, minoxidil foam offers some distinct benefits over the liquid solution. This has led many to choose the foam variety for their everyday hair care routine.

When it comes to clinical efficacy, studies have shown both products to be equally effective. This means that choosing between minoxidil solution or foam is purely a matter of personal preference.

Here is a summary of the pros and cons of using each version of the product:

	Liquid solution	Minoxidil Foam
Clinical efficacy	✔	✔
Cheaper price	✔	❌
Reduced scalp irritation	❌	✔
Ease of use	❌	✔
Dosage accuracy	✔	❌
Hair appearance	❌	✔

1. Clinical efficacy

First and foremost, we will start with the most relevant comparison—the clinical efficacy of hair growth stimulation.

As previously mentioned, both the liquid minoxidil solution and the foam version contain the exact same active ingredient, in the same concentration, and have been proven to have the same level of clinical efficacy. They only differ in their delivery agent (or solvent), which is pharmacologically inactive.

With identical clinical efficacies, choosing one version over another is entirely a matter of personal preference.

2. Price

Depending on the chosen brand, the liquid minoxidil solution is usually going to be cheaper than the foam version.

Since minoxidil is not an on-time purchase, and requires long-term commitment, the total anual cost of the treatment is something that needs to be taken into account.

3. Scalp irritation

Most formulations of liquid minoxidil use ethanol and propylene glycol as solvents for the active ingredient (minoxidil). Although propylene glycol improves minoxidil’s solubility and is speculated to increase the absorption into the scalp, people with sensitive skin might experience increased amounts of irritation by using this product.

For those cases, the patient can either opt for a different liquid minoxidil solution, whith a formulation that does not contain propylene glycol, or switch to minoxidil foam—which is devoid of both ethanol and propylene glycol.

Not all people are going to experience this negative side effect from the liquid solution, but those that do have this problem might see a considerable improvement in their sympthoms by switching over to the foam version.

4. Ease of use

Depending on the hair’s length and the size of the area affected by hair thinning, the minoxidil foam might be easier and quicker to apply. Using the foam version will also prevent unwanted dripping on the forehead.

Considering the fact that minoxidil is a long-term treatment that requires daily application, the ease of use is not something to be overlooked. It’s always better to choose a product that you enjoy using—a daily routine that you can commit to for the long run.

5. Dosage accuracy

When it comes to accurately measuring the dosage, the liquid minoxidil solution is going to be superior. Since it comes with a graduated dropper, it leaves very little room for error, thus enabling you to accurately apply the right dosage every single time.

The minoxidil foam can still be used with a good degree of accuracy, but it’s important to read the product label on how to correctly measure the dosage before applying the foam. The spray cap is most commonly being used as a measuring device.

6. Hair appearance

Here is where minoxidil foam is the clear winner.

Unlike its liquid counterpart, the minoxidil foam absorbs quickly, dries out very faster (5-10 minutes, compared to 30 minutes), and most importantly: it does not leave the hair with a greasy appearance.

This becomes highly relevant if you are planning on using minoxidil in the morning, before starting your day.

How to choose between the two

Fortunately, you don’t have to.

You don’t need to decide right away on a single product that you’re going to be stuck with for the foreseeable future.

Both the liquid minoxidil and the foam offer identical clinical benefits and are therefore interchangable. A great strategy is to buy both minoxidil variations, from different vendors, and experiment with different products to see which one you like using the most.

You can switch to a different minoxidil product at any time in the future.

How to apply minoxidil

1. Dosage and frequency

The standard recommendation for applying liquid minoxidil is 1ml twice per day—morning and evening. Applying more frequently than that will not result in further improvements.

However, minoxidil has a relatively long half-life, of about 20 hours. This means that a single daily application of 2 ml minoxidil will be sufficient, and will confer the same benefits—in most cases.

Using the product only once a day is not only more convenient, but may also help reduce the potential scalp-related side effects, such as irritation or redness.

If you are using minoxidil foam instead of the liquid forumulation, the amount applied needs to be the equivalent of 1 ml and 2 ml respectively. The product label should provide all the required information on how to gauge the amount of foam needed (the bottle’s cap is usually used for this purpose).

TIP: A great way to ensure that you’re not forgetting to apply your daily minoxidil is to keep the product in your bathroom and use it after brushing your teeth.

2. Application on the scalp

Minoxidil should not be applied on an irritated or inflamed scalp.

Also, when using microneedling as an adjuvant therapy, minoxidil or other topical products should not be used for at least 24 hours after micronnedling, to prevent excessive systemic absorption of the medication or further irritation to the scalp.

Make sure that the scalp is completely dry when applying minoxidil.

In order for minoxidil to be effective, it needs to make contact with the surface of the scalp. Having the product only on the hair will not yield any clinical benefits—it needs to be absorbed through the skin.

The product’s absorption rate and the amount of time required for it to dry will vary from one product to another. The foam variety of minoxidil usually dries out quicker and leaves less residue on the hair afterwards.

Initial hair shedding from minoxidil

Before we move on to the expected hair growth results, there is something that all new minoxidil users should be aware of:

The most common “side effect” experienced by a lot of people when first starting the treatment with minoxidil is a substantial increase in the amount of hair being shed.

Contrary to popular belief, this is not a negative side effect of minoxidil or a paradoxical reaction to the medication.

Instead, this initial shedding phase is one of the greatest indicators that the medication is actually working and the hair follicles are positively responding to the treatment. This is normal, expected, and should not raise any concearns—quite the contrary.

What happens when the initial hair shedding occurs, is that the hair follicles are prematurely ending their current growth cycle, in order to begin a new one, starting with the anagen (growth) phase. The old hair is being discarded in order to make room for the new, stronger and healthier hair that is growing beneath it.

Needless to say, this excessive shedding can cause panic for a lot of uninformed minoxidil first-time users. Some of them even make the mistake of stopping the medication, thinking that they experience some kind of paradoxical reaction and minoxidil is actually worsening their hair loss.

With continual usage of minoxidil, the initial shedding phase will gradually subside, and is usually completely over at around the 8 week mark. At this point, all the hair is slowly going to grow back, stronger, thicker and healthier than before, over the course of a few months.

The actual side effects of minoxidil are explained in-depth later in the article.

Minoxidil hair growth results

Minoxidil is the best available hair growth stimulant on the market, with clinical studies showing hair growth ranging from 20% up to 70%, depending on individual response to the medication.

From a visual standpoint, minoxidil may have the potential to reverse your hairloss by a whole stage on the Norwood scale (e.g. Norwood 3 becomes Norwood 2).

According to clinical research, some of the factors that increase the likeleyhood of seeing a positive response from minoxidil include:

Being younger—in your 20s and 30s
Early initiation of treatment—less than 10 years since the onset of hair loss
Having sufficiently elevated levels of a certain enzyme in the scalp (sulfotransferase SULT1A1)

Just like finasteride, early initiation of treatment with minoxidil is strongly associated with better outcomes. One of the possible reasons for that may be the fact that the hair follicles may not be damaged beyond repair in the initial stages of balding, and would therefore be much more likeley to revert back to a healthier state once the medication is intoduced.

Minoxidil’s effectiveness is highly dependent on the frequency of application. It needs to be applied on a daily basis, for prolonged periods of time. Infrequent usage or taking extended breaks from minoxidil will drastically reduce its effectiveness.

After the initial shedding phase, the first results are expected to come after at least 4 months. Even in people that do not see desirable results at the 4 month period, it is usually recommended to continue the treatment for at least 12 months before writing off minoxidil as ineffective.

For the people who are not responding well to treatment and are not seeing good results, pairing minoxidil with microneedling as an adjuvant therapy might have the potential to double or even triple the results from minoxidil, effectively turning a non-responder into a responder.

Minoxidil side effects

Topical minoxidil for hair growth is FDA-approved, it’s generally regarded as safe and is very well tolerated by the vast majority of people taking it. But just like with any other medication, minoxidil is a pharmaceutical compound that alters the body’s physiology and thus has the potential to cause side effects.

If you believe that are experiencing any kind of side effects, or have any questions or concerns, you are highly advised to discuss with your doctor or health care provider.

Besides the previously mentioned hair shedding that happens only at the beginning (which is not a side effect), here is a breakdown of the potential negative side effects of minoxidil, as well as ways to combat them:

1. Common side effects

The most commonly exhibited side effects of topical minoxidil are usually limited to the scalp area. Such symptoms may include:

Itchy scalp
Redness
Contact dermatitis
Change in hair texture

Fortunately, these symptoms are usually not attributed to minoxidil itself, but rather to the secondary, inactive ingredients that are used as solvents and delivery agents in a particular minoxidil formulation.

A common example of such an ingredient would be propylene glycol, which is often added into liquid minoxidil formulations in to increase the solvability of the medication. Propylene glycol, as well as ethanol—which is also commonly used—might increase the risk of experiencing scalp irritation.

The scalp-related side effects can be easily solved by:

Choosing a minoxidil solution that does not contain propylene glycol.
Using minoxidil foam instead of the liquid solution.
Switching to a different brand of minoxidil that is higher in quality and less harsh on the scalp.
Reducing the frequency of application (e.g. only once, instead of twice daily)
Temporary or permanent cessation of treatment—for those that cannot tolerate any type of topical minoxidil.

2. Rare side effects

Although minoxidil is FDA-approved, sold over-the-counter in most places, and is generally very well tolerated by the majority of people using it, this medication is still a very potent vasodilator and even when applied topically, a tiny amount of it (~1-2%) might still be absorbed systemically.

This can cause problems for people that are hypersensitive to minoxidil—which is very rare, but is still something that you need to keep an eye out for. Some of the rare side effects might include:

Fluid retention or swelling
Dizziness or lightheadedness
Difficulty breathing
Heart palpitations

If you believe you experience any of these symptoms, discontinuation of the medication might be advised. Discuss with your doctor or health care provider.

What happens if you stop using minoxidil

Minoxidil, like finasteride, is a long-term treatment that requires continuous usage for maintaining the results. Discontinuation of the treatment will result in the gradual loss of the newly-grown hair over a 3–6 month period.

However, this is not an overnight process. Ocasionally skipping an application or taking a few days off minoxidil will most likely not have any detrimental effects for your hair.

People may skip applying minoxidil for a number of reasons:

Problem	Potential solution
Forgetting to take minoxidil	💡 Keeping minoxidil in the bathroom and using it after brushing teeth.
Running out of minoxidil	💡 Ensuring a supply of several minoxidil bottles at home.
Stopping due to scalp irritation	💡 Switching to a different minoxidil forumation or brand.

Taking extended breaks or infrequent usage of minoxidil will lower its effectiveness. Therefore, it is important to be ready to commit to a long-term treatment plan before including minoxidil into your health care routine.

Minoxidil does NOT stop hair loss

Not an anti-androgen

This may seem like a contradiction at first, but, indeed, minoxidil does not and cannot stop hair loss.

Minoxidil is a very powerful hair growth agonist—it stimulates the growth of the hair and increases both hair count and thickness.

However, in spite of this, minoxidil does not have anti-androgenic properties. It does not lower DHT levels in the scalp, and does not alter the local metablism of this hormone in any way.

As such, minoxidil is unable to stop or reverse male pattern baldness—that is the job of finasteride, which stops androgenic alopecia in its tracks by removing DHT from the equation, thus preventing the process of follicle miniaturization.

The “minoxidil only” pitfall

Some men suffering from hair loss may choose minoxidil as the first and only line of treatment for their conditon.

While this is definitely better than doing nothing, using minoxdil as a monotherapy without first addressing the underlying cause of male pattern baldness can lead to a dangerous situation later down the line:

1. At first, minoxidil starts yielding very good results, and the newly-grown hairs outnumber the ones being lost—this results in a net-positive gain in hair count.

2. After a while, the results from minoxidil start to plateou, but are still keeping up with the numbers of hairs being lost. The hair count remains relatively stable.

3. But, eventually, the number of hairs lost due to miniaturization start to rapidly outnumber the hairs gained from minoxidil, and this is really when things start going downhill.

Once the third stage is reached, and hair begins to fall out aggressively, many patients start to panic thinking that minoxidil has suddenly stopped working after only a few short years of usage.

In reality, minoxidil was working effectively the whole time—it did its job and stimulated hair growth. But was unable to keep up with the underlying hair loss caused by follicle miniaturization, since the condition was never properly addressed in the first place.

The right strategy

Using minoxidil as a monotherapy may be a viable strategy if the male pattern baldness is very mild and is progressing slowly, or if you don’t plan on holding onto your hair for the long-term and you only want to keep it for a few more years before going bald.

However, if you are serious about maintaining your hair, it’s almost always prefferable to first discuss with your doctor about starting finasteride therapy, and properly address the underlying cause of male pattern hairloss, before incorporating minoxidil or other hair growth stimulants into your hair loss prevention protocol.

Another advantage of adding in finasteride before minoxidil, that that you will have the opportunity to assess the effectiveness—as well as observe any potential side effects—of each individual treatment.

Dealing with hair loss can be very daunting, and many patients might be tempted to throw the enitre kitchen sink at their scap. While this kind of reaction is perfectly undertandable, by using this approach you miss the chance to see what works and what doesn’t.

Conclusion

Minoxidil is the most widely used and effective hair growth stimulants on the market. It has the potential to increase both hair count and thickness.

Although it was originally prescribed as an oral antihypertensive medication, minoxidil has been repurposed as a hair loss medication due to its unique ability to stimulate hair growth. Topical minoxidil has been FDA-approved for this purpose in 1988, and has been considered a gold-standard treatment option for hair loss ever since.

In spite of its remarkable efficacy as a growth stimulator, minoxidil is unable to stop or reverse male pattern baldness, since it does not disrupt the levels of scalp DHT, leaving the process of follicl e miniaturization run its course. For this reason, using finasteride to address the underlying cause of baldness before including minoxidil into your hair loss prevention protocol might be advantageous.

Minoxidil is generally very well tolerated by most people, and the most common side-effects associated with this medication are usually mild, and are limited to the scalp area: redness, irritation or change in hair texture. However, in rare cases, people who are very sensitive to minoxidil might experience more severe adverse reactions. For this reason, it’s very important to discuss with your doctor or health care provider before starting using minoxidil or any other medication.

Minoxidil is commonly sold in the 2% and 5% concentrations, with the stronger variation showing superior results in most clinical trials. The stronger version is usually the recommended option for men suffering from androgenic alopecia.

Topical minoxidil primarily comes in two forms: liquid solution or minoxidil foam—both being equally effective. However, the former is more commonly available and usually cheaper, while the latter might be more expensive, but it is easier to apply, dries faster, leaves less residue, and might cause less scalp irritation for some people.

Similarly to finasteride, minoxidil is a long-term treatment that requires regular usage for getting and maintaining the results. Cessation of treatment will result in the loss of the newly-grown hair over a period of a few months.

🔬Scientific References:

Suchonwanit P, Thammarucha S, Leerunyakul K. Minoxidil and its use in hair disorders: a review [published correction appears in Drug Des Devel Ther. 2020 Feb 10;14:575]. Drug Des Devel Ther. 2019;13:2777-2786. Published 2019 Aug 9. doi:10.2147/DDDT.S214907
Choi N, Shin S, Song SU, Sung JH. Minoxidil Promotes Hair Growth through Stimulation of Growth Factor Release from Adipose-Derived Stem Cells. Int J Mol Sci. 2018;19(3):691. Published 2018 Feb 28. doi:10.3390/ijms19030691
Gupta AK, Venkataraman M, Talukder M, Bamimore MA. Relative Efficacy of Minoxidil and the 5-α Reductase Inhibitors in Androgenetic Alopecia Treatment of Male Patients: A Network Meta-analysis. JAMA Dermatol. 2022;158(3):266-274. doi:10.1001/jamadermatol.2021.5743
Pietrauszka K, Bergler-Czop B. Sulfotransferase SULT1A1 activity in hair follicle, a prognostic marker of response to the minoxidil treatment in patients with androgenetic alopecia: a review. Postepy Dermatol Alergol. 2022;39(3):472-478. doi:10.5114/ada.2020.99947

⚠ Disclaimer: This article does not constitute medical advice and is intended for general informational purposes only. The information in the article is not a substitute for and should never be relied upon for professional medical advice, diagnosis, or treatment. Always discuss with your doctor if you have any questions. Please read our Medical Disclaimer.